Difference between revisions of "Neuropathology tumours"

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[[Image:Gemistocytic Astrocytoma 003.jpg|thumb|right|A brain stem [[astrocytoma]]. (WC)]]
The article covers '''tumours in neuropathology'''.  Tumours are a large part of [[neuropathology]].  [[Cytopathology]] of CNS tumours is dealt with in the article ''[[CNS cytopathology]]''.
The article covers '''tumours in neuropathology'''.  Tumours are a large part of [[neuropathology]].  [[Cytopathology]] of CNS tumours is dealt with in the article ''[[CNS cytopathology]]''.


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==Brain tumours - overview==
==Brain tumours - overview==
===Adult===
===Alphabetical===
For overview see [[:Category:Neuropathology_tumours|here]]
 
===By age group===
====Adult====
Four most common types of brain tumours:<ref>[http://neurosurgery.mgh.harvard.edu/abta/primer.htm http://neurosurgery.mgh.harvard.edu/abta/primer.htm]</ref>
Four most common types of brain tumours:<ref>[http://neurosurgery.mgh.harvard.edu/abta/primer.htm http://neurosurgery.mgh.harvard.edu/abta/primer.htm]</ref>
# Metastatic brain tumours (barely edges out primary tumours)
# Metastatic brain tumours (barely edges out primary tumours)
Line 11: Line 16:
#*[[Melanoma]].  
#*[[Melanoma]].  
#*[[Renal cell carcinoma]] (RCC).
#*[[Renal cell carcinoma]] (RCC).
# [[Glioblastoma]] (previously known as ''glioblastoma multiforme'').
# [[Glioblastoma]], IDH-wildtype.
# [[Anaplastic astrocytoma]].
# [[Astrocytoma, IDH-mutant]].
# [[Meningioma]].
# [[Meningioma]].


===Children===
====Children====
# Astrocytoma.
# [[Pilocytic astrocytoma]].
# Medulloblastoma.
# [[Medulloblastoma]].
# Ependymoma.
# [[Ependymoma]].
# Pontine glioma, often [[Diffuse midline glioma, H3 K27-altered]].


===Location (most common)===
===By location===
Certain tumours like to hang-out at certain places:<ref>URL: [http://www.msdlatinamerica.com/ebooks/DiagnosticNeuropathologySmears/files/4ce563fb7e8e48fc9ed8b42e296a7747.gif http://www.msdlatinamerica.com/ebooks/DiagnosticNeuropathologySmears/files/4ce563fb7e8e48fc9ed8b42e296a7747.gif] and [http://www.msdlatinamerica.com/ebooks/DiagnosticNeuropathologySmears/sid117213.html http://www.msdlatinamerica.com/ebooks/DiagnosticNeuropathologySmears/sid117213.html]. Accessed on: 2 November 2010.</ref>
Certain tumours like to hang-out at certain places:<ref>URL: [http://www.msdlatinamerica.com/ebooks/DiagnosticNeuropathologySmears/files/4ce563fb7e8e48fc9ed8b42e296a7747.gif http://www.msdlatinamerica.com/ebooks/DiagnosticNeuropathologySmears/files/4ce563fb7e8e48fc9ed8b42e296a7747.gif] and [http://www.msdlatinamerica.com/ebooks/DiagnosticNeuropathologySmears/sid117213.html http://www.msdlatinamerica.com/ebooks/DiagnosticNeuropathologySmears/sid117213.html]. Accessed on: 2 November 2010.</ref>
*Cerebrum:
====Cerebrum====
**Cortical based - [[oligodendroglioma]].
*Cortical based - [[oligodendroglioma]].
**Grey-white junction - metastases.
*Grey-white junction - metastases.
**White matter - astrocytoma, [[glioblastoma]].
*White matter - astrocytoma, [[glioblastoma]].
**Periventricular - CNS lymphoma.
*Periventricular - CNS lymphoma.
**Cystic - [[ganglioglioma]], [[pilocytic astrocytoma]], [[pleomorphic xanthoastrocytoma]].
*Cystic - [[ganglioglioma]], [[pilocytic astrocytoma]], [[pleomorphic xanthoastrocytoma]].
*Cerebellum:
====Cerebellum====
**Midline/central - [[medulloblastoma]].
*Midline/central - [[medulloblastoma]].
**Cystic lesion - pilocytic astrocytoma (younger individual), [[hemangioblastoma]] (older individual).
*Cystic lesion - pilocytic astrocytoma (younger individual), [[hemangioblastoma]] (older individual).
**Solid lesion (older individual) - metastasis.
*Solid lesion (older individual) - [[metastasis]].
*Spinal cord:
====Sella turcica====
**[[Ependymoma]], glioblastoma.
* [[Pituitary adenoma]].
**Filum terminale - [[myxopapillary ependymoma]], [[paraganglioma]].
* [[Craniopharyngioma]].
 
less common:
* [[Pituicytoma]].
* [[Granular cell tumour]].
* [[Germinoma]].
* [[Chordoma]]
* Rathke cleft cyst.
* Hypophysitis.
* Xanthogranuloma.
====Spinal cord====
*[[Ependymoma]]
*[[Glioblastoma]]
*[[Meningioma]]
*Carcinoma metastasis
*[[Hemangioblastoma]]
====Filum terminale====
====Filum terminale====
*Filum terminale = bottom end of the spinal cord - has a limited differential.
DDx:<ref>JLK. 31 May 2010.</ref>
*[[Meningioma]].
*[[Meningioma]].
*[[Myxopapillary ependymoma]].
*[[Myxopapillary ependymoma]].
*[[Neurofibroma]].
*[[Neurofibroma]].
*[[Schwannoma]].
*[[Schwannoma]].
*Paraganglioma.
*[[Paraganglioma]].
 
====Meninges====
====Cerebellopontine angle====
* [[Meningioma]].
DDx:<ref>R. Kiehl. 8 November 2010.</ref>
* [[Solitary fibrous tumour]] / Hemangiopericytoma.
*Schwannoma.
* [[Hemangioblastoma]].
*[[Meningioma]].
less common:
*[[Dermoid cyst]]/epidermoid cyst.
* [[Melanoma]] / Melanocytoma.
*Ependymoma.
* Lymphoproliferative diseases.
*[[Choroid plexus papilloma]].
* [[Sarcoidosis]]
* [[Arachnoid cyst]].
* Disseminated oligodendroglial-like leptomeningeal tumour.
* Desmoplastic infantile astrocytoma / ganglioglioma.
* Meningioangiomatosis.
* Calcifying pseudoneoplasm.
====Skull====
* [[Fibrous dysplasia]].
* [[Paget disease]].
* [[Histiocytosis]].
* [[Hemangioma]].
* [[Aneurysmal bone cyst]].
* [[Plasma_cell_neoplasms#Multiple_myeloma|Multiple myeloma]].
====Skull base / Cerebellopontine angle====
* [[Schwannoma]].
* [[Meningioma]].
* [[Dermoid cyst]] / epidermoid cyst.
less common:
* [[Ependymoma]].
* [[Choroid plexus papilloma]].
* [[Glomus tumour]].
* [[Chordoma]].
* [[Chondrosarcoma]].
* [[Olfactory neuroblastoma]].
* [[Endolymphatic sac tumour]].


===Cystic tumours===
===Primary versus secondary===
DDx:<ref>URL: [http://path.upmc.edu/cases/case320/dx.html http://path.upmc.edu/cases/case320/dx.html]. Accessed on: 14 January 2012.</ref>
*[[AKA]] (primary) brain tumour versus metastatic cancer.
*[[Pilocytic astrocytoma]].
*[[Pleomorphic xanthoastrocytoma]].
*[[Ganglioglioma]].
*[[Hemangioblastoma]].
*[[Craniopharyngioma]].<ref>URL: [http://www.pathologyoutlines.com/Cnstumor.html#cystsgeneral http://www.pathologyoutlines.com/Cnstumor.html#cystsgeneral]. Accessed on: 14 January 2012.</ref>
 
===Primary vs. secondary (metastatic)===
====Primary====
====Primary====
Glial tumours:
[[Glioma|Glial tumours]]:
*Cytoplasmic processes - '''key feature'''.
*Cytoplasmic processes - '''key feature'''.
**Best seen at highest magnification - usu. ~1 micrometer.
**Best seen at highest magnification - usu. ~1 micrometer.
**Processes may branch.
**Processes may branch.
*Ill-defined border/blend with the surrounding brain.
*Ill-defined border/blend with the surrounding brain.
[[Meningioma]]:
*Lesion often dura-based.
*Mesenchymal tumor (often contains collagen).


[[Lymphoma]]:
[[Lymphoma]]:
*Primary CNS Lymphoma (PCNSL) is usu. a diffuse large B-cell lymphoma.
*Large (lymphoid) cells, ergo usu. not a difficult diagnosis.
*Large (lymphoid) cells, ergo usu. not a difficult diagnosis.
**~2x size of resting lymphocyte, nucleoli.
**~2x size of resting lymphocyte, nucleoli.
*Lesion predominantly perivascular.  
*Lesion predominantly perivascular.


====Secondary====
====Secondary====
Carcinomas:
*Carcinomas:
*Well-demarcated border between brain and lesion - '''key feature'''.
**Well-demarcated border between brain and lesion - '''key feature'''.
*No cytoplasmic processes.
**No cytoplasmic processes.
*Usu. have nuclear atypia of malignancy.
**Usu. have nuclear atypia of malignancy.
**Nuclei often ~3-4x the size of a [[RBC]].
**Nuclei often ~3-4x the size of a [[RBC]].
*+/-Glandular arrangement.
**+/-Glandular arrangement.
*+/-Nucleoli.
**+/-Nucleoli.
*Melanoma.
*Secondary Lymphoma.
*Sarcomas (rare).
 
===By growth pattern===
====Infiltrative astrocytomas====
*[[Astrocytoma, IDH-mutant]].
*[[Glioblastoma]], IDH-wildtype.
 
Notes:
**Glial: "blends into brain"/gradual transition to non-tumour brain.
 
====Non-infiltrative astrocytomas====
**[[Pilocytic astrocytoma]]
**[[Pleomorphic xanthoastrocytoma]]
**[[Subependymal giant cell astrocytoma]].
 
====Cystic tumours====
DDx:<ref>URL: [http://path.upmc.edu/cases/case320/dx.html http://path.upmc.edu/cases/case320/dx.html]. Accessed on: 14 January 2012.</ref>
*[[Pilocytic astrocytoma]].
*[[Pleomorphic xanthoastrocytoma]].
*[[Ganglioglioma]].
*[[Hemangioblastoma]].
*[[Craniopharyngioma]].<ref>URL: [http://www.pathologyoutlines.com/Cnstumor.html#cystsgeneral http://www.pathologyoutlines.com/Cnstumor.html#cystsgeneral]. Accessed on: 14 January 2012.</ref>
 
 
Notes:
**Non-glial: no radiating glial processes.
*Rosenthal fibres within the tumour... often seen in [[pilocytic astrocytoma]].
**Rosenthal fibres may be seen around a (very) slow growing tumour and represent a reactive process.
*Inflammatory cells and macrophages should prompt consideration of an alternate diagnosis (e.g. [[cerebral infarct]], [[multiple sclerosis]]) - esp. if this is a primary lesion.<ref>URL: [http://path.upmc.edu/cases/case79/dx.html http://path.upmc.edu/cases/case79/dx.html]. Accessed on: 2 January 2012.</ref>
 
====Grading====
Nuclear pleomorphism present:
*At least grade II (diffuse astrocytoma).
 
Mitotic figures present:
*At least grade III (anaplastic astrocytoma).
 
Microvascular proliferation ''or'' necrosis with pseudopalisading tumour cells:
*Grade IV (glioblastoma [[AKA]] glioblastoma multiforme).
 
Notes:
*Pseudopalisading tumour cells = high tumour cell density adjacent to regions of necrosis; palisade = a fence of poles forming a defensive barrier or fortification.
*WHO Grading is currently based on expected biologiocal behaviour without treatment.
**Grading does not reflect molecular divergent groups within a tumor class  or response to therapy (Currently controversies in grading for IDH-mutant astrocytoma vs. IDH-wildtype astrocytoma).<ref>{{Cite journal  | last1 = Louis | first1 = DN. | last2 = von Deimling | first2 = A. | title = Grading of diffuse astrocytic gliomas: Broders, Kernohan, Zülch, the WHO… and Shakespeare. | journal = Acta Neuropathol | volume =  | issue =  | pages =  | month = Aug | year = 2017 | doi = 10.1007/s00401-017-1765-z | PMID = 28801693 }}</ref>
 
===By IHC===
*GFAP - should stain cytoplasm of tumour cells and the perikaryon (nuclear membrane) of most [[Astrocytoma]]s.
*[[IDH-1]](R132H) (isocitrate dehydrogenase 1) in [[Astrocytoma, IDH-mutant]].<ref name=pmid19228619>{{cite journal |author=Yan H, Parsons DW, Jin G, ''et al.'' |title=IDH1 and IDH2 mutations in gliomas |journal=N. Engl. J. Med. |volume=360 |issue=8 |pages=765–73 |year=2009 |month=February |pmid=19228619 |pmc=2820383 |doi=10.1056/NEJMoa0808710 |url=}}</ref><ref name=pmid20975057>{{cite journal |author=Houillier C, Wang X, Kaloshi G, ''et al.'' |title=IDH1 or IDH2 mutations predict longer survival and response to temozolomide in low-grade gliomas |journal=Neurology |volume=75 |issue=17 |pages=1560–6 |year=2010 |month=October |pmid=20975057 |doi=10.1212/WNL.0b013e3181f96282 |url=}}</ref>
*[[H3F3A|H3F3A K27M]] in [[Diffuse midline glioma, H3 K27-altered]].
*[[ATRX]] -ve in [[Astrocytoma, IDH-mutant]] or [[Diffuse hemispheric glioma, H3 G34-mutant]].
*[[CD20]] in PCNSL.
*Cytokeratins in Carcinoma brain metastases, Plexus choroid tumours, [[AT/RT]], [[Papillary tumour of the pineal region]], [[Craniopharyngioma]].
*[[EMA]] in [[Meningioma]] and carcinoma brain metastases.
*PrgR in [[Meningioma]] and carcinoma metastases.
*[[Synaptophysin]] in glioneuronal tumours and Pituitary adenoma and embryonal tumours.


===Common neuropathology tumours in a table===
===Common neuropathology tumours in a table===
Line 100: Line 195:
|missed lesion?
|missed lesion?
|nil
|nil
|[http://commons.wikimedia.org/wiki/File:Grey_matter_and_white_matter_-_very_high_mag.jpg very high mag.], [http://commons.wikimedia.org/wiki/File:Grey_matter_and_white_matter_-_high_mag.jpg high mag.]
|[[Image:Grey_matter_and_white_matter_-_very_high_mag.jpg |thumb|center|150px|Normal. (WC)]]
|-
|-
|[[Reactive astrocytes]]
|[[Reactive astrocytes]]
Line 107: Line 202:
|variable
|variable
|missed lesion / close to a lesion; non-specific pathologic process - need more tissue
|missed lesion / close to a lesion; non-specific pathologic process - need more tissue
|nil
|GFAP
|[http://commons.wikimedia.org/wiki/File:Reactive_astrocytes_-_lfb_-_high_mag.jpg high mag.]
|[[Image:Reactive_astrocytes_-_lfb_-_high_mag.jpg|thumb|center|150px|Reactive astrocytes. (WC)]]
|-
|[[Schwannoma]]
|cellular areas (Antoni A), paucicelluar areas (Antoni B), palisading of nuclei (Verocay bodies)
|extra-axial + intradural
|old or young
|need frozen section to Dx, DDx: [[meningioma]]
|S100, SOX10
|[[Image:Schwannoma_-_Antoni_A_and_B_-_very_high_mag.jpg|thumb|center|150px|Schwannoma. (WC)]]
|-
|[[Meningioma]]
|whorls, psammomatous calcs, nuclear inclusions
|extra-axial + intradural
|old or young
|may be diagnosed on smear, DDx: [[schwannoma]], choroid plexus
|EMA, PR, Ki-67
|[[Image:Meningioma_intermed_mag.jpg |thumb|center|150px|Meningioma. (WC)]]
|-
|[[Astrocytoma, IDH-mutant]] (CNS [[WHO]] grade 2 or grade 3)
|glial processes (esp. on smear), nuclear atypia (typical size var. ~3x, irreg. nuc. membrane, hyperchromasia), no Rosenthal fibres in the core of the lesion †, no microvascular proliferation, no necrosis
|often enhancing (suggests high grade), usu. supratentorial, usu. white matter
|usu. old, occ. young
|common
|IDH-1(R132H)+/-, GFAP+
| [[Image:Anaplastic_astrocytoma_-_very_high_mag_-_cropped.jpg | thumb| center| 150px|High-grade astrocytoma. (WC)]]
|-
|-
|[[Astrocytoma]] (grade II or worse)
|[[Glioblastoma]], IDH-wildtype (CNS [[WHO]] grade 4)
|glial processes (esp. on smear), nuclear atypia (size var. ~3x, irreg. nuc. membrane, hyperchromasia), no Rosenthal fibres in the core of the lesion †
|glial processes (esp. on smear), nuclear atypia (typical size var. ~3x, irreg. nuc. membrane, hyperchromasia), no Rosenthal fibres in the core of the lesion †, microvascular proliferation or necrosis
|often enhancing (suggests high grade), usu. supratentorial, usu. white matter
|often enhancing (suggests high grade), usu. supratentorial, usu. white matter
|usu. old, occ. young
|usu. old, occ. young
|very common, esp. glioblastoma
|very common, esp. glioblastoma
|IDH-1+/-, GFAP+
|IDH-1+/-, GFAP+
|[http://commons.wikimedia.org/wiki/File:Anaplastic_astrocytoma_-_high_mag.jpg high mag.], [http://commons.wikimedia.org/wiki/File:Anaplastic_astrocytoma_-_very_high_mag_-_cropped.jpg very high mag.]
| [[Image:Glioblastoma (1).jpg | thumb| center| 150px|Glioblastoma. (WC)]]
|-
|-
|Metastasis
|[[Metastatic brain tumours|Metastasis]]
|sharp interface with brain, often glandular, +/-nucleoli, no glial processes
|sharp interface with brain, often glandular, +/-nucleoli, no glial processes
|often cerebellular, well-circumscribed
|often cerebellular, well-circumscribed
|usu. old
|usu. old
|often suspected to have metastatic disease
|often suspected to have metastatic disease
|TTF-1, CK7, CK20, BRST-2
|[[TTF-1]], CK7, [[CK20]], BRST-2
|[http://commons.wikimedia.org/w/index.php?title=File:Metastatic_adenocarcinoma_-_cerebellum_-_very_low_mag.jpg very low mag.], [http://commons.wikimedia.org/w/index.php?title=File:Metastatic_adenocarcinoma_-_cerebellum_-_high_mag.jpg high mag.]
|[[Image:Metastatic_adenocarcinoma_-_cerebellum_-_very_low_mag.jpg | thumb| center|150px |Metastasis. (WC)]]
|-
|[[Meningioma]]
|whorls, psammomatous calcs, nuclear inclusions
|extra-axial + intradural
|old or young
|may be diagnosed on smear, DDx: choroid plexus, schwannoma
|EMA, PR, Ki-67
|[http://commons.wikimedia.org/wiki/File:Meningioma_intermed_mag.jpg intermed. mag.]
|-
|[[Schwannoma]]
|cellular areas (Antoni A), paucicelluar areas (Antoni B), palisading of nuclei (Verocay bodies)
|extra-axial + intradural
|old or young
|need frozen section to Dx
|S100
|[http://commons.wikimedia.org/wiki/File:Schwannoma_-_Antoni_A_and_B_-_intermed_mag.jpg intermed. mag.],
[http://commons.wikimedia.org/wiki/File:Schwannoma_-_Antoni_A_and_B_-_very_high_mag.jpg very high mag.]
|}
|}
† Rosenthal fibres at the periphery of a lesion are a non-specific finding seen in chronic processes.
† Rosenthal fibres at the periphery of a lesion are a non-specific finding seen in chronic processes.


==Metastatic tumours==
==Brain metastasis==
===General===
{{Main|Brain metastasis}}
*Most common brain tumour in adults.
 
 
===Molecular===
See also:  [[Molecular_pathology_tests#Neuropathology|Molecular Neuropathology]]


===Microscopic===
==Gliomas==
Features:
{{Main|Glioma}}
*Vary by subtype.


Images:
Gliomas, glioneuronal tumours and neuronal tumours are often categorized together.
*[http://commons.wikimedia.org/wiki/File:Metastatic_adenocarcinoma_-_cerebellum_-_very_low_mag.jpg CRC metastasis to cerebellum - very low mag. (WC)].
*[http://commons.wikimedia.org/wiki/File:Metastatic_adenocarcinoma_-_cerebellum_-_high_mag.jpg CRC metastasis to cerebellum - high mag. (WC)].


==Infiltrative astrocytomas==  
===Astrocytic tumours===
{{Main|Astrocytoma}}
{{Main|Astrocytoma}}


===Overview===
* [[Astrocytoma]], IDH-mutant.
*Low-grade (diffuse) astrocytomas (Grade II).
* [[Glioblastoma]], IDH-wildtype.
*Anaplastic astrocytomas (Grade III).
** [[Gliosarcoma]] (a glioblastoma subtype)
*Glioblastoma (Grade IV).
 
Notes:
*Non-infiltrative gliomas:
**[[Pilocytic astrocytoma]] (WHO Grade I).  
**[[Dysembryoplastic neuroepithelial tumour]] (DNT), (WHO Grade I).


===Microscopic===
Features:<ref name=pmid>{{cite journal |author=Rong Y, Durden DL, Van Meir EG, Brat DJ |title='Pseudopalisading' necrosis in glioblastoma: a familiar morphologic feature that links vascular pathology, hypoxia, and angiogenesis |journal=J. Neuropathol. Exp. Neurol. |volume=65 |issue=6 |pages=529–39 |year=2006 |month=June |pmid=16783163 |doi= |url=}}</ref><ref>[http://dictionary.reference.com/browse/palisading http://dictionary.reference.com/browse/palisading]</ref>
Features:<ref name=pmid>{{cite journal |author=Rong Y, Durden DL, Van Meir EG, Brat DJ |title='Pseudopalisading' necrosis in glioblastoma: a familiar morphologic feature that links vascular pathology, hypoxia, and angiogenesis |journal=J. Neuropathol. Exp. Neurol. |volume=65 |issue=6 |pages=529–39 |year=2006 |month=June |pmid=16783163 |doi= |url=}}</ref><ref>[http://dictionary.reference.com/browse/palisading http://dictionary.reference.com/browse/palisading]</ref>
*Glial processes - '''key feature'''.
*Glial processes - '''key feature'''.
Line 181: Line 276:
*[http://path.upmc.edu/cases/case368.html Gemistocytic astrocytoma - several images (upmc.edu)].
*[http://path.upmc.edu/cases/case368.html Gemistocytic astrocytoma - several images (upmc.edu)].


Notes:
Depreceated:
*Glial vs. non-glial tumours:
* Diffuse [[Astrocytoma]]
**Glial: "blends into brain"/gradual transition to non-tumour brain.
* [[Anaplastic astrocytoma]]
**Non-glial: no glial processes.
* [[Gliomatosis cerebri]]
*Rosenthal fibres within the tumour... make it into a [[pilocytic astrocytoma]].
* Spongioblastoma
**Rosenthal fibres may be seen around a (very) slow growing tumour and represent a reactive process.
*Inflammatory cells and macrophages should prompt consideration of an alternate diagnosis (e.g. [[cerebral infarct]], [[multiple sclerosis]]) - esp. if this is a primary lesion.<ref>URL: [http://path.upmc.edu/cases/case79/dx.html http://path.upmc.edu/cases/case79/dx.html]. Accessed on: 2 January 2012.</ref>


====Grading====
===Oligodendroglial tumours===
Nuclear pleomorphism present:
* [[Oligodendroglioma]], IDH-mutant and 1p/19q codeleted.
*At least grade II (diffuse astrocytoma).


Mitotic figures present:
Depreceated:
*At least grade III (anaplastic astrocytoma).
* Anaplastic oligodendroglioma
* [[Oligoastrocytoma]]
* Anaplastic oligoastrocytoma


Microvascular proliferation ''or'' necrosis with pseudopalisading tumour cells:
===Pediatric-type diffuse high-grade glioma===
*Grade IV (glioblastoma [[AKA]] glioblastoma multiforme).
{{Main|Pediatric-type diffuse high-grade glioma}}
* [[Astrocytoma#Diffuse_midline_glioma.2C_H3_K27M_mutant|Diffuse midline glioma H3 K27-mutant]]


Notes:
===Pediatric-type diffuse low-grade glioma===
*Pseudopalisading tumour cells = high tumour cell density adjacent to regions of necrosis; palisade = a fence of pales forming a defense barrier or fortification.
{{Main|Pediatric-type diffuse low-grade glioma}}


Images:
*Glioblastoma:
**[http://commons.wikimedia.org/wiki/File:Glioblastoma_%281%29.jpg Glioblastoma - pseudopalisading of tumour cells (WC)].
**[http://commons.wikimedia.org/wiki/File:Glioblastoma_-_high_mag.jpg Glioblastoma with fragment of near-normal white matter - high mag. (WC)].
*Anaplastic astrocytoma:
**[http://commons.wikimedia.org/wiki/File:Anaplastic_astrocytoma_-_very_high_mag_-_cropped.jpg Anaplastic astrocytoma - very high mag. (WC)].
**[http://commons.wikimedia.org/wiki/File:Anaplastic_astrocytoma_-_gfap_-_very_high_mag.jpg Anaplastic astrocytoma - GFAP - very high mag. (WC)].


=====Table of common gliomas - grading=====
===Circumscribed astrocytic gliomas===
Histomorphologic comparison of common gliomas:
* [[Pilocytic astrocytoma]] (PA)
{| class="wikitable"
** [[Pilomyxoid astrocytoma]] (PMA)
|'''Entity''' || '''Rosenthal <br>fibres / EGBs''' ||'''Nuclear atypia''' ||'''Mitoses''' || '''Necrosis or MVP''' || '''Infiltrative''' || '''Image'''
* [[Pleomorphic xanthoastrocytoma]] (PXA)
|-
* [[Subependymal giant cell astrocytoma]] (SEGA)
|Pilocytic astrocytoma || yes || usu. no || usu. no || usu. no || no || [http://commons.wikimedia.org/wiki/File:Rosenthal_HE_40x.jpg]
* [[Neuropathology_tumours#Astroblastoma|Astroblastoma MN1-altered]].
|-
* [[Neuropathology_tumours#Chordoid glioma of the third ventricl|Chordoid glioma]].
|Low-grade astrocytoma || no || yes || no || no || yes || image?
|-
|Anaplastic astrocytoma || no || yes || yes || no || yes || [http://commons.wikimedia.org/wiki/File:Anaplastic_astrocytoma_-_high_mag.jpg]
|-
|Glioblastoma || no || yes || yes || yes || yes || [http://commons.wikimedia.org/wiki/File:Glioblastoma_-_high_mag.jpg]
|}
Notes:
*''MVP'' = microvascular proliferation.
*''EGBs'' = eosinophilic granular bodies.


===IHC===
====Astroblastoma====
*GFAP - should stain cytoplasm of tumour cells and the perikaryon (nuclear membrane).
*No WHO grade yet.<ref>{{Ref WHOCNS|88}}</ref>
*Ki-67 - usu. high >20% of cells.
*Very rare superficial tumor of young age.<ref>{{Cite journal  | last1 = Narayan | first1 = S. | last2 = Kapoor | first2 = A. | last3 = Singhal | first3 = MK. | last4 = Jakhar | first4 = SL. | last5 = Bagri | first5 = PK. | last6 = Rajput | first6 = PS. | last7 = Kumar | first7 = HS. | title = Astroblastoma of cerebrum: A rare case report and review of literature. | journal = J Cancer Res Ther | volume = 11 | issue = 3 | pages = 667 | month =  | year =  | doi = 10.4103/0973-1482.140800 | PMID = 26458709 }}</ref>
*p53 - often +ve.
*Large, cystic. Pushing margin towards CNS.
*IDH1 (isocitrate dehydrogenase 1).
*Vasocentric growth, plump cells with absence of fibrillary pattern.
**+ve in tumours that arose from low-grade gliomas.<ref name=pmid19228619>{{cite journal |author=Yan H, Parsons DW, Jin G, ''et al.'' |title=IDH1 and IDH2 mutations in gliomas |journal=N. Engl. J. Med. |volume=360 |issue=8 |pages=765–73 |year=2009 |month=February |pmid=19228619 |pmc=2820383 |doi=10.1056/NEJMoa0808710 |url=}}</ref>
*GFAP+ve, Synaptohysin-ve, Olig-2-ve, focally EMA/panCK+ve. MIB-1: 1-18 %.
***Image: [http://en.wikipedia.org/wiki/File:IDH1_GBM_20x.jpg IDH1 +ve in glioblastoma (WP)].
*Molecular profile overlaps with classical [[CNS-PNET]].
**Gene fusions invoving meningioma gene (MN1)<ref>{{Cite journal | last1 = Sturm | first1 = D. | last2 = Orr | first2 = BA. | last3 = Toprak | first3 = UH. | last4 = Hovestadt | first4 = V. | last5 = Jones | first5 = DT. | last6 = Capper | first6 = D. | last7 = Sill | first7 = M. | last8 = Buchhalter | first8 = I. | last9 = Northcott | first9 = PA. | title = New Brain Tumor Entities Emerge from Molecular Classification of CNS-PNETs. | journal = Cell | volume = 164 | issue = 5 | pages = 1060-72 | month = Feb | year = 2016 | doi = 10.1016/j.cell.2016.01.015 | PMID = 26919435 }}</ref>


Notes:
*IDH1 and IDH2 mutations - better survival.<ref name=pmid20975057>{{cite journal |author=Houillier C, Wang X, Kaloshi G, ''et al.'' |title=IDH1 or IDH2 mutations predict longer survival and response to temozolomide in low-grade gliomas |journal=Neurology |volume=75 |issue=17 |pages=1560–6 |year=2010 |month=October |pmid=20975057 |doi=10.1212/WNL.0b013e3181f96282 |url=}}</ref>


==Pilocytic astrocytoma==
<gallery>
===General===
File:Astroblastoma_HE_Specimen.jpg | HE. (WC/jensflorian)
*Low-grade astrocytoma.  
File:Astroblastoma_HE_papillae.jpg | HE. (WC/jensflorian)
*Classically in the cerebellum in children; most common glioma in children.<ref name=Ref_PSNP82>{{Ref PSNP|82}}</ref>
File:Astroblastoma.jpg | Astroblastoma (AFIP)
*The ''optic glioma'' associated with neurofibromatosis 1.
</gallery>


===Gross===
====Chordoid glioma of the third ventricle====
Features:<ref name=Ref_PSNP82>{{Ref PSNP|82}}</ref>
* WHO grade II.
*Usually well-circumscribed.
* Slowly growing, non-invasive, in adults.
*Cystic ''or'' solid.
* Clusters of epithelioid cells in mucinous stroma.
*Do '''not''' smear. (Ref. ?)
* Lymphocytic infiltrates, adjacent Rosenthal fibers.
* Fibrosis may be present.
* Few mitoses.
* [[GFAP]]+ve,  MIB-1 1-3%.
* [[TTF-1]]+ve.
* CD34+ve.
* [[IDH-1]]-ve, [[p53]]-ve.
* PRKCA D463H mutations.<ref>{{Cite journal  | last1 = Goode | first1 = B. | last2 = Mondal | first2 = G. | last3 = Hyun | first3 = M. | last4 = Ruiz | first4 = DG. | last5 = Lin | first5 = YH. | last6 = Van Ziffle | first6 = J. | last7 = Joseph | first7 = NM. | last8 = Onodera | first8 = C. | last9 = Talevich | first9 = E. | title = A recurrent kinase domain mutation in PRKCA defines chordoid glioma of the third ventricle. | journal = Nat Commun | volume = 9 | issue = 1 | pages = 810 | month = 02 | year = 2018 | doi = 10.1038/s41467-018-02826-8 | PMID = 29476136 }}</ref>


===Microscopic===
<gallery>
Features:<ref name=Ref_PSNP82-4>{{Ref PSNP|82-4}}</ref>
File:NP op 20201028 009.jpg | Chordoid Glioma. (WC/jensflorian)
*Classically biphasic (though either may be absent):
</gallery>
*#Fibrillar.
*#Microcystic/loose.
*Hair-like fibres ~ 1 micrometer; ''pilo-'' = hair.<ref>URL: [http://dictionary.reference.com/browse/pilo- http://dictionary.reference.com/browse/pilo-]. Accessed on: 24 November 2010.</ref>
**Best seen on smear or with GFAP [[IHC]].
*Rosenthal fibres - '''key feature'''.
**May be rare.  Not pathognomonic (see below).
*Eosinophilic granular bodies.
*Low cellularity - when compared to medulloblastoma and ependymoma.


Notes:
*+/-Microvascular proliferation.
*+/-Focal necrosis.
**Necrosis with pseudopalisading more likely glioblastoma.
*+/-Mitoses - not significant in the context of the Dx.


DDx (of Rosenthal fibers):<ref>MUN. 9 Mar 2009.</ref>
===Ependymal tumours===
*Chronic reactive gliosis.
* [[Subependymoma]]
*Subependymoma.
* [[Myxopapillary Ependymoma]]
*Ganglioma.
* [[Ependymoma]]
*Alexander's disease (rare leukodystrophy).
* Anaplastic ependymoma


DDx of pilocystic astrocytoma (brief):
==Choroid plexus tumours==
*Piloid gliosis.
* [[Choroid plexus papilloma]]
*Oligodendroglioma.
* Atypical choroid plexus papilloma
*Glioblastoma (uncommon - but important).
* [[Choroid plexus carcinoma]]


Images:
==Other neuroepithelial tumours==
*Smears:
* [[Neuropathology_tumours#Cribiform_neuroepithelial_tumour|Cribifiorm neuroepithelial tumour]].
**[http://commons.wikimedia.org/wiki/File:Pilocytic_astrocytoma_-_smear_-_very_high_mag.jpg Bipolar cells with hair-like processes - smear - very high mag. (WC)].
**[http://commons.wikimedia.org/wiki/File:Pilocytic_Micro.jpg EGBs - smear (WC/AFIP)].
**[http://commons.wikimedia.org/wiki/File:Rosenthal_fibers.jpg Rosenthal fibres - smear (WC/AFIP)].
*Sections:
**[http://commons.wikimedia.org/wiki/File:Rosenthal_HE_40x.jpg Rosenthal fibres (WC)].
**[http://moon.ouhsc.edu/kfung/jty1/neurotest/Q19-Ans.htm Rosenthal fibre (ouhsc.edu)].
**[http://path.upmc.edu/cases/case162.html Pilocytic astrocytoma (upmc.edu)].
**[http://path.upmc.edu/cases/case90.html Pilocytic astrocytoma - another case (upmc.edu)].
**[http://path.upmc.edu/cases/case195/images/figure3b.jpg Pilocytic astrocytoma - pennies on a plate (upmc.edu)].<ref>URL: [http://path.upmc.edu/cases/case195.html http://path.upmc.edu/cases/case195.html]. Accessed on: 8 January 2012.</ref>
**[http://path.upmc.edu/cases/case397.html Pilocytic astrocytoma (upmc.edu)].


===IHC/special stains===
Features:<ref name=Ref_PSNP84>{{Ref PSNP|84}}</ref>
*GFAP +ve (fibres).
*PAS-D: eosinophilic granular bodies +ve.
*CD68: may have a significant macrophage component.
*KI-67: may be "high" (~20% ???).


===Grading===
===Cribiform neuroepithelial tumour===
*''WHO Grade I'' by definition.
AKA: '''CRINET'''.
*Not listed in the current WHO classification.
*First description in 2009.<ref>{{Cite journal  | last1 = Hasselblatt | first1 = M. | last2 = Oyen | first2 = F. | last3 = Gesk | first3 = S. | last4 = Kordes | first4 = U. | last5 = Wrede | first5 = B. | last6 = Bergmann | first6 = M. | last7 = Schmid | first7 = H. | last8 = Frühwald | first8 = MC. | last9 = Schneppenheim | first9 = R. | title = Cribriform neuroepithelial tumor (CRINET): a nonrhabdoid ventricular tumor with INI1 loss and relatively favorable prognosis. | journal = J Neuropathol Exp Neurol | volume = 68 | issue = 12 | pages = 1249-55 | month = Dec | year = 2009 | doi = 10.1097/NEN.0b013e3181c06a51 | PMID = 19915490 }}</ref>
*Around ventricles.<ref>{{Cite journal  | last1 = Arnold | first1 = MA. | last2 = Stallings-Archer | first2 = K. | last3 = Marlin | first3 = E. | last4 = Grondin | first4 = R. | last5 = Olshefski | first5 = R. | last6 = Biegel | first6 = JA. | last7 = Pierson | first7 = CR. | title = Cribriform neuroepithelial tumor arising in the lateral ventricle. | journal = Pediatr Dev Pathol | volume = 16 | issue = 4 | pages = 301-7 | month =  | year =  | doi = 10.2350/12-12-1287-CR.1 | PMID = 23495723 }}</ref>
*Young children.<ref>{{Cite journal  | last1 = Park | first1 = JY. | last2 = Kim | first2 = E. | last3 = Kim | first3 = DW. | last4 = Chang | first4 = HW. | last5 = Kim | first5 = SP. | title = Cribriform neuroepithelial tumor in the third ventricle: a case report and literature review. | journal = Neuropathology | volume = 32 | issue = 5 | pages = 570-6 | month = Oct | year = 2012 | doi = 10.1111/j.1440-1789.2011.01293.x | PMID = 22239490 }}</ref>
*Small undifferentiated cells arranged in cribriform strands and trabeculae of varying thickness.
*MAP2+ve, Synaptophysin+ve, CK+/-ve. MIB-1: 30%.
*INI-1 loss, but no rhabdoid features and good prognosis.
*Stable genomic profile.<ref>{{Cite journal  | last1 = Gessi | first1 = M. | last2 = Japp | first2 = AS. | last3 = Dreschmann | first3 = V. | last4 = Zur Mühlen | first4 = A. | last5 = Goschzik | first5 = T. | last6 = Dörner | first6 = E. | last7 = Pietsch | first7 = T. | title = High-Resolution Genomic Analysis of Cribriform Neuroepithelial Tumors of the Central Nervous System. | journal = J Neuropathol Exp Neurol | volume = 74 | issue = 10 | pages = 970-4 | month = Oct | year = 2015 | doi = 10.1097/NEN.0000000000000239 | PMID = 26352987 }}</ref>


==Pleomorphic xanthoastrocytoma==
==Neuronal and mixed neuronal/glial tumours==
*Abbreviated ''PXA''.
* [[Desmoplastic infantile astrocytoma]] / ganglioglioma (DIA/DIG)
===General===
* [[Dysembryoplastic neuroepithelial tumour]]
Features:
* [[Central Neurocytoma]] / Extraventricular [[neurocytoma]]
*Classically in the temporal lobe in children and young adults.
* Cerebellar liponeurocytoma
*Associated with seizures.
* [[Papillary glioneuronal tumour]] (PGNT)
* [[Rosette-forming glioneuronal tumour of the fourth ventricle]] (RGNT)
* Gangliocytoma / Ganglioglioma
* Dysplastic ganglioglioma of the cerebellum ([[Lhermitte-Duclos disease]])
* [[Paraganglioma]]


===Microscopic===
===Desmoplastic infantile astrocytoma / Desmoplastic infantile ganglioglioma===
Features:<ref name=Ref_PBoD8_1333>{{Ref PBoD8|1333}}</ref>
* Abbreviated ''DIA'' or ''DIG''.
*Marked nuclear atypia.
* ICD-O code: 9412/1
*Inflammation (chronic).
* Large, superficial, cystic tumor of the infancy.
* Biologic course corresponds to WHO grade I.
* Very rare, included in the WHO since 1993.
* Prominent desmoplastic stroma.
* Astrocytic cells within stroma.
**GFAP+.
**MIB-1 usu. 1%.
* Frequent BRAF V600E or V600D mutations.<ref>{{Cite journal  | last1 = Wang | first1 = AC. | last2 = Jones | first2 = DTW. | last3 = Abecassis | first3 = IJ. | last4 = Cole | first4 = BL. | last5 = Leary | first5 = SES. | last6 = Lockwood | first6 = CM. | last7 = Chavez | first7 = L. | last8 = Capper | first8 = D. | last9 = Korshunov | first9 = A. | title = Desmoplastic Infantile Ganglioglioma/Astrocytoma (DIG/DIA) are Distinct Entities with Frequent BRAFV600 Mutations. | journal = Mol Cancer Res | volume =  | issue =  | pages =  | month = Jul | year = 2018 | doi = 10.1158/1541-7786.MCR-17-0507 | PMID = 30006355 }}</ref>
*Single case with BRAF indel or BRAF fusion.
<gallery>
File:DIG-histology.jpg | Histopathology of DIG (HE stain)
File:DIG-histology2.jpg | Prominent ganglioid cells in DIG (HE stain)
</gallery>


Notes:
===Cerebellar liponeurocytoma===
*No mitoses.
* Previously called ''lipomatous medulloblastoma'' (name changed in WHO 2000).
*No necrosis.
* Mean age: 50 years.
* As the name states: A tumour of the cerebellum.
** But cases outside cerebellum reported that would qualify.<ref>{{Cite journal  | last1 = Gupta | first1 = K. | last2 = Salunke | first2 = P. | last3 = Kalra | first3 = I. | last4 = Vasishta | first4 = RK. | title = Central liponeurocytoma: case report and review of literature. | journal = Clin Neuropathol | volume = 30 | issue = 2 | pages = 80-5 | month =  | year =  | doi =  | PMID = 21329617 }}</ref>
* WHO grade II <ref>{{Cite journal  | last1 = Nishimoto | first1 = T. | last2 = Kaya | first2 = B. | title = Cerebellar liponeurocytoma. | journal = Arch Pathol Lab Med | volume = 136 | issue = 8 | pages = 965-9 | month = Aug | year = 2012 | doi = 10.5858/arpa.2011-0337-RS | PMID = 22849747 }}</ref> (upgraded from WHO grade I in 2007)<ref>{{Cite journal  | last1 = Brat | first1 = DJ. | last2 = Parisi | first2 = JE. | last3 = Kleinschmidt-DeMasters | first3 = BK. | last4 = Yachnis | first4 = AT. | last5 = Montine | first5 = TJ. | last6 = Boyer | first6 = PJ. | last7 = Powell | first7 = SZ. | last8 = Prayson | first8 = RA. | last9 = McLendon | first9 = RE. | title = Surgical neuropathology update: a review of changes introduced by the WHO classification of tumours of the central nervous system, 4th edition. | journal = Arch Pathol Lab Med | volume = 132 | issue = 6 | pages = 993-1007 | month = Jun | year = 2008 | doi = 10.1043/1543-2165(2008)132[993:SNUARO]2.0.CO;2 | PMID = 18517285 }}</ref>
*ICD-O code: 9506/1


==Dysembryoplastic neuroepithelial tumour==
====Histo====
*Abbreviated ''DNT''.
* Advanced neuronal and lipomatous differentiation.
* Neurocytes: round to oval nuclei with clear cytoplasm.
* Quite cellular.
* Mitoses almost absent.  


===General===
====IHC====
*Common tumour cause of drug resistant epilepsy.<ref name=pmid15881751>{{Cite journal  | last1 = Cataltepe | first1 = O. | last2 = Turanli | first2 = G. | last3 = Yalnizoglu | first3 = D. | last4 = Topçu | first4 = M. | last5 = Akalan | first5 = N. | title = Surgical management of temporal lobe tumor-related epilepsy in children. | journal = J Neurosurg | volume = 102 | issue = 3 Suppl | pages = 280-7 | month = Apr | year = 2005 | doi = 10.3171/ped.2005.102.3.0280 | PMID = 15881751 }}</ref>
* [[GFAP]] +/-ve (focal).  
*Paediatric population.
* [[MAP2]] +ve.
* Synaptophysin +ve.
* NeuN +ve.
* MIB-1: usu 1-3%.


===Gross/radiology===
====Molecular====
*Temporal lobe.
* Distinct methylation profile.
*Variable architecture:<ref name=pmid18071981/> cystic, solitary nodular, multinodular.
* Recurent losses on 2p and Chr. 14.<ref>{{Cite journal  | last1 = Capper | first1 = D. | last2 = Stichel | first2 = D. | last3 = Sahm | first3 = F. | last4 = Jones | first4 = DTW. | last5 = Schrimpf | first5 = D. | last6 = Sill | first6 = M. | last7 = Schmid | first7 = S. | last8 = Hovestadt | first8 = V. | last9 = Reuss | first9 = DE. | title = Practical implementation of DNA methylation and copy-number-based CNS tumor diagnostics: the Heidelberg experience. | journal = Acta Neuropathol | volume =  | issue =  | pages =  | month = Jul | year = 2018 | doi = 10.1007/s00401-018-1879-y | PMID = 29967940 }}</ref>


===Microscopic===
<gallery>
Features:<ref name=pmid18071981>{{Cite journal  | last1 = O'Brien | first1 = DF. | last2 = Farrell | first2 = M. | last3 = Delanty | first3 = N. | last4 = Traunecker | first4 = H. | last5 = Perrin | first5 = R. | last6 = Smyth | first6 = MD. | last7 = Park | first7 = TS. | title = The Children's Cancer and Leukaemia Group guidelines for the diagnosis and management of dysembryoplastic neuroepithelial tumours. | journal = Br J Neurosurg | volume = 21 | issue = 6 | pages = 539-49 | month = Dec | year = 2007 | doi = 10.1080/02688690701594817 | PMID = 18071981 }}</ref>
File:Cerebellar liponeurocytoma.jpg | Liponeurocytoma, HE (WC/Marvin101).
*Cells similar to oligodendrocytes:
File:Liponeurocytoma Synaptophysin.jpg | Liponeurocytoma, Synapto (WC/Marvin101).
**Large central nuclei with indentations.
File:Cerebellar Liponeurocytoma HE.jpg | Liponeurocytoma, HE (WC/jensflorian).
**Multiple small nucleoli (common).
File:Cerebellar Liponeurocytoma Synaptophysin.jpg | Liponeurocytoma, Synapto (WC/jensflorian).
**Clear cytoplasm.
</gallery>


DDx:
====DDx====
*[[Oligodendroglioma]].
* [[Medulloblastoma]]
**These have rounder, smaller nuclei with occasional nucleoli.<ref name=pmid18071981/>
* [[Neurocytoma]]


Images:
===Gangliocytoma===
*[http://commons.wikimedia.org/wiki/File:DNET_HE.jpg DNT (WC)].
* Grade I WHO neuronal tumour.
*[http://path.upmc.edu/cases/case106.html DNT - several images (upmc.edu)].
** ICD-O code: 9492/0
* Groups of irregular large neurons.
* Non-neoplastic, reticulin-rich glial stroma.


==Subependymal giant cell astrocytoma==
===Ganglioglioma===
*Abbreviated ''SEGA''.
:'''Not''' to be confused with ''[[ganglioneuroma]]''.
 
====General====
===General===
*Gangliolioma: Grade I WHO mixed neuronal-glial tumour (ICD-O code: 9505/1).
*Associated with [[tuberous sclerosis complex]] (TSC).<ref name=pmid21455842>{{Cite journal  | last1 = Grajkowska | first1 = W. | last2 = Kotulska | first2 = K. | last3 = Jurkiewicz | first3 = E. | last4 = Roszkowski | first4 = M. | last5 = Daszkiewicz | first5 = P. | last6 = Jóźwiak | first6 = S. | last7 = Matyja | first7 = E. | title = Subependymal giant cell astrocytomas with atypical histological features mimicking malignant gliomas. | journal = Folia Neuropathol | volume = 49 | issue = 1 | pages = 39-46 | month =  | year = 2011 | doi =  | PMID = 21455842 }}</ref>
*Anaplastic ganglioglioma: Grade III (ICD-O: 9505/3)
*WHO Grade I.
*Rare (approx. 0.5% of all CNS tumors).
 
*Usu. temporal lobe.
===Gross/radiology===
*Predominantly children (mean age: 9 years).
*Well-demarcated.
*Recognized as a cause of [[epilepsy]].<ref name=pmid12125968>{{Cite journal  | last1 = Im | first1 = SH. | last2 = Chung | first2 = CK. | last3 = Cho | first3 = BK. | last4 = Lee | first4 = SK. | title = Supratentorial ganglioglioma and epilepsy: postoperative seizure outcome. | journal = J Neurooncol | volume = 57 | issue = 1 | pages = 59-66 | month = Mar | year = 2002 | doi =  | PMID = 12125968 }}</ref>
 
*Favourable prognosis (survival rates up to 97%)
===Microscopic===
**Insufficient data für anaplastic ganglioglioma.
Features:<ref name=upmc_case179/><ref name=pmid9595853>{{Cite journal  | last1 = Taraszewska | first1 = A. | last2 = Kroh | first2 = H. | last3 = Majchrowski | first3 = A. | title = Subependymal giant cell astrocytoma: clinical, histologic and immunohistochemical characteristic of 3 cases. | journal = Folia Neuropathol | volume = 35 | issue = 3 | pages = 181-6 | month = | year = 1997 | doi =  | PMID = 9595853 }}</ref>
*Giant cells with nuclear atypia ("bizarre cells").
**Vesicular nuclei.
**[[Nuclear pseudoinclusions]].<ref name=upmc179>URL: [http://path.upmc.edu/cases/case179/micro.html http://path.upmc.edu/cases/case179/micro.html]. Accessed on: 8 January 2012.</ref>
*Glassy eosinophilic cytoplasm.
*Abundant [[mast cell]]s.<ref name=upmc179>URL: [http://path.upmc.edu/cases/case179/micro.html http://path.upmc.edu/cases/case179/micro.html]. Accessed on: 8 January 2012.</ref>


Images:
====Macroscopic====
*[http://path.upmc.edu/cases/case179/micro.html SEGA (upmc.edu)].<ref name=upmc_case179>URL: [http://path.upmc.edu/cases/case179.html http://path.upmc.edu/cases/case179.html]. Accessed on: 29 July 2011.</ref>
*Circumscribed lesion.
*Usu. contrast enhancing.
*Solid, but intracortical cysts may be present.
*Little mass effect.


===IHC===
Features:<ref name=pmid9595853/>
*GFAP +ve. (???)
*Vimentin +ve. (???)
*S100 +ve. (???)


==Pilomyxoid astrocytoma==
====Microscopic====
===General===
Features:<ref name=Ref_PSNP86>{{Ref PSNP|86}}</ref>
*A variant of ''pilocytic astrocytoma''.
**Some have suggested it is a unique entity.<ref name=pmid16048293>{{cite journal |author=Komotar RJ, Mocco J, Jones JE, ''et al.'' |title=Pilomyxoid astrocytoma: diagnosis, prognosis, and management |journal=Neurosurg Focus |volume=18 |issue=6A |pages=E7 |year=2005 |month=June |pmid=16048293 |doi= |url=}}</ref>
*Childhood or adolescence.
 
===Gross===
Features:<ref name=Ref_PSNP86>{{Ref PSNP|86}}</ref>
*Classically - hypothalamic location/suprasellar location; may involve the sella turcica.<ref name=pmid19766001>{{cite journal |author=Alimohamadi M, Bidabadi MS, Ayan Z, Ketabchi E, Amirjamshidi A |title=Pilomyxoid astrocytoma with involvement of the sella turcica in an adolescent |journal=J Clin Neurosci |volume=16 |issue=12 |pages=1648–9 |year=2009 |month=December |pmid=19766001 |doi=10.1016/j.jocn.2009.01.035 |url=}}</ref>
*Solid.
*Well-circumscribed.
 
===Microscopic===
Features:<ref name=Ref_PSNP86>{{Ref PSNP|86}}</ref>
*Consists of small round/ovoid bland cells in a myxoid stroma.
*Hair-like fibres ~ 1 micrometer.
**Often difficult to appreciate on standard (H&E) histologic sections.
*Usually angiocentric (surround blood vessel) - '''key feature'''.
 
Notes:<ref name=Ref_PSNP86>{{Ref PSNP|86}}</ref>
*Rosenthal fibres are absent - '''key negative'''.
*Monophasic (unlike classical pilocytic astrocytomas) - '''key negative'''.
*May rarely have eosinophilic granular bodies.
 
===Grading===
*''WHO Grade II'' by definition.<ref name=Ref_PSNP86>{{Ref PSNP|86}}</ref>
 
==Atypical teratoid/rhabdoid tumour==
:See also: ''[[Extrarenal malignant rhabdoid tumour]]''.
*Commonly abbreviated ''AT/RT''.
*May be written ''atypical teratoid rhabdoid tumour'', i.e. without the forward slash, or ''atypical teratoid-rhabdoid tumour'' (AT-RT).
 
===General===
*Usually supratentorial, occasionally in posterior fossa, case reports of spinal cord.
 
===Microscopic===
Features:
Features:
*Cellular.
*Dysplastic neurons.
*Small round cells usu. with a prominent nucleolus.
**Out of regular architecture / abnormal location.
*Rhabdoid cells.
**Cytomegaly
**Cells with eosinophilic granular cytoplasm + eccentric nucleus. (???)
**Clustering
*Mitoses.
**Binucleated (very occassionally).
*Atypical glia.
*Eosinophilic granular bodies.
*Calcification.
*Prominent capillary network.
*Lymphocytic cuffing.
*May contain some reticulin.  
*Glial component may resemble:
**Fibrillary astrocytoma.
**Oligodendroglioma.
**Pilocytic astrocytoma.


DDx:
Anaplastic ganglioglioma:
*[[Primitive neuroectodermal tumour]] (PNET).
*Brisk mitotic activity
*[[Diffuse astrocytoma]].
*Necrosis
*[[Choroid plexus carcinoma]].
*[[Embryonal carcinoma]].


Images:
====IHC====
*[http://commons.wikimedia.org/wiki/File:Rhabdoidtumourcell.jpg Rhabdoid tumour cell (WC)].
*Neurons:
*[http://commons.wikimedia.org/wiki/File:ATRT-HE-Overview.jpg AT/RT (WC)].
**[[MAP2]] +ve
*[http://commons.wikimedia.org/wiki/File:ATRT-INI1.jpg AT/RT -ve for INI1 (WC)].
**Synaptophysin +ve
*[http://path.upmc.edu/cases/case99/micro.html AR/RT (upmc.edu)].
** Neurofilament +ve
*Glia:
**CD34+/-ve
*BRAF V600E +ve (approx. 25%, mainly ganglion cells).


===IHC===
====Molecular====
*BAF-47 -ve ([[AKA]] ''INI1'', [[AKA]] ''SMARCB1'' - the HGNC symbol<ref name=omim601607>{{OMIM|601607}}</ref>) - virtually diagnostic.
*BRAF V600E-mutated(approx. 25%).
**Endothelial cells +ve control.
*IDH1/2 wt.
*S-100 +ve.
*No 1p/19q codeletion.
**Few other brain tumours express it.
*Usu. Chr. 7 gain.  
*Vimentin +ve (perinuclear condensation).
*CDKN2A deletions in anaplastic ganglioglioma.  


Others:
====DDx:====
*GFAP +ve (focal - in tumour cells).
*[[DNT]].
*EMA +ve (patchy cytoplasmic).
*[[Oligodendroglioma]].
*Smooth muscle actin +ve.
*Trapped cortical neurons in diffuse astrocytoma.
*Papillary glioneuronal tumor.
*Dysembryoplastic neuroepithelial tumor.


==Oligodendroglioma==
====Images====
===General===
<gallery>
*Do ''not'' arise from oligodendrocytes.
File:Ganglioglioma lymphocytic cuffing PAS.jpg | Lymphocytic cuffing in ganglioglioma (WC/jensflorian)
**Arise from ''glial precursor cells''.
File:Ganglioglioma calcification.jpg | Calcification in ganglioglioma (WC/jensflorian)
File:Ganglioglioma Cd34 x200.jpg | CD34 immunostain in ganglioglioma (WC/jensflorian)
File:Anaplastic ganglioglioma HE.jpg | Pleomorphic ganglion cells in ganglioglioma (WC/jensflorian)
</gallery>
*[http://path.upmc.edu/cases/case142.html Ganglioglioma - case 1 (upmc.edu)].
*[http://path.upmc.edu/cases/case282.html Ganglioglioma - case 2 (upmc.edu)].


Usual location:
===Lhermitte-Duclos disease===
*Fourth ventricle.
*Abbreviated ''LDD''.
*Intramedullary spinal cord.
*[[AKA]] ''dysplastic cerebellar gangliocytoma''.<ref name=pmid20060133>{{Cite journal  | last1 = Yağci-Küpeli | first1 = B. | last2 = Oguz | first2 = KK. | last3 = Bilen | first3 = MA. | last4 = Yalçin | first4 = B. | last5 = Akalan | first5 = N. | last6 = Büyükpamukçu | first6 = M. | title = An unusual cause of posterior fossa mass: Lhermitte-Duclos disease. | journal = J Neurol Sci | volume = 290 | issue = 1-2 | pages = 138-41 | month = Mar | year = 2010 | doi = 10.1016/j.jns.2009.12.010 | PMID = 20060133 }}</ref>
*[[AKA]] ''dysplastic gangliocytoma of the cerebellum''.
{{Main|Lhermitte-Duclos disease}}
<gallery>
File:Dysplastic_gangliocytoma_lhermitte_duclos.jpg | Dysplastic gangliocytoma (low mag).
</gallery>


Prognosis by flavours (average survival):<ref name=Ref_PSNP98>{{Ref PSNP|98}}</ref>
===Papillary glioneuronal tumour===
*WHO grade II: 10-15 years.
* Abbreviated ''PGNT''.
*WHO grade III: 3-5 years.
* A benign, supratentorial tumor of childhood.
** Biologic course corresponds to WHO grade I.
** Before WHO 2000, considered a [[Ganglioglioma]] variant.
*Prominent pseudopapillary architecture.
*Neurocytes to medium-sized ganglion cells.
*GFAP+ core, GFAP- layer
*Rosenthal fibers, Eosinophilic Granular bodies and lymphocytic cuffing may be present.
<gallery>
File:PGNT_HE_stain.jpg | PGNT (HE) (WC/jensflorian)
</gallery>


===Microscopic===
===Rosette-forming glioneuronal tumour of the fourth ventricle===
Features:
* Abbreviated ''RGNT''.
*Highly cellular lesion composed of:
* Provisional ICD-O code: 9509/1
**Cells resembling ''fried eggs'' (oligodendrocytes) with:
* A rare benign infratentorial tumour of the midline of children and adults.  
***Round nucleus - '''key feature'''.
* Biologic course corresponds to WHO grade I.
***Distinct cell borders.
* Glial component corresponds to [[pilocytic astrocytoma]].
***Moderate-to-marked nuclear atypia.
* Neurocytic rosettes.
***Clear cytoplasm - useful feature (if present).
* Eosinopil fibrillary cores / pseudorosettes.
****Some oligodendrogliomas have eosinophilic cytoplasm with focal perinuclear clearing.
* GFAP+ in fibrillary areas, Syn+ in rosettes.
**Acutely branched capillary sized vessels - "chicken-wire" like appearance.
* Neurocytic cells: MAP2+
***Abundant, delicate appearing; may vaguely resemble a paraganglioma at low power.
* MIB-1 usu. below 3%.
*Calcifications - important feature.<ref>URL: [http://www.emedicine.com/radio/topic481.htm http://www.emedicine.com/radio/topic481.htm].</ref>
<gallery>
File:Histology RGNT HE.jpg | RGNT, HE stain (WC/jensflorian).
File:RGNT HE 2.jpg | RGNT, higher magnification (WC/jensflorian).
</gallery>


DDx:
===Polymorphous low-grade tumor of the young (PLNTY)===
*[[Neurocytoma]] also have perinuclear clearing and well-defined cellular borders.
* [[Pediatric-type diffuse low-grade glioma#Diffuse low-grade glioma, MAPK pathway-altered|Polymorphous low-grade tumor of the young (PLNTY)]]
**Pineocytomatous/neurocytic rosettes = (irregular) rosette with a large meshwork of fibers (neuropil) at the centre.
 
Notes:
*Few neural tumours have round nuclei - DDx:
**[[Oligodendroglioma]].
**[[Lymphoma]].
**Clear cell variant of [[ependymoma]].
**[[Germ cell tumour]] (germinoma/dysgerminoma/seminoma).
 
Images:
*[http://commons.wikimedia.org/wiki/File:Oligodendroglioma1_high_mag.jpg Oligodendroglioma high mag. (WC)].
*[http://commons.wikimedia.org/wiki/File:Oligodendroglioma1_low_mag.jpg Oligodendroglioma low mag. (WC)].
 
====Histologic grading====
Come in two flavours:
# WHO grade II.
#*This is most oligodendrogliomas.
# WHO grade III.
#*Features for calling high grade:<ref name=Ref_PSNP98>{{Ref PSNP|98}}</ref>
#**Endothelial hypertrophy.
#***Plump/large endothelial cells.
#**Necrosis.
#**High mitotic rate (6 mitoses/10 HPF for whatever "HPF" means, see [[HPFitis]]).
 
===IHC===
Features:
*MAP-2 +ve.<reF name=pmid12025943>{{cite journal |author=Suzuki SO, Kitai R, Llena J, Lee SC, Goldman JE, Shafit-Zagardo B |title=MAP-2e, a novel MAP-2 isoform, is expressed in gliomas and delineates tumor architecture and patterns of infiltration |journal=J. Neuropathol. Exp. Neurol. |volume=61 |issue=5 |pages=403–12 |year=2002 |month=May |pmid=12025943 |doi= |url=}}</ref>
*GFAP -ve.
**Some subtypes +ve - should not be used to distinguish.<ref name=Ref_PSNP>{{Ref PSNP|98}}</ref>
*EMA +ve.
*IDH-1 -ve. (???).
*p53 -ve.
**Useful for differentiating ''astrocytoma'' vs. ''oligodendroglioma''.
*Ki-67.


===Molecular pathology===
==Pineal tumours==
Losses of 1p and 19q both helps with diagnosis and is prognostic:<ref name=pmid18565359>{{cite journal |author=Fontaine D, Vandenbos F, Lebrun C, Paquis V, Frenay M |title=[Diagnostic and prognostic values of 1p and 19q deletions in adult gliomas: critical review of the literature and implications in daily clinical practice] |language=French |journal=Rev. Neurol. (Paris) |volume=164 |issue=6-7 |pages=595–604 |year=2008 |pmid=18565359 |doi=10.1016/j.neurol.2008.04.002 |url=}}</ref>
{{Main|Pineal gland}}
*Greater chemosensitivity
*Better prognosis.


==Oligoastrocytoma==
* [[Pineocytoma]]
===General===
* [[Pineal parenchymal tumour of intermediate differentiation]]
*Mixed tumour.
* [[Pineoblastoma]]
* [[Papillary tumour of the pineal region]]


===Microscopic===
==Embryonal tumours==
Features:
* [[Atypical teratoid/rhabdoid tumour]] (AT/RT) or (AT-RT)
*Astrocytoma-like and oligodendroglioma-like:
* [[Medulloblastoma]]
*#Oligodendroglioma-like cells = round nucleus, peri-nuclear clearing.
* [[Primitive neuroectodermal tumour]] (PNET)
*#Astrocytoma-like cells = non-ovoid/elongated nucleus.
* [[Embryonal tumour with abundant neuropil and true rosettes]] (ETANTR)


DDx:
DDx:
*Anaplastic astrocytoma.
* [[Ewing sarcoma]]
*Oligodendroglioma. (???)
* [[Sarcoma with CIC-rearrangement]]
 
===IHC===
*Oligodendroglioma-like cells: MAP-2 +ve (cytoplasm).
*Astrocytoma-like cells: GFAP +ve (cytoplasm, nuclear membrane).
 
Others:
*Ki-67 ~10%. (???)
*p53 - focally +ve. (???)
*IDH-1 -ve. (???)
 
==Meningioma==
{{Main|Meningioma}}
===General===
*Very common.
*May be part of a syndrome.
 
===Microscopic===
Features (memory device ''WCN''):
*Whorled appearance - '''key feature'''.
*Calcification, psammomatous.
*[[Nuclear pseudoinclusions]] - focal nuclear clearing with a sharp interface to unremarkable chromatin.
 
Grading: see ''[[meningioma]]''.


==Peripheral nerve sheath tumours==
==Peripheral nerve sheath tumours==
{{Main|Peripheral nerve sheath tumours}}
{{Main|Peripheral nerve sheath tumours}}
A classification:<ref name=pmid17893219>{{cite journal |author=Wippold FJ, Lubner M, Perrin RJ, Lämmle M, Perry A |title=Neuropathology for the neuroradiologist: Antoni A and Antoni B tissue patterns |journal=AJNR Am J Neuroradiol |volume=28 |issue=9 |pages=1633–8 |year=2007 |month=October |pmid=17893219 |doi=10.3174/ajnr.A0682 |url=http://www.ajnr.org/cgi/reprint/28/9/1633}}</ref>
A classification:<ref name=pmid17893219>{{cite journal |author=Wippold FJ, Lubner M, Perrin RJ, Lämmle M, Perry A |title=Neuropathology for the neuroradiologist: Antoni A and Antoni B tissue patterns |journal=AJNR Am J Neuroradiol |volume=28 |issue=9 |pages=1633–8 |year=2007 |month=October |pmid=17893219 |doi=10.3174/ajnr.A0682 |url=http://www.ajnr.org/cgi/reprint/28/9/1633}}</ref>
*Benign:
'''Benign:'''
**[[Schwannoma]].
*[[Schwannoma]].
**[[Neurofibroma]].
*[[Neurofibroma]].
**[[Perineurioma]].
*[[Perineurioma]].
*Ganglioneuroma.
**[[Traumatic neuroma]].
**[[Traumatic neuroma]].
*Malignant:
'''Malignant:'''
**[[Malignant peripheral nerve sheath tumour]] (MPNST).
*[[Malignant peripheral nerve sheath tumour]] (MPNST).
 
==Schwannoma==
 
{{Main|Schwannoma}}
===General===
*Tumour of tissue surrounding a nerve.
**Axons adjacent to the tumour are normal... but may be compressed.
 
===Microscopic===
Features:<ref name=pmid17893219>{{cite journal |author=Wippold FJ, Lubner M, Perrin RJ, Lämmle M, Perry A |title=Neuropathology for the neuroradiologist: Antoni A and Antoni B tissue patterns |journal=AJNR Am J Neuroradiol |volume=28 |issue=9 |pages=1633–8 |year=2007 |month=October |pmid=17893219 |doi=10.3174/ajnr.A0682 |url=http://www.ajnr.org/cgi/reprint/28/9/1633}}</ref>
*Antoni A:
**Cellular.
**'Fibrillary, polar, elongated'.
*Antoni B:
**Pauci-cellular.
**Loose microcystic tissue.
*Verocay bodies - paucinuclear area surrounded by palisaded nuclei.
*In the GI tract: classically have a ''peripheral lymphoid cuff''.<ref name=pmid15728600>{{cite journal |author=Levy AD, Quiles AM, Miettinen M, Sobin LH |title=Gastrointestinal schwannomas: CT features with clinicopathologic correlation |journal=AJR Am J Roentgenol |volume=184 |issue=3 |pages=797–802 |year=2005 |month=March |pmid=15728600 |doi= |url=http://www.ajronline.org/cgi/content/full/184/3/797}}</ref>
 
Images:
*[http://www.pathguy.com/~lulo/lulo0003.htm Antoni A (pathguy.com)].
*[http://www.ajnr.org/cgi/content/full/28/9/1633/F8 Antoni A & Antoni B side-by-side (ajnr.org)].
 
Notes:
*Several subtypes exist.


==Neurofibroma==
===Ganglioneuroma===
{{Main|Peripheral nerve sheath tumours#Neurofibroma}}
:'''Not''' to be confused with ''[[ganglioglioma]]''.
===General===
*May be a part of [[neurofibromatosis]] 1.
*Composed of Schwann cells, axons, fibrous material.<ref name=pmid17893219/>
 
===Microscopic===
Features:
*Spindle cells lesion.
**See ''[[Neurofibroma]]'' article for details.
 
Image:
*[http://commons.wikimedia.org/wiki/File:Neurofibroma_(1).jpg Neurofibroma - low mag. (WC)].
*[http://commons.wikimedia.org/wiki/File:Neurofibroma_(2).jpg Neurofibroma - high mag. (WC)].
*[http://commons.wikimedia.org/wiki/File:Neurofibroma_(3).jpg Neurofibroma - high mag. (WC)].
 
==Ganglioneuroma==
===General===
*[[AKA]] ganglioma.<ref>URL: [http://medical-dictionary.thefreedictionary.com/ganglioma http://medical-dictionary.thefreedictionary.com/ganglioma]. Accessed on: 8 November 2010.</ref>
*[[AKA]] ganglioma.<ref>URL: [http://medical-dictionary.thefreedictionary.com/ganglioma http://medical-dictionary.thefreedictionary.com/ganglioma]. Accessed on: 8 November 2010.</ref>
*May be retroperitoneal.
{{Main|Ganglioneuroma}}
*Multiple ganglioneuromas may be due to [[multiple endocrine neoplasia IIb]].


===Microscopic===
Features:
*Ganglion cells - '''key feature'''.
**Large cells with large nucleus.
***Prominent nucleolus.
*Disordered fibrinous-like material.
*Eosinophilic granular bodies.<ref>R. Kiehl. 8 November 2010.</ref>


Images:
*[http://it.wikipedia.org/wiki/File:Ganglioneuroma_(1).jpg Ganglioneuroma (WC)].
*[http://www.webpathology.com/image.asp?n=4&Case=84 Ganglioneuroma (webpathology.com)].
*[http://en.wikipedia.org/wiki/File:Ganglion_high_mag.jpg Normal ganglion - high mag. (WC)] .


See: ''[[Adrenal gland]]''.
==Meningioma==
 
{{Main|Meningioma}}
==Ependymoma==
===General===
*Called the forgotten glial tumour.
 
Epidemiology:<ref name=Ref_PBoD8_1334>{{Ref PBoD8|1334}}</ref>
*Usual site:
**Adults: usu. spinal cord.
**Children: usu. posterior fossa.
*May be assoc. with [[neurofibromatosis]] 2.
 
Comes in two main flavours:
#Ependymoma (not otherwise specified).
#Myxopapillary ependymoma.
#*Classically at filum terminale.
 
Other flavours:<ref>URL: [http://emedicine.medscape.com/article/1744030-overview http://emedicine.medscape.com/article/1744030-overview]. Accessed on: 17 January 2012.</ref>
*Papillary ependymoma.
*Clear cell ependymoma.
 
===Microscopic===
====Classic ependymoma====
Features:
*Cells have a "tadpole-like" morphology.
**May also be described as ''ice cream cone-shaped''.<ref>[http://www.pathology.vcu.edu/WirSelfInst/tumor-2.html http://www.pathology.vcu.edu/WirSelfInst/tumor-2.html]</ref>
*'''Rosettes''' = circular nuclear free zones/cells arranged in a pseudoglandular fashion; comes in two flavours in ependymoma:
**''Perivascular pseudorosettes'' = (tumour) cells arranged around a blood vessel; nuclei of cells distant from the blood vessel, i.e. rim of cytoplasm (from tumour cells) surround blood vessel (nucleus-free zone); more common than ependymal rosette... but less specific.
**''Ependymal rosette'' ([[AKA]] ''true ependymal rosette'') = rosette has an empty space at the centre - '''key feature'''.
*Nuclear features monotonous, i.e. "boring".<ref>MUN. 6 Oct 2009.</ref>
**There is little variation in size, shape and staining.
 
DDx (classic ependymoma):
*[[Subependymoma]].
*[[Glioblastoma]] (GBM).
**Invasive border = GBM; circumscribed border of lesion = ependymoma.
 
Images:
*www:
**[http://www.flickr.com/photos/ckrishnan/3862487821/in/photostream Ependymoma (flickr.com)].
**[http://www.ajnr.org/cgi/content-nw/full/27/3/488/F10 Ependymoma - ependymal rosettes (ajnr.org)].
**[http://path.upmc.edu/cases/case95/micro.html Anaplastic ependymoma - case 1 (upmc.edu)].
**[http://path.upmc.edu/cases/case324.html Anaplastic ependymoma - case 2 (upmc.edu)].
*WC:
**[http://commons.wikimedia.org/wiki/File:Ependymoma_intermed_mag.jpg Ependymoma - intermed. mag. (WC)].
**[http://commons.wikimedia.org/wiki/File:Ependymoma_low_intermed_mag.jpg Ependymoma - low mag. (WC)].
 
====Myxopapillary ependymoma====
Features:
*Perivascular pseudorosettes:
**Myxoid material surround blood vessels.
***Myxoid material surrounded by tumour cells.
 
Images:
*[http://commons.wikimedia.org/wiki/File:Myxopapillary_ependymoma_-_high_mag.jpg Myxopapillary ependymoma - high mag. (WC)].
*[http://careers.bmj.com/article-images/cf0708.f2_default.gif Myxopapillary ependymoma (bmj.com)] - part of [http://careers.bmj.com/careers/advice/view-article.html?id=351 careers.bmj.com article on paediatric pathology].
*[http://commons.wikimedia.org/wiki/File:Myxopapillary_ependymoma.jpg Myxopapillary ependymoma - cytology (WC)].
 
====Grading====
Easy:
*Subependymoma = WHO grade I.
*Myxopapillary ependymoma = WHO grade I.
Not-so-easy:
*Classic ependymoma = WHO grade II.
*Anaplastic ependymoma = WHO grade III.
 
Grade II vs. Grade III:
*Cellular density.
*Mitoses.
*Necrosis.
*Microvascular proliferation.
 
Notes:
*Many tumours fall between grade II and grade III.  These are called "indeterminate" by many.
 
===IHC===
*Reticulin.
*GFAP.
*MIB-1.
 
==Subependymoma==
===General===
*Good prognosis - WHO Grade I.
 
===Gross/radiology===
*Classic location: fourth ventricle.<ref>{{Cite journal  | last1 = Hoeffel | first1 = C. | last2 = Boukobza | first2 = M. | last3 = Polivka | first3 = M. | last4 = Lot | first4 = G. | last5 = Guichard | first5 = JP. | last6 = Lafitte | first6 = F. | last7 = Reizine | first7 = D. | last8 = Merland | first8 = JJ. | title = MR manifestations of subependymomas. | journal = AJNR Am J Neuroradiol | volume = 16 | issue = 10 | pages = 2121-9 | month =  | year =  | doi =  | PMID = 8585504 |url=http://www.ajnr.org/cgi/reprint/16/10/2121}}</ref>
*Well demarcated margin.
*Usu. completely within the ventricle; does not extend into brain (like [[ependymoma]]s).
 
===Microscopic===
Features:<ref name=ouhsc>URL: [http://moon.ouhsc.edu/kfung/jty1/Com05/Com501-2-Diss.htm http://moon.ouhsc.edu/kfung/jty1/Com05/Com501-2-Diss.htm]. Accessed on: 2 June 2011.</ref>
*Microcysts with bluish material - give a spongy appearance at low magnification.
*Nuclei cluster.
**Described as "bundles of flowers".
 
Negatives.
*No nuclear pleomorphism, no prominent nucleoli, no mitoses.
 
Images:
*[http://moon.ouhsc.edu/kfung/jty1/Com05/Com05Image/Com501-2-04.gif Subependymoma (ouhsc.edu)].<ref name=ouhsc>URL: [http://moon.ouhsc.edu/kfung/jty1/Com05/Com501-2-Diss.htm http://moon.ouhsc.edu/kfung/jty1/Com05/Com501-2-Diss.htm]. Accessed on: 2 June 2011.</ref>
*[http://commons.wikimedia.org/wiki/File:Subependymoma_-_intermed_mag.jpg Subependyoma - intermed. mag. (WC)].
*[http://commons.wikimedia.org/wiki/File:Subependymoma_-_high_mag.jpg Subependymoma - high mag. (WC)].
 
==Choroid plexus papilloma==
===General===
*Benign - WHO grade I.<ref name=pmid20644273>{{Cite journal  | last1 = Menon | first1 = G. | last2 = Nair | first2 = SN. | last3 = Baldawa | first3 = SS. | last4 = Rao | first4 = RB. | last5 = Krishnakumar | first5 = KP. | last6 = Gopalakrishnan | first6 = CV. | title = Choroid plexus tumors: an institutional series of 25 patients. | journal = Neurol India | volume = 58 | issue = 3 | pages = 429-35 | month =  | year =  | doi = 10.4103/0028-3886.66455 | PMID = 20644273 |URL = http://www.neurologyindia.com/article.asp?issn=0028-3886;year=2010;volume=58;issue=3;spage=429;epage=435;aulast=Menon }}</ref>
*Usu. laternal ventricle in kids.<ref>URL: [http://emedicine.medscape.com/article/250795-overview http://emedicine.medscape.com/article/250795-overview]. Accessed on: 3 June 2011.</ref>
 
===Microscopic===
Features:
*Simple epithelium.
*Papillae.
*Psammoma bodies.
 
Image:
*[http://commons.wikimedia.org/wiki/File:Choroid_plexus_papilloma_micrograph.jpg Choroid plexus papilloma (WC)].
 
==Choroid plexus carcinoma==
===General===
*Usually pediatric population.
*Malignant counterpart of ''[[choroid plexus papilloma]]''.<ref name=pmid19679976>{{Cite journal  | last1 = Singh | first1 = A. | last2 = Vermani | first2 = S. | last3 = Shruti | first3 = S. | title = Choroid plexus carcinoma: report of two cases. | journal = Indian J Pathol Microbiol | volume = 52 | issue = 3 | pages = 405-7 | month =  | year =  | doi = 10.4103/0377-4929.55009 | PMID = 19679976 }}</ref>
*Poor prognosis - WHO grade III.<ref name=pmid20644273>{{Cite journal  | last1 = Menon | first1 = G. | last2 = Nair | first2 = SN. | last3 = Baldawa | first3 = SS. | last4 = Rao | first4 = RB. | last5 = Krishnakumar | first5 = KP. | last6 = Gopalakrishnan | first6 = CV. | title = Choroid plexus tumors: an institutional series of 25 patients. | journal = Neurol India | volume = 58 | issue = 3 | pages = 429-35 | month =  | year =  | doi = 10.4103/0028-3886.66455 | PMID = 20644273 |URL = http://www.neurologyindia.com/article.asp?issn=0028-3886;year=2010;volume=58;issue=3;spage=429;epage=435;aulast=Menon }}</ref>
*Classically posterior fossa.
*Intraventricular mass.
 
===Microscopic===
Features:<ref name=pmid19679976/>
*Choroid plexus epithelium with [[nuclear pleomorphism]] & high [[NC ratio]].
*Mitoses.
*Necrosis.
*+/-Brain invasion.
 
DDx:
*[[Choroid plexus papilloma]].
*Atypical plexus papilloma - has features intermediate between ''choroid plexus papilloma'' and ''choroid plexus carcinoma''.<ref name=pmid20644273/>
*[[Atypical teratoid/rhabdoid tumour]].
 
Images:
*[http://path.upmc.edu/cases/case198/micro.html Choroid plexus carcinoma - several images (upmc.edu)].
 
===IHC===
Features:<ref name=pmid20644273/>
*Cytokeratins +ve.
*EMA usu. -ve.
*GFAP -ve (~20% +ve).
*Ki-67 high.
**Useful to diff. from benign counterpart.
*INI1 +ve.


==Chordoma==
==Chordoma==
===General===
{{Main|Chordoma}}
*Location: usually sacrum or clivus.
 
===Microscopic===
Features:<ref name=Ref_DCHH184>{{Ref DCHH|184}}</ref>
*Architecture: islands of cells surrounded by fibrous tissue.
**Also described as "lobulated" architecture; may not be apparent.
*Myxoid background - grey extracellular material, variable amount present.
*Mixed cell population:
*#Abundant eosinophilic cytoplasm.
*#''Physaliphorous cells'' or ''bubble cells'' - '''key feature'''.
*#*Have a very large clear bubble with a sharp border; bubble does not compress nucleus - nucleus may be in bubble.
 
DDx:
*[[Chondrosarcoma]].
 
Images:
*[[WC]]:
**[http://commons.wikimedia.org/wiki/File:Chordoma_-_low_mag.jpg Chordoma - low mag. (WC)].
**[http://commons.wikimedia.org/wiki/File:Chordoma_-_high_mag.jpg Chordoma - high mag. (WC)].
*www:
**[http://library.med.utah.edu/WebPath/COW/COW062.html Chordoma (med.utah.edu)].
**[http://www.ucl.ac.uk/cancer/research-groups/genetics-of-sarcoma/index.htm Chordoma - several images (acl.ac.uk)].
**[http://path.upmc.edu/cases/case64.html Chordoma (upmc.edu)].
**[http://path.upmc.edu/cases/case312/micro.html Chordoma - sacrum - several images (upmc.edu)].
 
===IHC===
Features:<ref>URL: [http://path.upmc.edu/cases/case312/micro.html http://path.upmc.edu/cases/case312/micro.html]. Accessed on: 14 January 2012.</ref>
*S100 +ve.
*AE1/AE3 +ve.
*Brachyury +ve -- '''key stain'''.
**Protein important for axial development, affects notochord development.<ref>URL:[http://www.ncbi.nlm.nih.gov/omim/601397 http://www.ncbi.nlm.nih.gov/omim/601397]. Accessed on: 18 May 2010.</ref>
**''Brachyury'' literally means ''short tail''.<ref>URL: [http://www.jstor.org/pss/86845 http://www.jstor.org/pss/86845]. Accessed on: 18 May 2010.</ref>


==Hemangioblastoma==
==Hemangioblastoma==
===General===
{{Main|Hemangioblastoma}}
*Usually ''cerebellar''.
*Associated with [[von Hippel-Lindau syndrome]].
*WHO grade I.<ref>URL: [http://www.expertconsultbook.com/expertconsult/ob/book.do?method=display&type=bookPage&decorator=none&eid=4-u1.0-B978-1-4160-4580-9..00019-8--sc0155&isbn=978-1-4160-4580-9 http://www.expertconsultbook.com/expertconsult/ob/book.do?method=display&type=bookPage&decorator=none&eid=4-u1.0-B978-1-4160-4580-9..00019-8--sc0155&isbn=978-1-4160-4580-9]. Accessed on: 9 December 2010.</ref>
 
===Microscopic===
Features:<ref>URL: [http://emedicine.medscape.com/article/340994-media http://emedicine.medscape.com/article/340994-media]. Accessed on: 23 June 2010.</ref>
*Vascular.
*Polygonal stromal cells with:
**Hyperchromatic nuclei.
**Vacuolar cytoplasm.
 
DDx:
*Metastatic [[clear cell renal cell carcinoma]].
 
Images:
*[[WC]]:
**[http://commons.wikimedia.org/wiki/File:Cerebellar_hemangioblastoma_intermed_mag.jpg Hemangioblastoma - intermed. mag. (WC)].
**[http://commons.wikimedia.org/wiki/File:Cerebellar_hemangioblastoma_high_mag.jpg Hemangioblastoma - high mag. (WC)].
**[http://commons.wikimedia.org/w/index.php?title=File:Hemangioblastoma_-_nse_-_intermed_mag.jpg Hemangioblastoma - NSE - intermed. mag. (WC)].
*www:
**[http://path.upmc.edu/cases/case342.html Hemangioblastoma - several images (upmc.edu)].
 
===IHC===
Features:<ref>URL: [http://www.nature.com/modpathol/journal/v18/n6/full/3800351a.html http://www.nature.com/modpathol/journal/v18/n6/full/3800351a.html]. Accessed on: 9 December 2010.</ref>
*Alpha-inhibin +ve (cytoplasm).
*EMA -ve.
**RCC typically +ve.
*NSE +ve (nucleus + cytoplasm).
**RCC typically -ve.
 
==Medulloblastoma==
===General===
*Mostly paediatric population.
*May be seen as a component of [[nevoid basal cell carcinoma syndrome]] (NBCCS).
 
===Gross===
*Location: cerebellum - '''key feature'''.
**Morphologically identical supratentorial tumours are called ''[[primitive neuroectodermal tumour]]'' (PNET).
 
===Microscopic===
Features:<ref>URL: [http://moon.ouhsc.edu/kfung/jty1/neurotest/Q93-Ans.htm http://moon.ouhsc.edu/kfung/jty1/neurotest/Q93-Ans.htm]. Accessed on: 26 October 2010.</ref>
*[[Small round cell tumour]].
*Homer-Wright [[rosette]]s:
**Rosette with a meshwork of fibers (neuropil) at the centre.<ref>{{cite journal |author=Wippold FJ, Perry A |title=Neuropathology for the neuroradiologist: rosettes and pseudorosettes |journal=AJNR Am J Neuroradiol |volume=27 |issue=3 |pages=488–92 |year=2006 |month=March |pmid=16551982 |doi= |url=}}</ref>
 
Image:
*[http://moon.ouhsc.edu/kfung/jty1/neurotest/Q93-Ans.htm Medulloblastoma (ouhsc.edu)].
 
DDx:
*[[Small round cell tumours]].
 
====Subtypes====
*Classic medulloblastoma (~85% of all medulloblastomas).
*Variants of medulloblastoma (~15% of all medulloblastomas together):
*#Anaplastic variant.
*#Large cell variant.
*#Desmoplastic/nodular medulloblastoma (DNMB).
*#Medulloblastoma with extensive nodularity (MBEN).
 
Notes:
*Prognosis:<ref name=pmid18841049>{{cite journal |author=Gulino A, Arcella A, Giangaspero F |title=Pathological and molecular heterogeneity of medulloblastoma |journal=Curr Opin Oncol |volume=20 |issue=6 |pages=668–75 |year=2008 |month=November |pmid=18841049 |doi=10.1097/CCO.0b013e32831369f4 |url=}}</ref><ref name=pmid20940197>{{cite journal |author=Rutkowski S, von Hoff K, Emser A, ''et al.'' |title=Survival and Prognostic Factors of Early Childhood Medulloblastoma: An International Meta-Analysis |journal=J Clin Oncol |volume=28 |issue=33 |pages=4961–4968 |year=2010 |month=November |pmid=20940197 |doi=10.1200/JCO.2010.30.2299 |url=}}</ref> DNMB & MBEN > classic > anaplastic variant, large cell variant.
 
=====Anaplastic variant=====
Features:
*Larger cells.
*Severe anaplasia.
*Polygonal cells.
 
==Primitive neuroectodermal tumour==
*[[AKA]] ''primitive neuroepithelial tumour''. (???)
 
===General===
*Abbreviated ''PNET''.
*Should not be confused with ''peripheral primitive neuroectodermal tumour'' (abbreviated ''[[pPNET]]''<ref name=PST14feb11>PST. 14 February 2011.</ref>), [[AKA]] ''[[Ewing sarcoma]]''.
 
===Microscopic===
Features:
*[[Small round blue cell tumour]] - see ''[[medulloblastoma]]''.
 
DDx: Embryonal tumor with abundant neuropil and true rosettes (ETANTR).<ref>{{cite journal |author=Buccoliero AM, Castiglione F, Degl'Innocenti DR, ''et al.'' |title=Embryonal tumor with abundant neuropil and true rosettes: morphological, immunohistochemical, ultrastructural and molecular study of a case showing features of medulloepithelioma and areas of mesenchymal and epithelial differentiation |journal=Neuropathology |volume=30 |issue=1 |pages=84–91 |year=2010 |month=February |pmid=19563506 |doi=10.1111/j.1440-1789.2009.01040.x |url=}}</ref>
 
Images:
*[http://path.upmc.edu/cases/case414.html Primitive neuroectodermal tumour - several images (upmc.edu)].


==CNS lymphoma==
==CNS lymphoma==
Line 902: Line 614:
*Perivascular clustering.
*Perivascular clustering.


Images:
====Images====
*www:
www:
**[http://frontalcortex.com/?page=image&topic=1&qid=1237 CNS lymphoma (frontalcortex.com)].
*[http://frontalcortex.com/?page=image&topic=1&qid=1237 CNS lymphoma (frontalcortex.com)].
**[http://path.upmc.edu/cases/case403.html Primary CNS lymphoma - several images (upmc.edu)].
*[http://path.upmc.edu/cases/case403.html Primary CNS lymphoma - several images (upmc.edu)].
*[[WC]]:
<gallery>
**[http://commons.wikimedia.org/wiki/File:Primary_CNS_lymphoma_-_high_mag.jpg CNS lymphoma - high mag. (WC)].
Image:Primary CNS lymphoma - low mag.jpg | CNS lymphoma - low mag. (WC)
**[http://commons.wikimedia.org/wiki/File:Primary_CNS_lymphoma_-_low_mag.jpg CNS lymphoma - low mag. (WC)].
Image:Primary CNS lymphoma - intermed mag.jpg | CNS lymphoma - intermed. mag. (WC)
Image:Primary CNS lymphoma - high mag.jpg | CNS lymphoma - high mag. (WC)
Image:Primary CNS lymphoma - very high mag.jpg | CNS lymphoma - very high mag. (WC)
</gallery>
<gallery>
Image: CNS lymphoma (1) B-cell type.jpg | CNS lymphoma. (WC/KGH)
Image: CNS lymphoma (2) B-cell type.jpg | CNS lymphoma. (WC/KGH)
</gallery>


===IHC===
===IHC===
Line 914: Line 633:


Common pattern:
Common pattern:
*CD20 +ve - key stain.
*[[CD20]] +ve - key stain.
*CD3 -ve.
*CD3 -ve.
*Ki-67 ~40%.
*Ki-67 ~40%.
Line 920: Line 639:
*Bcl-1 -ve.
*Bcl-1 -ve.


==Neurocytoma==
===General===
*Rare.
===Microscopic===
Features:<ref>URL: [http://moon.ouhsc.edu/kfung/jty1/Composites/FNA0IE14-Neurocytoma-Micro.htm http://moon.ouhsc.edu/kfung/jty1/Composites/FNA0IE14-Neurocytoma-Micro.htm]. Accessed on: 12 October 2011.</ref>
*[[Pineocytoma|Pineocytomatous]]/neurocytic rosette = irregular rosette with a large meshwork of fibers (neuropil) at the centre.<ref name=pmid16551982>{{cite journal |author=Wippold FJ, Perry A |title=Neuropathology for the neuroradiologist: rosettes and pseudorosettes |journal=AJNR Am J Neuroradiol |volume=27 |issue=3 |pages=488–92 |year=2006 |month=March |pmid=16551982 |doi= |url=}}</ref>
**Similar to Homer-Wright rosette.
*Perinuclear clearing.
*Well-defined cell borders.
DDx:
*[[Oligodendroglioma]] - do not have the characteristic rosettes.
*[[Ganglioglioma]].
*[[Ependymoma]].
Images:
*[http://moon.ouhsc.edu/kfung/jty1/Composites/FNA0IE14-Neurocytoma-Micro.htm Neurocytoma (ouhsc.edu)].
*[http://path.upmc.edu/cases/case383.html Neurocytoma - several images (upmc.edu)].
===IHC===
*Syaptophysin +ve.
**Most glial tumour -ve.<ref>URL: [http://path.upmc.edu/cases/case383/dx.html http://path.upmc.edu/cases/case383/dx.html]. Accessed on: 15 January 2012.</ref>
==Central neurocytoma==
===General===
*Rare.
===Gross/radiology===
*Intraventricular.<ref>URL: [http://moon.ouhsc.edu/kfung/jty1/Com/Com307-1-Diss.htm http://moon.ouhsc.edu/kfung/jty1/Com/Com307-1-Diss.htm]. Accessed on: 12 January 2012.</ref>
===Microscopic===
Features:<ref>URL: [http://moon.ouhsc.edu/kfung/jty1/Com/Com307-1-Diss.htm http://moon.ouhsc.edu/kfung/jty1/Com/Com307-1-Diss.htm]. Accessed on: 27 May 2011.</ref>
*Perivascular pseudorosette = circular/flower-like arrangement of cells with blood vessel at the centre.<ref name=pmid16551982>{{cite journal |author=Wippold FJ, Perry A |title=Neuropathology for the neuroradiologist: rosettes and pseudorosettes |journal=AJNR Am J Neuroradiol |volume=27 |issue=3 |pages=488–92 |year=2006 |month=March |pmid=16551982 |doi= |url=}}</ref>
*Islands of neuropil.
*Polygonal cells with a perinuclear halo.
DDx:
*[[Oligodendroglioma]].


DDx of perivascular pseudorosette:
*Ependymoma.
*[[Medulloblastoma]], PNET.
*[[Glioblastoma]]s.


Images:
==Ganglioneuroblastoma==
*[http://moon.ouhsc.edu/kfung/jty1/Com/Com307-1-Diss.htm Central neurocytoma - several images (ouhsc.edu)].
{{Main|Neuroblastoma}}
*[http://frontalcortex.com/?page=image&topic=1&qid=1203 Central neurocytoma (frontalcortex.com)].
*[http://path.upmc.edu/cases/case74/micro.html Central neurocytoma - crappy images (upmc.edu)].
 
==Ganglioglioma==
:'''Not''' to be confused with ''[[ganglioneuroma]]''.
===General===
===General===
*Rare.
*Uncommon.
*Usu. temporal lobe.
*Part of the ''neuroblastic tumours'' group which includes:<ref name=pmid10421272>{{cite journal |author=Shimada H, Ambros IM, Dehner LP, Hata J, Joshi VV, Roald B |title=Terminology and morphologic criteria of neuroblastic tumors: recommendations by the International Neuroblastoma Pathology Committee |journal=Cancer |volume=86 |issue=2 |pages=349–63 |year=1999 |month=July |pmid=10421272 |doi= |url=}}</ref>
*Recognized as a cause of [[epilepsy]].<ref name=pmid12125968>{{Cite journal | last1 = Im | first1 = SH. | last2 = Chung | first2 = CK. | last3 = Cho | first3 = BK. | last4 = Lee | first4 = SK. | title = Supratentorial ganglioglioma and epilepsy: postoperative seizure outcome. | journal = J Neurooncol | volume = 57 | issue = 1 | pages = 59-66 | month = Mar | year = 2002 | doi = | PMID = 12125968 }}</ref>
**[[Ganglioneuroma]] (benign).
**Ganglioneuroblastoma (intermediate).
**[[Neuroblastoma]] (aggressive).


===Microscopic===
===Microscopic===
Features:
Features:
*Atypical neurons.
*Ganglion-like cells with a prominent nucleolus.
*Atypical glia.
*Small undifferentiated cells with scant cytoplasm.
<gallery>
Image:Adrenal Ganglioneuroblastoma LP CTR.jpg|thumb|Adrenal Ganglioneuroblastoma  - Low power (SKB)
Image:Adrenal Ganglioneuroblastoma MP CTR.jpg|thumb|Adrenal Ganglioneuroblastoma  - Medium power (SKB)
Image:Adrenal Ganglioneuroblastoma HP CTR.jpg|thumb|Adrenal Ganglioneuroblastoma - High power (SKB)
Image:Adrenal Ganglioneuroblastoma HP3 CTR.jpg|thumb|Adrenal Ganglioneuroblastoma - High power (SKB)
Image:Adrenal Ganglioneuroblastoma HP2 CTR.jpg|thumb|Adrenal Ganglioneuroblastoma  - High power (SKB)
</gallery>
Images:
*[http://path.upmc.edu/cases/case530.html Ganglioneuroblastoma - several images (upmc.edu)].


Images:
===IHC===
*[http://path.upmc.edu/cases/case142.html Ganglioglioma - case 1 (upmc.edu)].
*NSE +ve -- small cells.
*[http://path.upmc.edu/cases/case282.html Ganglioglioma - case 2 (upmc.edu)].


==Lesions of the sella turcica==
==Lesions of the sella turcica==

Latest revision as of 09:04, 14 April 2022

A brain stem astrocytoma. (WC)

The article covers tumours in neuropathology. Tumours are a large part of neuropathology. Cytopathology of CNS tumours is dealt with in the article CNS cytopathology.

There are separate articles for peripheral nerve sheath tumours and pituitary/peri-pituitary lesions.

Brain tumours - overview

Alphabetical

For overview see here

By age group

Adult

Four most common types of brain tumours:[1]

  1. Metastatic brain tumours (barely edges out primary tumours)
  2. Glioblastoma, IDH-wildtype.
  3. Astrocytoma, IDH-mutant.
  4. Meningioma.

Children

  1. Pilocytic astrocytoma.
  2. Medulloblastoma.
  3. Ependymoma.
  4. Pontine glioma, often Diffuse midline glioma, H3 K27-altered.

By location

Certain tumours like to hang-out at certain places:[2]

Cerebrum

Cerebellum

Sella turcica

less common:

Spinal cord

Filum terminale

Meninges

less common:

  • Melanoma / Melanocytoma.
  • Lymphoproliferative diseases.
  • Sarcoidosis
  • Arachnoid cyst.
  • Disseminated oligodendroglial-like leptomeningeal tumour.
  • Desmoplastic infantile astrocytoma / ganglioglioma.
  • Meningioangiomatosis.
  • Calcifying pseudoneoplasm.

Skull

Skull base / Cerebellopontine angle

less common:

Primary versus secondary

  • AKA (primary) brain tumour versus metastatic cancer.

Primary

Glial tumours:

  • Cytoplasmic processes - key feature.
    • Best seen at highest magnification - usu. ~1 micrometer.
    • Processes may branch.
  • Ill-defined border/blend with the surrounding brain.

Meningioma:

  • Lesion often dura-based.
  • Mesenchymal tumor (often contains collagen).

Lymphoma:

  • Primary CNS Lymphoma (PCNSL) is usu. a diffuse large B-cell lymphoma.
  • Large (lymphoid) cells, ergo usu. not a difficult diagnosis.
    • ~2x size of resting lymphocyte, nucleoli.
  • Lesion predominantly perivascular.

Secondary

  • Carcinomas:
    • Well-demarcated border between brain and lesion - key feature.
    • No cytoplasmic processes.
    • Usu. have nuclear atypia of malignancy.
    • Nuclei often ~3-4x the size of a RBC.
    • +/-Glandular arrangement.
    • +/-Nucleoli.
  • Melanoma.
  • Secondary Lymphoma.
  • Sarcomas (rare).

By growth pattern

Infiltrative astrocytomas

Notes:

    • Glial: "blends into brain"/gradual transition to non-tumour brain.

Non-infiltrative astrocytomas

Cystic tumours

DDx:[3]


Notes:

    • Non-glial: no radiating glial processes.
  • Rosenthal fibres within the tumour... often seen in pilocytic astrocytoma.
    • Rosenthal fibres may be seen around a (very) slow growing tumour and represent a reactive process.
  • Inflammatory cells and macrophages should prompt consideration of an alternate diagnosis (e.g. cerebral infarct, multiple sclerosis) - esp. if this is a primary lesion.[5]

Grading

Nuclear pleomorphism present:

  • At least grade II (diffuse astrocytoma).

Mitotic figures present:

  • At least grade III (anaplastic astrocytoma).

Microvascular proliferation or necrosis with pseudopalisading tumour cells:

  • Grade IV (glioblastoma AKA glioblastoma multiforme).

Notes:

  • Pseudopalisading tumour cells = high tumour cell density adjacent to regions of necrosis; palisade = a fence of poles forming a defensive barrier or fortification.
  • WHO Grading is currently based on expected biologiocal behaviour without treatment.
    • Grading does not reflect molecular divergent groups within a tumor class or response to therapy (Currently controversies in grading for IDH-mutant astrocytoma vs. IDH-wildtype astrocytoma).[6]

By IHC

Common neuropathology tumours in a table

Type Key feature(s) Imaging History Notes IHC Images
Normal tissue cells regularly spaced, no nuc. atypia small lesion? / deep lesion? variable missed lesion? nil
Normal. (WC)
Reactive astrocytes astrocytes with well-demarcated eosinophilic cytoplasm, regular spacing, no nuc. atypia small lesion? / deep lesion? variable missed lesion / close to a lesion; non-specific pathologic process - need more tissue GFAP
Reactive astrocytes. (WC)
Schwannoma cellular areas (Antoni A), paucicelluar areas (Antoni B), palisading of nuclei (Verocay bodies) extra-axial + intradural old or young need frozen section to Dx, DDx: meningioma S100, SOX10
Schwannoma. (WC)
Meningioma whorls, psammomatous calcs, nuclear inclusions extra-axial + intradural old or young may be diagnosed on smear, DDx: schwannoma, choroid plexus EMA, PR, Ki-67
Meningioma. (WC)
Astrocytoma, IDH-mutant (CNS WHO grade 2 or grade 3) glial processes (esp. on smear), nuclear atypia (typical size var. ~3x, irreg. nuc. membrane, hyperchromasia), no Rosenthal fibres in the core of the lesion †, no microvascular proliferation, no necrosis often enhancing (suggests high grade), usu. supratentorial, usu. white matter usu. old, occ. young common IDH-1(R132H)+/-, GFAP+
High-grade astrocytoma. (WC)
Glioblastoma, IDH-wildtype (CNS WHO grade 4) glial processes (esp. on smear), nuclear atypia (typical size var. ~3x, irreg. nuc. membrane, hyperchromasia), no Rosenthal fibres in the core of the lesion †, microvascular proliferation or necrosis often enhancing (suggests high grade), usu. supratentorial, usu. white matter usu. old, occ. young very common, esp. glioblastoma IDH-1+/-, GFAP+
Glioblastoma. (WC)
Metastasis sharp interface with brain, often glandular, +/-nucleoli, no glial processes often cerebellular, well-circumscribed usu. old often suspected to have metastatic disease TTF-1, CK7, CK20, BRST-2
Metastasis. (WC)

† Rosenthal fibres at the periphery of a lesion are a non-specific finding seen in chronic processes.

Brain metastasis

Main article: Brain metastasis


Molecular

See also: Molecular Neuropathology

Gliomas

Main article: Glioma

Gliomas, glioneuronal tumours and neuronal tumours are often categorized together.

Astrocytic tumours

Main article: Astrocytoma

Features:[9][10]

  • Glial processes - key feature.
    • Thin stringy cytoplasmic processes - best seen at high power in less cellular areas.
  • No Rosenthal fibres within the tumour itself.

Images:

Depreceated:

Oligodendroglial tumours

Depreceated:

Pediatric-type diffuse high-grade glioma

Main article: Pediatric-type diffuse high-grade glioma

Pediatric-type diffuse low-grade glioma

Main article: Pediatric-type diffuse low-grade glioma


Circumscribed astrocytic gliomas

Astroblastoma

  • No WHO grade yet.[11]
  • Very rare superficial tumor of young age.[12]
  • Large, cystic. Pushing margin towards CNS.
  • Vasocentric growth, plump cells with absence of fibrillary pattern.
  • GFAP+ve, Synaptohysin-ve, Olig-2-ve, focally EMA/panCK+ve. MIB-1: 1-18 %.
  • Molecular profile overlaps with classical CNS-PNET.
    • Gene fusions invoving meningioma gene (MN1)[13]


  • HE. (WC/jensflorian)

  • HE. (WC/jensflorian)

  • Astroblastoma (AFIP)

Chordoid glioma of the third ventricle

  • WHO grade II.
  • Slowly growing, non-invasive, in adults.
  • Clusters of epithelioid cells in mucinous stroma.
  • Lymphocytic infiltrates, adjacent Rosenthal fibers.
  • Fibrosis may be present.
  • Few mitoses.
  • GFAP+ve, MIB-1 1-3%.
  • TTF-1+ve.
  • CD34+ve.
  • IDH-1-ve, p53-ve.
  • PRKCA D463H mutations.[14]

  • Chordoid Glioma. (WC/jensflorian)


Ependymal tumours

Choroid plexus tumours

Other neuroepithelial tumours


Cribiform neuroepithelial tumour

AKA: CRINET.

  • Not listed in the current WHO classification.
  • First description in 2009.[15]
  • Around ventricles.[16]
  • Young children.[17]
  • Small undifferentiated cells arranged in cribriform strands and trabeculae of varying thickness.
  • MAP2+ve, Synaptophysin+ve, CK+/-ve. MIB-1: 30%.
  • INI-1 loss, but no rhabdoid features and good prognosis.
  • Stable genomic profile.[18]

Neuronal and mixed neuronal/glial tumours

Desmoplastic infantile astrocytoma / Desmoplastic infantile ganglioglioma

  • Abbreviated DIA or DIG.
  • ICD-O code: 9412/1
  • Large, superficial, cystic tumor of the infancy.
  • Biologic course corresponds to WHO grade I.
  • Very rare, included in the WHO since 1993.
  • Prominent desmoplastic stroma.
  • Astrocytic cells within stroma.
    • GFAP+.
    • MIB-1 usu. 1%.
  • Frequent BRAF V600E or V600D mutations.[19]
  • Single case with BRAF indel or BRAF fusion.

  • Histopathology of DIG (HE stain)

  • Prominent ganglioid cells in DIG (HE stain)

Cerebellar liponeurocytoma

  • Previously called lipomatous medulloblastoma (name changed in WHO 2000).
  • Mean age: 50 years.
  • As the name states: A tumour of the cerebellum.
    • But cases outside cerebellum reported that would qualify.[20]
  • WHO grade II [21] (upgraded from WHO grade I in 2007)[22]
  • ICD-O code: 9506/1

Histo

  • Advanced neuronal and lipomatous differentiation.
  • Neurocytes: round to oval nuclei with clear cytoplasm.
  • Quite cellular.
  • Mitoses almost absent.

IHC

  • GFAP +/-ve (focal).
  • MAP2 +ve.
  • Synaptophysin +ve.
  • NeuN +ve.
  • MIB-1: usu 1-3%.

Molecular

  • Distinct methylation profile.
  • Recurent losses on 2p and Chr. 14.[23]

  • Liponeurocytoma, HE (WC/Marvin101).

  • Liponeurocytoma, Synapto (WC/Marvin101).

  • Liponeurocytoma, HE (WC/jensflorian).

  • Liponeurocytoma, Synapto (WC/jensflorian).

DDx

Gangliocytoma

  • Grade I WHO neuronal tumour.
    • ICD-O code: 9492/0
  • Groups of irregular large neurons.
  • Non-neoplastic, reticulin-rich glial stroma.

Ganglioglioma

Not to be confused with ganglioneuroma.

General

  • Gangliolioma: Grade I WHO mixed neuronal-glial tumour (ICD-O code: 9505/1).
  • Anaplastic ganglioglioma: Grade III (ICD-O: 9505/3)
  • Rare (approx. 0.5% of all CNS tumors).
  • Usu. temporal lobe.
  • Predominantly children (mean age: 9 years).
  • Recognized as a cause of epilepsy.[24]
  • Favourable prognosis (survival rates up to 97%)
    • Insufficient data für anaplastic ganglioglioma.

Macroscopic

  • Circumscribed lesion.
  • Usu. contrast enhancing.
  • Solid, but intracortical cysts may be present.
  • Little mass effect.


Microscopic

Features:

  • Dysplastic neurons.
    • Out of regular architecture / abnormal location.
    • Cytomegaly
    • Clustering
    • Binucleated (very occassionally).
  • Atypical glia.
  • Eosinophilic granular bodies.
  • Calcification.
  • Prominent capillary network.
  • Lymphocytic cuffing.
  • May contain some reticulin.
  • Glial component may resemble:
    • Fibrillary astrocytoma.
    • Oligodendroglioma.
    • Pilocytic astrocytoma.

Anaplastic ganglioglioma:

  • Brisk mitotic activity
  • Necrosis

IHC

  • Neurons:
    • MAP2 +ve
    • Synaptophysin +ve
    • Neurofilament +ve
  • Glia:
    • CD34+/-ve
  • BRAF V600E +ve (approx. 25%, mainly ganglion cells).

Molecular

  • BRAF V600E-mutated(approx. 25%).
  • IDH1/2 wt.
  • No 1p/19q codeletion.
  • Usu. Chr. 7 gain.
  • CDKN2A deletions in anaplastic ganglioglioma.

DDx:

  • DNT.
  • Oligodendroglioma.
  • Trapped cortical neurons in diffuse astrocytoma.
  • Papillary glioneuronal tumor.
  • Dysembryoplastic neuroepithelial tumor.

Images

  • Lymphocytic cuffing in ganglioglioma (WC/jensflorian)

  • Calcification in ganglioglioma (WC/jensflorian)

  • CD34 immunostain in ganglioglioma (WC/jensflorian)

  • Pleomorphic ganglion cells in ganglioglioma (WC/jensflorian)

Lhermitte-Duclos disease

  • Abbreviated LDD.
  • AKA dysplastic cerebellar gangliocytoma.[25]
  • AKA dysplastic gangliocytoma of the cerebellum.
Main article: Lhermitte-Duclos disease

  • Dysplastic gangliocytoma (low mag).

Papillary glioneuronal tumour

  • Abbreviated PGNT.
  • A benign, supratentorial tumor of childhood.
    • Biologic course corresponds to WHO grade I.
    • Before WHO 2000, considered a Ganglioglioma variant.
  • Prominent pseudopapillary architecture.
  • Neurocytes to medium-sized ganglion cells.
  • GFAP+ core, GFAP- layer
  • Rosenthal fibers, Eosinophilic Granular bodies and lymphocytic cuffing may be present.

  • PGNT (HE) (WC/jensflorian)

Rosette-forming glioneuronal tumour of the fourth ventricle

  • Abbreviated RGNT.
  • Provisional ICD-O code: 9509/1
  • A rare benign infratentorial tumour of the midline of children and adults.
  • Biologic course corresponds to WHO grade I.
  • Glial component corresponds to pilocytic astrocytoma.
  • Neurocytic rosettes.
  • Eosinopil fibrillary cores / pseudorosettes.
  • GFAP+ in fibrillary areas, Syn+ in rosettes.
  • Neurocytic cells: MAP2+
  • MIB-1 usu. below 3%.

  • RGNT, HE stain (WC/jensflorian).

  • RGNT, higher magnification (WC/jensflorian).

Polymorphous low-grade tumor of the young (PLNTY)

Pineal tumours

Main article: Pineal gland

Embryonal tumours

DDx:

Peripheral nerve sheath tumours

Main article: Peripheral nerve sheath tumours

A classification:[26] Benign:

Malignant:

Ganglioneuroma

Not to be confused with ganglioglioma.
Main article: Ganglioneuroma


Meningioma

Main article: Meningioma

Chordoma

Main article: Chordoma

Hemangioblastoma

Main article: Hemangioblastoma

CNS lymphoma

Classification:

  • Primary CNS lymphoma.
  • Non-primary CNS lymphoma - see lymphoma article.

General - primary CNS

  • Classically periventicular distribution.
  • Usually large B cell; can be considered a type of diffuse large B cell lymphoma (DLBCL).
    • Prognosis of CNS (DLBCL) lymphomas worse than nodal (non-CNS) DLBCL.[28]

Microscopic

Features:

  • Large cell lymphoma.
    • Size = 2x diameter normal lymphocyte.
    • Nucleolus - common.
  • Perivascular clustering.

Images

www:

  • CNS lymphoma - low mag. (WC)

  • CNS lymphoma - intermed. mag. (WC)

  • CNS lymphoma - high mag. (WC)

  • CNS lymphoma - very high mag. (WC)

  • CNS lymphoma. (WC/KGH)

  • CNS lymphoma. (WC/KGH)

IHC

Can be subclassified in GCB (germinal centre B-cell-like) and non-GCB by CD10, Bcl-6, MUM1/IRF-4, and Bcl-2.[28]

Common pattern:

  • CD20 +ve - key stain.
  • CD3 -ve.
  • Ki-67 ~40%.
  • Bcl-6 +ve.
  • Bcl-1 -ve.


Ganglioneuroblastoma

Main article: Neuroblastoma

General

  • Uncommon.
  • Part of the neuroblastic tumours group which includes:[29]

Microscopic

Features:

  • Ganglion-like cells with a prominent nucleolus.
  • Small undifferentiated cells with scant cytoplasm.

  • Adrenal Ganglioneuroblastoma - Low power (SKB)

  • Adrenal Ganglioneuroblastoma - Medium power (SKB)

  • Adrenal Ganglioneuroblastoma - High power (SKB)

  • Adrenal Ganglioneuroblastoma - High power (SKB)

  • Adrenal Ganglioneuroblastoma - High power (SKB)

Images:

IHC

  • NSE +ve -- small cells.

Lesions of the sella turcica

Main article: Pituitary gland

Lesions of the sella turcica, the pituitary gland environs, is a topic for it self. The differential diagnosis for lesions in this area includes:

See also

References

  1. ↑ http://neurosurgery.mgh.harvard.edu/abta/primer.htm
  2. ↑ URL: http://www.msdlatinamerica.com/ebooks/DiagnosticNeuropathologySmears/files/4ce563fb7e8e48fc9ed8b42e296a7747.gif and http://www.msdlatinamerica.com/ebooks/DiagnosticNeuropathologySmears/sid117213.html. Accessed on: 2 November 2010.
  3. ↑ URL: http://path.upmc.edu/cases/case320/dx.html. Accessed on: 14 January 2012.
  4. ↑ URL: http://www.pathologyoutlines.com/Cnstumor.html#cystsgeneral. Accessed on: 14 January 2012.
  5. ↑ URL: http://path.upmc.edu/cases/case79/dx.html. Accessed on: 2 January 2012.
  6. ↑ Louis, DN.; von Deimling, A. (Aug 2017). "Grading of diffuse astrocytic gliomas: Broders, Kernohan, Zülch, the WHO… and Shakespeare.". Acta Neuropathol. doi:10.1007/s00401-017-1765-z. PMID 28801693.
  7. ↑ Yan H, Parsons DW, Jin G, et al. (February 2009). "IDH1 and IDH2 mutations in gliomas". N. Engl. J. Med. 360 (8): 765–73. doi:10.1056/NEJMoa0808710. PMC 2820383. PMID 19228619. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2820383/.
  8. ↑ Houillier C, Wang X, Kaloshi G, et al. (October 2010). "IDH1 or IDH2 mutations predict longer survival and response to temozolomide in low-grade gliomas". Neurology 75 (17): 1560–6. doi:10.1212/WNL.0b013e3181f96282. PMID 20975057.
  9. ↑ Rong Y, Durden DL, Van Meir EG, Brat DJ (June 2006). "'Pseudopalisading' necrosis in glioblastoma: a familiar morphologic feature that links vascular pathology, hypoxia, and angiogenesis". J. Neuropathol. Exp. Neurol. 65 (6): 529–39. PMID 16783163.
  10. ↑ http://dictionary.reference.com/browse/palisading
  11. ↑ The International Agency for Research on Cancer (Editors: Louis, D.N.; Ohgaki, H.; Wiestler, O.D.; Cavenee, W.K.) (2007). Pathology and Genetics of Tumours of Tumors of the Central Nervous System (IARC WHO Classification of Tumours) (4th ed.). Lyon: World Health Organization. pp. 88. doi:10.1007/s00401-007-0243-4. ISBN 978-9283224303.
  12. ↑ Narayan, S.; Kapoor, A.; Singhal, MK.; Jakhar, SL.; Bagri, PK.; Rajput, PS.; Kumar, HS.. "Astroblastoma of cerebrum: A rare case report and review of literature.". J Cancer Res Ther 11 (3): 667. doi:10.4103/0973-1482.140800. PMID 26458709.
  13. ↑ Sturm, D.; Orr, BA.; Toprak, UH.; Hovestadt, V.; Jones, DT.; Capper, D.; Sill, M.; Buchhalter, I. et al. (Feb 2016). "New Brain Tumor Entities Emerge from Molecular Classification of CNS-PNETs.". Cell 164 (5): 1060-72. doi:10.1016/j.cell.2016.01.015. PMID 26919435.
  14. ↑ Goode, B.; Mondal, G.; Hyun, M.; Ruiz, DG.; Lin, YH.; Van Ziffle, J.; Joseph, NM.; Onodera, C. et al. (02 2018). "A recurrent kinase domain mutation in PRKCA defines chordoid glioma of the third ventricle.". Nat Commun 9 (1): 810. doi:10.1038/s41467-018-02826-8. PMID 29476136.
  15. ↑ Hasselblatt, M.; Oyen, F.; Gesk, S.; Kordes, U.; Wrede, B.; Bergmann, M.; Schmid, H.; Frühwald, MC. et al. (Dec 2009). "Cribriform neuroepithelial tumor (CRINET): a nonrhabdoid ventricular tumor with INI1 loss and relatively favorable prognosis.". J Neuropathol Exp Neurol 68 (12): 1249-55. doi:10.1097/NEN.0b013e3181c06a51. PMID 19915490.
  16. ↑ Arnold, MA.; Stallings-Archer, K.; Marlin, E.; Grondin, R.; Olshefski, R.; Biegel, JA.; Pierson, CR.. "Cribriform neuroepithelial tumor arising in the lateral ventricle.". Pediatr Dev Pathol 16 (4): 301-7. doi:10.2350/12-12-1287-CR.1. PMID 23495723.
  17. ↑ Park, JY.; Kim, E.; Kim, DW.; Chang, HW.; Kim, SP. (Oct 2012). "Cribriform neuroepithelial tumor in the third ventricle: a case report and literature review.". Neuropathology 32 (5): 570-6. doi:10.1111/j.1440-1789.2011.01293.x. PMID 22239490.
  18. ↑ Gessi, M.; Japp, AS.; Dreschmann, V.; Zur Mühlen, A.; Goschzik, T.; Dörner, E.; Pietsch, T. (Oct 2015). "High-Resolution Genomic Analysis of Cribriform Neuroepithelial Tumors of the Central Nervous System.". J Neuropathol Exp Neurol 74 (10): 970-4. doi:10.1097/NEN.0000000000000239. PMID 26352987.
  19. ↑ Wang, AC.; Jones, DTW.; Abecassis, IJ.; Cole, BL.; Leary, SES.; Lockwood, CM.; Chavez, L.; Capper, D. et al. (Jul 2018). "Desmoplastic Infantile Ganglioglioma/Astrocytoma (DIG/DIA) are Distinct Entities with Frequent BRAFV600 Mutations.". Mol Cancer Res. doi:10.1158/1541-7786.MCR-17-0507. PMID 30006355.
  20. ↑ Gupta, K.; Salunke, P.; Kalra, I.; Vasishta, RK.. "Central liponeurocytoma: case report and review of literature.". Clin Neuropathol 30 (2): 80-5. PMID 21329617.
  21. ↑ Nishimoto, T.; Kaya, B. (Aug 2012). "Cerebellar liponeurocytoma.". Arch Pathol Lab Med 136 (8): 965-9. doi:10.5858/arpa.2011-0337-RS. PMID 22849747.
  22. ↑ Brat, DJ.; Parisi, JE.; Kleinschmidt-DeMasters, BK.; Yachnis, AT.; Montine, TJ.; Boyer, PJ.; Powell, SZ.; Prayson, RA. et al. (Jun 2008). "Surgical neuropathology update: a review of changes introduced by the WHO classification of tumours of the central nervous system, 4th edition.". Arch Pathol Lab Med 132 (6): 993-1007. doi:10.1043/1543-2165(2008)132[993:SNUARO]2.0.CO;2. PMID 18517285.
  23. ↑ Capper, D.; Stichel, D.; Sahm, F.; Jones, DTW.; Schrimpf, D.; Sill, M.; Schmid, S.; Hovestadt, V. et al. (Jul 2018). "Practical implementation of DNA methylation and copy-number-based CNS tumor diagnostics: the Heidelberg experience.". Acta Neuropathol. doi:10.1007/s00401-018-1879-y. PMID 29967940.
  24. ↑ Im, SH.; Chung, CK.; Cho, BK.; Lee, SK. (Mar 2002). "Supratentorial ganglioglioma and epilepsy: postoperative seizure outcome.". J Neurooncol 57 (1): 59-66. PMID 12125968.
  25. ↑ Yağci-Küpeli, B.; Oguz, KK.; Bilen, MA.; Yalçin, B.; Akalan, N.; Büyükpamukçu, M. (Mar 2010). "An unusual cause of posterior fossa mass: Lhermitte-Duclos disease.". J Neurol Sci 290 (1-2): 138-41. doi:10.1016/j.jns.2009.12.010. PMID 20060133.
  26. ↑ Wippold FJ, Lubner M, Perrin RJ, Lämmle M, Perry A (October 2007). "Neuropathology for the neuroradiologist: Antoni A and Antoni B tissue patterns". AJNR Am J Neuroradiol 28 (9): 1633–8. doi:10.3174/ajnr.A0682. PMID 17893219. http://www.ajnr.org/cgi/reprint/28/9/1633.
  27. ↑ URL: http://medical-dictionary.thefreedictionary.com/ganglioma. Accessed on: 8 November 2010.
  28. ↑ 28.0 28.1 Raoux D, Duband S, Forest F, et al. (June 2010). "Primary central nervous system lymphoma: Immunohistochemical profile and prognostic significance". Neuropathology 30 (3): 232–40. doi:10.1111/j.1440-1789.2009.01074.x. PMID 19925562.
  29. ↑ Shimada H, Ambros IM, Dehner LP, Hata J, Joshi VV, Roald B (July 1999). "Terminology and morphologic criteria of neuroblastic tumors: recommendations by the International Neuroblastoma Pathology Committee". Cancer 86 (2): 349–63. PMID 10421272.

External links

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