Neuropathology tumours
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
Adult
Four most common types of brain tumours:[1]
- Metastatic brain tumours (barely edges out primary tumours)
- Lung (most common).
- Breast.
- Melanoma.
- Renal cell carcinoma (RCC).
- Glioblastoma (previously known as glioblastoma multiforme).
- Anaplastic astrocytoma.
- Meningioma.
Children
- Astrocytoma.
- Medulloblastoma.
- Ependymoma.
Location (most common)
Certain tumours like to hang-out at certain places:[2]
- Cerebrum:
- Cortical based - oligodendroglioma.
- Grey-white junction - metastases.
- White matter - astrocytoma, glioblastoma.
- Periventricular - CNS lymphoma.
- Cystic - ganglioglioma, pilocytic astrocytoma, pleomorphic xanthoastrocytoma.
- Cerebellum:
- Midline/central - medulloblastoma.
- Cystic lesion - pilocytic astrocytoma (younger individual), hemangioblastoma (older individual).
- Solid lesion (older individual) - metastasis.
- Spinal cord:
- Ependymoma, glioblastoma.
- Filum terminale - myxopapillary ependymoma, paraganglioma.
Filum terminale
- Filum terminale = bottom end of the spinal cord - has a limited differential.
DDx:[3]
Cerebellopontine angle
- Abbreviated CP angle.
DDx:[4]
- Schwannoma.
- Meningioma.
- Dermoid cyst/epidermoid cyst.
- Ependymoma.
- Choroid plexus papilloma.
Cystic tumours
DDx:[5]
- Pilocytic astrocytoma.
- Pleomorphic xanthoastrocytoma.
- Ganglioglioma.
- Hemangioblastoma.
- Craniopharyngioma.[6]
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.
- 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.
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 | |
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 | nil | |
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 | |
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 | |
Infiltrative astrocytoma (WHO grade II or grade III) | 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+/-, GFAP+ | |
Glioblastoma (WHO grade IV) | 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+ | |
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 |
† Rosenthal fibres at the periphery of a lesion are a non-specific finding seen in chronic processes.
Brain metastasis
Infiltrative astrocytomas
Overview
- Low-grade (diffuse) astrocytomas (Grade II).
- Anaplastic astrocytomas (Grade III).
- Glioblastoma (Grade IV).
Notes:
- Non-infiltrative gliomas:
- Pilocytic astrocytoma (WHO Grade I).
- Dysembryoplastic neuroepithelial tumour (DNT), (WHO Grade I).
Microscopic
- 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:
- Endothelial proliferation in a GBM (ouhsc.edu).
- Endothelial proliferation (ouhse.edu).
- Gemistocytic astrocytoma - several images (upmc.edu).
Notes:
- Glial vs. non-glial tumours:
- Glial: "blends into brain"/gradual transition to non-tumour brain.
- Non-glial: no glial processes.
- Rosenthal fibres within the tumour... make it into a 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.[9]
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.
Images
Glioblastoma:
Anaplastic astrocytoma:
Table of common gliomas - grading
Histomorphologic comparison of common gliomas:
Entity | Rosenthal fibres / EGBs |
Nuclear atypia | Mitoses | Necrosis or MVP | Infiltrative | Image |
Pilocytic astrocytoma | yes | usu. no | usu. no | usu. no | no | |
Low-grade astrocytoma | no | yes | no | no | yes | image? |
Anaplastic astrocytoma | no | yes | yes | no | yes | |
Glioblastoma | no | yes | yes | yes | yes |
Notes:
- MVP = microvascular proliferation.
- EGBs = eosinophilic granular bodies.
IHC
- GFAP - should stain cytoplasm of tumour cells and the perikaryon (nuclear membrane).
- Ki-67 - usu. high >20% of cells.
- p53 - often +ve.
- IDH1 (isocitrate dehydrogenase 1).
- +ve in tumours that arose from low-grade gliomas.[10]
- Image: IDH1 +ve in glioblastoma (WP).
- +ve in tumours that arose from low-grade gliomas.[10]
Notes:
- IDH1 and IDH2 mutations - better survival.[11]
Pilocytic astrocytoma
Pleomorphic xanthoastrocytoma
- Abbreviated PXA.
Dysembryoplastic neuroepithelial tumour
- Abbreviated DNT.
Subependymal giant cell astrocytoma
- Abbreviated SEGA.
Pilomyxoid astrocytoma
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).
Oligodendroglioma
Oligoastrocytoma
Meningioma
Peripheral nerve sheath tumours
A classification:[12]
- Benign:
- Malignant:
Schwannoma
Neurofibroma
Ganglioneuroma
- Not to be confused with ganglioglioma.
Ependymoma
Subependymoma
Choroid plexus papilloma
Choroid plexus carcinoma
Chordoma
Hemangioblastoma
Medulloblastoma
- Tumour of cerebellum - key feature.
- Morphologically identical supratentorial tumours are called primitive neuroectodermal tumour (PNET).
Primitive neuroectodermal tumour
Embryonal tumour with abundant neuropil and true rosettes
- Abbreviated ETANTR.
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.[14]
Microscopic
Features:
- Large cell lymphoma.
- Size = 2x diameter normal lymphocyte.
- Nucleolus - common.
- Perivascular clustering.
Images
www:
IHC
Can be subclassified in GCB (germinal centre B-cell-like) and non-GCB by CD10, Bcl-6, MUM1/IRF-4, and Bcl-2.[14]
Common pattern:
- CD20 +ve - key stain.
- CD3 -ve.
- Ki-67 ~40%.
- Bcl-6 +ve.
- Bcl-1 -ve.
Neurocytoma
Central neurocytoma
- Abbreviated CNC.
Ganglioglioma
- Not to be confused with ganglioneuroma.
General
Microscopic
Features:
- Atypical neurons.
- Atypical glia.
Images:
Lhermitte-Duclos disease
- Abbreviated LDD.
- AKA dysplastic cerebellar gangliocytoma.[16]
- AKA dysplastic gangliocytoma of the cerebellum.
Ganglioneuroblastoma
General
- Uncommon.
- Part of the neuroblastic tumours group which includes:[17]
- Ganglioneuroma (benign).
- Ganglioneuroblastoma (intermediate).
- Neuroblastoma (aggressive).
Microscopic
Features:
- Ganglion-like cells with a prominent nucleolus.
- Small undifferentiated cells with scant cytoplasm.
Images:
IHC
- NSE +ve -- small cells.
Lesions of the sella turcica
Lesions of the sella turcica, the pituitary gland environs, is a topic for it self. The differential diagnosis for lesions in this area includes:
- Pituitary adenoma.
- Craniopharyngioma.
- Rathke cleft cyst.
- Germ cell tumour.
- Meningioma.
- Pilomyxoid astrocytoma - in children.
See also
References
- ↑ http://neurosurgery.mgh.harvard.edu/abta/primer.htm
- ↑ URL: http://www.msdlatinamerica.com/ebooks/DiagnosticNeuropathologySmears/files/4ce563fb7e8e48fc9ed8b42e296a7747.gif and http://www.msdlatinamerica.com/ebooks/DiagnosticNeuropathologySmears/sid117213.html. Accessed on: 2 November 2010.
- ↑ JLK. 31 May 2010.
- ↑ R. Kiehl. 8 November 2010.
- ↑ URL: http://path.upmc.edu/cases/case320/dx.html. Accessed on: 14 January 2012.
- ↑ URL: http://www.pathologyoutlines.com/Cnstumor.html#cystsgeneral. Accessed on: 14 January 2012.
- ↑ 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.
- ↑ http://dictionary.reference.com/browse/palisading
- ↑ URL: http://path.upmc.edu/cases/case79/dx.html. Accessed on: 2 January 2012.
- ↑ 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/.
- ↑ 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.
- ↑ 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.
- ↑ URL: http://medical-dictionary.thefreedictionary.com/ganglioma. Accessed on: 8 November 2010.
- ↑ 14.0 14.1 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.
- ↑ 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.
- ↑ 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.
- ↑ 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.