Difference between revisions of "Neuropathology tumours"
Jump to navigation
Jump to search
m (→Astrocytomas) |
(→Meningioma: fix classification) |
||
| Line 190: | Line 190: | ||
**Low mitotic rate. | **Low mitotic rate. | ||
*Grade 2: | *Grade 2: | ||
**Intermediate mitotic rate (>= 4 mitoses/HPF - for whatever ''HPF'' means, see [[HPFitis]].) | **Brain-invasive meningioma. | ||
**Three of the following five features: | ***Protrusion of meningioma into brain. | ||
**#Sheeting architecture. | ****Meninogioma with entraped GFAP +ve tissue. | ||
**#High NC ratio; clusters of "lymphocyte-like" cells. | **Atypical meningioma. | ||
**#Hypercellularity. | ***Intermediate mitotic rate (>= 4 mitoses/10 HPF - for whatever ''HPF'' means, see [[HPFitis]].) | ||
**#Macronucleoli. | ***Three of the following five features: | ||
**#Necrosis not caused by treatment, e.g. radiation or embolization. | ***#Sheeting architecture. | ||
***#High NC ratio; clusters of "lymphocyte-like" cells. | |||
***#Hypercellularity. | |||
***#Macronucleoli. | |||
***#Necrosis not caused by treatment, e.g. radiation or embolization. | |||
*Grade 3: | *Grade 3: | ||
**High mitotic rate (>=20 mitoses/HPF - for whatever ''HPF'' means, see [[HPFitis]].) | **High mitotic rate (>=20 mitoses/10 HPF - for whatever ''HPF'' means, see [[HPFitis]].) | ||
**"Frank anaplasia"; marked nuclear atypia. | **"Frank anaplasia"; marked nuclear atypia. | ||
Revision as of 17:49, 4 November 2010
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 also includes peripheral nerve sheath tumours.
Brain tumours
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 aka glioblastoma multiforme.
- Anaplastic (malignant) 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.
Primary vs. secondary
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/.
Astrocytomas
Overview
- Pilocytic astrocytomas (WHO Grade I).
- Dysembryoplastic neuroepithelial tumour (DNT), (WHO Grade I).
- Low-grade (diffuse) astrocytomas (Grade II).
- Anaplastic astrocytomas (Grade III).
- Glioblastoma (Grade IV).
Microscopic
- Glial processes - key feature.
- Thin stringy cytoplasmic processes - best seen at high power in less cellular areas.
- Nuclear pleomorphism.
- Mitotic figures.
- Microvascular proliferation or necrosis with pseudopalisading tumour cells.
- Pseudopalisading tumour cells = high tumour cell density adjacent to regions of necrosis; palisade = a fence of pales forming a defense barrier or fortification.
Image:
Notes:
- Glial vs. non-glial tumours:
- Glial: "blends into brain"/gradual transition to non-tumour brain.
- Non-glial: no glial processes.
Filum terminale
- Bottom end of the spinal cord - has a limited differential.
DDx:[5]
- Meningioma.
- Myxopapillary ependymoma.
- Neurofibroma.
- Schwannoma.
- Paraganglioma.
Pilocytic astrocytoma
General
- Low-grade astrocytoma.
- Classically in the cerebellum in children.
- The optic glioma associated with neurofibromatosis 1.
Gross
- Do NOT smear.
Microscopic
Features:
- Rosenthal fibres - key feature.
Images:
DDx (of Rosenthal fibers):[6]
- Chronic reactive gliosis.
- Subependymoma.
- Ganglioma.
- Alexander's disease (rare leukodystrophy).
Oligodendroglioma
General
- Arise from oligodendrocytes.
Usual location:
- Fourth ventricle.
- Intramedullary spinal cord.
Microscopic
Features:
- Highly cellular lesion composed of:
- Cells resembling fried eggs (oligodendrocytes) with:
- Round nucleus - key feature.
- Distinct cell borders.
- Moderate-to-marked nuclear atypia.
- Clear cytoplasm - useful feature (if present).
- Some oligodendrogliomas have eosinophilic cytoplasm with focal perinuclear clearing.
- Acutely branched capillary sized vessels - "chicken-wire" like appearance.
- Abundant, delicate appearing; may vaguely resemble a paraganglioma at low power.
- Cells resembling fried eggs (oligodendrocytes) with:
- Calcifications - important feature.[7]
Images:
Notes:
- Few neural tumours have round nuclei - DDx:
- Oligodendroglioma.
- Lymphoma.
- Clear cell variant of ependymoma.
- Germ cell tumour (dysgerminoma/seminoma).
IHC
Features:
- GFAP +ve.
- EMA +ve.
Molecular pathology
Losses of 1p and 19q both helps with diagnosis and is prognostic:[8]
- Greater chemosensitivity
- Better prognosis.
Peripheral nerve sheath tumours
A classification:[9]
- Benign:
- Schwannoma.
- Neurofibroma.
- Perineurioma.
- Traumatic neuroma.
- Malignant:
- Malignant peripheral nerve sheath tumour (MPNST).
Meningioma
General
- Common.
- Extra-axial. (???)
- Most are benign.
- May be malignant.
- May be seen in genetic disorders such as neurofibromatosis.[10]
Microscopic
Features (memory device WTC):
- Whorled appearance - key feature.
- Thick-walled blood vessels, usually prominent.
- Calcification.
Many subtypes exist:
- Atypical meningioma.
- Has invasion of the brain - WHO Grade 2.
- Angiomatous meningioma.
- Others.
Images:
DDx:
- Cerebral angioid angiopathy. (???)
Notes:
- May involute into benign sclerotic tissue.[11]
Histomorphologic grading
Grading:[12]:
- Grade 1:
- Low mitotic rate.
- Grade 2:
- Brain-invasive meningioma.
- Protrusion of meningioma into brain.
- Meninogioma with entraped GFAP +ve tissue.
- Protrusion of meningioma into brain.
- Atypical meningioma.
- Intermediate mitotic rate (>= 4 mitoses/10 HPF - for whatever HPF means, see HPFitis.)
- Three of the following five features:
- Sheeting architecture.
- High NC ratio; clusters of "lymphocyte-like" cells.
- Hypercellularity.
- Macronucleoli.
- Necrosis not caused by treatment, e.g. radiation or embolization.
- Brain-invasive meningioma.
- Grade 3:
- High mitotic rate (>=20 mitoses/10 HPF - for whatever HPF means, see HPFitis.)
- "Frank anaplasia"; marked nuclear atypia.
IHC
- EMA +ve.[13]
- Other CKs usu. -ve.
Schwannoma
General
- Tumour of tissue surrounding a nerve.
- Axons adjacent to the tumour are normal... but may be compressed.
Microscopic
Features:[9]
- Antoni tissue (type A and type B).
- Verocay bodies - paucinuclear area surrounded by nuclei.
Antoni A
- Cellular.
- 'Fibrillary, polar, elongated'.
Comment: May look somewhat like scattered matchsticks.
Antoni B
- Loose microcystic tissue.
- Adjacent to Antoni A.
Micrographs:
Neurofibroma
General:[9]
- Composed of Schwann cells, axons, fibrous material.
Appearance/morphology:[9]
- Plexiform growth pattern - "bag of worms".
Ependymoma
General
- Called the forgotten glial tumour.
Comes in two flavours:
- Ependymoma (not otherwise specified).
- Myxopapillary ependymoma.
- Classically at filum terminale.
Microscopy
Classic ependymoma
Features:
- Cells have a "tadpole-like" morphology.
- May also be described as ice cream cone-shaped.[14]
- Rosettes - cells arranged in a pseudoglandular fashion.
- "Nucleus free zones" - cells arranged around a blood vessel (perivascular pseudorosettes); nuclei of cells distant from the blood vessel, i.e. a rim of cytoplasm (from tumour cells) surrounds the blood vessel.
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)
- The nucleus free zone is composed of tumour cell cytoplasm that is adjacent to an unseen blood vessel.
- Nuclear feature monotonous, i.e. "boring".[15]
- There is little variation in size, shape and staining.
Images:
DDx (classic ependymoma):
- Subependymoma.
Myxopapillary ependymoma
Features:
- Perivascular pseudorosettes:
- Myxoid material surround blood vessels.
- Myxoid material surrounded by tumour cells.
- Myxoid material surround blood vessels.
Images:
- Myxopapillary ependymoma (bmj.com) - part of careers.bmj.com article on paediatric pathology.
- Myxopapillary ependymoma - cytology (WC).
Choroid plexus papilloma
Microscopy
Features:
- Papillae.
- Psammoma bodies.
Image:
Chordoma
General
- Location: usually sacrum or clivus.
Microscopic
Features:[16]
- 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.
Image(s):
IHC
Features:
- S100 +ve.
- CK +ve.
- Brachyury +ve.
Hemangioblastoma
General
- Usually cerebellar.
- Associated with von Hippel-Lindau syndrome.
Microscopic
Features:[19]
- Vascular.
- Polygonal stromal cells with:
- Hyperchromatic nuclei.
- Vacuolar cytoplasm.
Images:
Medulloblastoma
General
- Paediatric population. (???)
Microscopic
Features:[20]
- Homer-Wright rosettes.
Image:
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.
- ↑ 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
- ↑ JLK. 31 May 2010.
- ↑ MUN. 9 Mar 2009.
- ↑ URL: http://www.emedicine.com/radio/topic481.htm.
- ↑ Fontaine D, Vandenbos F, Lebrun C, Paquis V, Frenay M (2008). "[Diagnostic and prognostic values of 1p and 19q deletions in adult gliomas: critical review of the literature and implications in daily clinical practice]" (in French). Rev. Neurol. (Paris) 164 (6-7): 595–604. doi:10.1016/j.neurol.2008.04.002. PMID 18565359.
- ↑ 9.0 9.1 9.2 9.3 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://moon.ouhsc.edu/kfung/jty1/neurotest/Q13-Ans.htm. Accessed on: 26 October 2010.
- ↑ URL: http://radiographics.rsna.org/content/23/3/785.long. Accessed on: 3 November 2010.
- ↑ Perry, Arie; Brat, Daniel J. (2010). Practical Surgical Neuropathology: A Diagnostic Approach: A Volume in the Pattern Recognition series (1st ed.). Churchill Livingstone. pp. 194. ISBN 978-0443069826.
- ↑ Perry, Arie; Brat, Daniel J. (2010). Practical Surgical Neuropathology: A Diagnostic Approach: A Volume in the Pattern Recognition series (1st ed.). Churchill Livingstone. pp. 13. ISBN 978-0443069826.
- ↑ http://www.pathology.vcu.edu/WirSelfInst/tumor-2.html
- ↑ MUN. 6 Oct 2009.
- ↑ Tadrous, Paul.J. Diagnostic Criteria Handbook in Histopathology: A Surgical Pathology Vade Mecum (1st ed.). Wiley. pp. 184. ISBN 978-0470519035.
- ↑ URL:http://www.ncbi.nlm.nih.gov/omim/601397. Accessed on: 18 May 2010.
- ↑ URL: http://www.jstor.org/pss/86845. Accessed on: 18 May 2010.
- ↑ URL: http://emedicine.medscape.com/article/340994-media. Accessed on: 23 June 2010.
- ↑ URL: http://moon.ouhsc.edu/kfung/jty1/neurotest/Q93-Ans.htm. Accessed on: 26 October 2010.
