Medulloblastoma
Medulloblastoma is a malignant small round cell tumour that is found in the cerebellum.
Morphologically identical supratentorial tumours are called primitive neuroectodermal tumour (PNET).
General
- Mostly paediatric population.
- May be seen as a component of nevoid basal cell carcinoma syndrome (NBCCS).
- Gene: patched (abbreviated PTCH1).[1]
- Commonly spread via cerebrospinal fluid (CSF).[2]
- May be detected in CSF cytopathology specimens.
Gross
- Location: cerebellum - key feature.
- Morphologically identical supratentorial tumours are called primitive neuroectodermal tumour (PNET).
- Supratentorial and spinal metastases from initial tumor possible.
Microscopic
Features:[3]
- Small round cell tumour.
- Homer-Wright rosettes:
- Rosette with a meshwork of fibers (neuropil) at the centre.[4]
DDx:
Images
Medulloblastoma. (WC/KGH)
Medulloblastoma. (WC/KGH)
Homer-Wright rosettes in a medulloblastoma. (WC/jensflorian)
Cerebellar infiltrative growth. (WC/jensflorian)
Demsomplastic nodular medullloblastoma. (WC/jensflorian)
Anaplastic large cell medulloblastoma. (WC/jensflorian)
Medulloblastoma cells smear. (AFIP)
Medulloblastoma in the cerebellum. (AFIP)
Reticulin stain highlighting "pale islands" in a desmoplastic medulloblastoma (WC/jensflorian)
MIB-1 immunostaining in desmoplastic medulloblastoma (WC/jensflorian)
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Case:
Classic Medulloblastoma of the SHH type. (WC/jensflorian)
Epitheloid ribboning and nuclear moulding of tumor cells. (WC/jensflorian)
Areas of geographic necrosis. (WC/jensflorian)
Partial MAP2 immunoreactivity. (WC/jensflorian)
www:
- Medulloblastoma (ouhsc.edu).
- Medulloblastoma - several images (upmc.edu).
- Medulloblastoma with rhabdomyoblastic differentiation - several images (upmc.edu).
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:
Anaplastic variant
Features:
- Larger cells.
- Severe anaplasia.
- Polygonal cells.
See also
References
- ↑ Online 'Mendelian Inheritance in Man' (OMIM) 601309
- ↑ Lefkowitch, Jay H. (2006). Anatomic Pathology Board Review (1st ed.). Saunders. pp. 424 Q34. ISBN 978-1416025887.
- ↑ URL: http://moon.ouhsc.edu/kfung/jty1/neurotest/Q93-Ans.htm. Accessed on: 26 October 2010.
- ↑ Wippold FJ, Perry A (March 2006). "Neuropathology for the neuroradiologist: rosettes and pseudorosettes". AJNR Am J Neuroradiol 27 (3): 488–92. PMID 16551982.
- ↑ Gulino A, Arcella A, Giangaspero F (November 2008). "Pathological and molecular heterogeneity of medulloblastoma". Curr Opin Oncol 20 (6): 668–75. doi:10.1097/CCO.0b013e32831369f4. PMID 18841049.
- ↑ Rutkowski S, von Hoff K, Emser A, et al. (November 2010). "Survival and Prognostic Factors of Early Childhood Medulloblastoma: An International Meta-Analysis". J Clin Oncol 28 (33): 4961–4968. doi:10.1200/JCO.2010.30.2299. PMID 20940197.