Central Nervous System Primitive Neuroectodermal Tumors: A Clinicopathologic and Genetic Study of 33 Cases
Article first published online: 25 JUN 2009
© 2009 The Authors. Journal Compilation © 2009 International Society of Neuropathology
Volume 20, Issue 2, pages 441–450, March 2010
How to Cite
Behdad, A. and Perry, A. (2010), Central Nervous System Primitive Neuroectodermal Tumors: A Clinicopathologic and Genetic Study of 33 Cases. Brain Pathology, 20: 441–450. doi: 10.1111/j.1750-3639.2009.00314.x
- Issue published online: 2 FEB 2010
- Article first published online: 25 JUN 2009
- Received 22 May 2009; accepted 17 June 2009.
- fluorescence in situ hybridization;
- primitive neuroectodermal tumor;
Central nervous system (CNS) primitive neuroectodermal tumors (PNETs) include supratentorial, brain stem, and spinal cord tumors with medulloblastoma-like histopathology. The prognostic impact of various pathologic and genetic features has not been thoroughly investigated. After re-diagnosis of three infantile cases as atypical teratoid/rhabdoid tumor (AT/RT), 33 remaining CNS PNETs were retrieved for clinicopathologic and fluorescence in situ hybridization studies. Anaplastic and/or large cell features were seen in 18 of 33 (55%) examples and survival was decreased in these patients (P = 0.036). MYCN or MYCC gene amplifications were noted in about half, with a trend towards decreased survival (P = 0.112). Polysomies of chromosomes 2 and 8 were each individually associated with decreased survival in children, with an even stronger association when combined (P = 0.013). Neither EWS gene rearrangements, nor AT/RT-like 22q deletions were encountered. We conclude that in CNS PNET: (i) routine application of INI1 immunohistochemistry helps rule out AT/RT, particularly in infants; (ii) MYC gene amplifications (especially MYCN) are common; (iii) involvement of CNS parenchyma by Ewing sarcoma/peripheral PNET is rare enough that EWS gene testing is not necessary unless significant dural involvement is present; and (iv) both anaplastic/large cell features and polysomies of 2 and 8 are associated with more aggressive clinical behavior.