Primitive neuroectodermal tumor

Overview
Primitive Neuroectodermal Tumors, or PNET, refers to two different tumor types. These include Peripheral PNET and CNS PNET. This can be a source of confusion.

Ependymoblastoma
Ependymoblastoma is a synonym for PNET

Peripheral PNET
The Peripheral PNET is now thought to be virually identical to Ewing sarcoma:

"Current evidence indicates that both Ewing's sarcoma and PNET have a similar neural phenotype and, because they share an identical chromosome translocation, they should be viewed as the same tumor, differing only in their degree of neural differentiation. Tumors that demonstrate neural differentiation by light microscopy, immunohistochemistry, or electron microscopy have been traditionally labeled PNETs, and those that are undifferentiated by these analyses have been diagnosed as Ewing's sarcoma."

PNET of the CNS
PNET of the CNS are grossly divided into supratentorial PNET and infratentorial PNET, the latter being more common.

An example of infratentorial PNET includes Medulloblastomas, which occurs in the cerebellum.

An example of supratentorial PNET includes Pinealoblastomas, which occurs in the pineal region.

Model
Using gene transfer of SV40 large T-antigen in neuronal precursor cells of rats, a brain tumor model was established. The PNETs were histologically indistinguishable from the human counterparts and have been used to identify new genes involved in human brain tumor carcinogenesis. . The model was used to confirm p53 as one of the genes involved in human medulloblastomas, but since only about 10 % of the human tumors showed mutations in that gene, the model can be used to identify the other binding partners of SV40 Large T- antigen, other than p53.

Acknowledgements
The content on this page was first contributed by: C. Michael Gibson, M.S., M.D.

Initial content for this page in some instances came from Wikipedia

Primitiv neuroektodermaler Tumor Obwodowy niedojrzały guz neuroektodermalny