Molecular genetic analysis of a primitive neuroectodermal tumor arising after intracranial radiation and chemotherapy for leukemia.

Primitive neuroectodermal tumors are aggressive tumors of the central nervous system (CNS), yet their etiology remains unclear. We report a case of a primitive neuroectodermal tumor (PNET) arising in the cerebellum and pons 7 yr after intracranial radiation and chemotherapy for leukemia involving the CNS. This case suggests a possible link between radiation, chemotherapy, and the formation of these tumors, with a potential new pathogenetic role for somatic inactivation of the protooncogene RET.