Primary leptomeningeal primitive neuroectodermal tumor.

Leptomeningeal metastases are a common complication of medulloblastomas and other primitive neuroectodermal tumors (PNETs). Much rarer are PNETs apparently arising in the leptomeninges. An 8-year-old boy presented with headache and vomiting, due to neoplastic meningitis from primary neuroectodermal tumor without an identifying mass. After craniospinal irradiation and chemotherapy (carboplatin, vincristine, cyclophosphamide and lomustine) the boy was in remission for 14 months, then suffered several relapses despite various chemotherapy regimens. After the initial presentation of 3.5 years the boy began to suffer from prolonged refractory non-convulsive status epilepticus and later expired from progression of primary leptomeningeal PNET.