Central neurocytoma arising within a mature cystic teratoma of the ovary.

Tumors of central nervous system elements are uncommon in cystic teratomas and tend to be derived from glial or primitive neuroectodermal cells. We describe the case of a 23-year-old woman with a central neurocytoma arising in an otherwise mature cystic teratoma of the ovary. Histologically, the neurocytoma was composed of collections of oligodendroglioma like cells in a fibrillary matrix. Cytologically the tumor was identical in appearance to central neurocytomas occurring within the adult brain. It expressed synaptophysin and neuron-specific enolase, confirming its neuronal lineage, but not glial fibrillary acidic protein. The site of the tumor recapitulated the typical location of neurocytomas adjacent to the lateral ventricle in that in abutted onto an ependyma-lined cyst within the teratoma. The patient remains well and free of tumor 1 year after cystectomy, in keeping with favorable follow-up data for surgically excised central neurocytomas within the brain.