Extracranial skeletal metastasis from a pinealoblastoma. A case report and review of the literature.

Osseous metastases from primary central nervous system (CNS) tumors are rare. The CNS tumors that most frequently metastasize to bone are the glioblastoma multiforme and the medulloblastoma. In this report, a 22-year-old woman sought treatment for a lytic lesion in her right proximal femur 18 months after a craniotomy to remove a pinealoblastoma, a rare primitive neuroectodermal tumor of the pineal gland. An extensive evaluation demonstrated no other primary tumors. A biopsy of the femoral lesion revealed that it was morphologically identical to the pinealoblastoma, and special immunohistochemical stains were performed that verified neuronal differentiation. This may be the first report of a pinealoblastoma associated with an extracranial skeletal metastasis.