Primary germinoma of the spinal cord: a case report with 28-year follow-up and review of the literature.

Germ cell neoplasms occur in extra-gonadal midline locations of the retroperitoneum, mediastinum, pineal gland, areas of the suprasellar cistern, and rarely in the spinal cord. We recently reviewed a case of an unresectable lumbar spinal cord tumor in a 16-year-old female previously diagnosed as "metastatic poorly differentiated carcinoma." An extensive evaluation for a primary neoplasm at that time was unsuccessful and the patient was treated with local radiation therapy. Recently, additional histochemical and immunocytochemical studies were performed on the archival formalin-fixed paraffin-embedded material and the clinical history was reviewed. These ancillary studies (including positive immunohistochemical staining for placental alkaline phosphatase) support a diagnosis of intramedullary germinoma of the conus medullaris. This patient has enjoyed 28 years of disease free survival which reflects the radiosensitive nature of this neoplasm. These data lend support to the existence of a primary germinoma in the spinal cord and illustrate the utility of using histochemical stains and immunohistochemistry to assist in diagnosing this treatable neoplasm.