Massive congenital intracranial teratoma diagnosed in utero.

The authors describe a case of congenital intracranial teratoma. The patient was diagnosed to be hydrocephalic at 29 weeks' gestation, and to have a huge intraventricular mass lesion at 34 weeks' gestation. Subsequently, the patient underwent subtotal resection of the mass, resulting in a significant decrease in the remarkably elevated alpha-fetoprotein in serum and cerebrospinal fluid. Histological analysis revealed a malignant teratoma, also with alpha-fetoprotein-positive elements in the immunohistochemical study.