Prenatal diagnosis of a fetal intracranial tumor.

Neonatal intracranial tumors are rare and usually indicate a poor prognosis. The first case report of the identification of a fetal intracranial tumor by transabdominal ultrasonography was in 1980. Transvaginal ultrasonography and MR imaging have recently been employed to improve the imaging of fetal intracranial structures and abnormalities. Neonatal brain biopsy is still necessary, however, to assign a definitive diagnosis, since images of two histologically different tumors can appear the same. Teratomas are the most frequent intracranial tumors found in the neonate, with meningeal sarcoma, craniopharyngioma, lipoma of the corpus callosum, and oligodendroglioma being found less commonly. We report a patient diagnosed prenatally as having an enlarging intracranial mass that proved to be a gangliocytoma.