Unusual cause of relapsing hydrocephalus. Congenital intracranial teratoma.

We add clinical and pathological details of one male and one female infant with congenital pineal teratomas who died before reaching 3 months of age to the small number in the world literature. Each had a nonresectable, enormous neoplasm at the time of diagnosis, and shunting procedures were of no significant value. The pathological features of the tumors conformed in all respects to those classically described as true teratomas. An epidermal cyst, possibly metastatic, was found in the spinal subarachnoid space in one patient. There is currently no effective therapy for these neoplasms, although both were diagnosed during life. Whenever recurrent shunt insufficiency occurs in a hydrocephalic neonate, the possibility of a congenital brain tumor should be considered.