Primary congenital rhabdoid tumor of the brain with neoplastic hydranencephaly.

A child with shunted hydranencephaly and presumed ventriculitis was found to have a primary congenital rhabdoid tumor (RT) of the brain. The child died and a complete autopsy was carried out. The cerebral hemispheres were replaced by a single thin-walled cavity studed with tumor nodules and filled with thick, viscous fluid. The posterior fossa and visceral organs were free of tumor. This case is unique because the rhabdoid tumor was primary to the brain, it was congenital, and it massively replaced the cerebral hemispheres, causing hydranencephaly. Only three other cases of primary RT of the brain with complete autopsy examination have been reported. Cases of congenital rhabdoid tumors are not known in the literature. Hydranencephaly with a highly proteinaceous fluid should alert the physician to the possibility of a neoplasm. When the fluid in presumed ventriculitis is sterile, cerebral biopsy should be considered.