Choroid plexus carcinoma of the fourth ventricle. Report of a case in an infant.

An 8-month-old female infant with choroid plexus carcinoma presenting in the fourth ventricle is described. The patient was initially treated with combination chemotherapy due to her young age, but developed local tumor recurrence 13 months after beginning treatment. Staging studies to detect tumor seeding of the cerebrospinal fluid were negative, and the patient received posterior fossa radiotherapy. Although the primary tumor regressed with radiation treatment, widespread disease throughout the spinal subarachnoid space subsequently developed. Choroid plexus carcinoma has a significant tendency to metastasize through the cerebrospinal fluid, and treatment of the entire neuraxis should be strongly considered for patients with this disease.