Intraventricular and leptomeningeal dissemination of a pilocytic cerebellar astrocytoma in a child with a ventriculoperitoneal shunt: case report.

Dissemination of a pilocytic cerebellar astrocytoma is a very rare occurrence. So far only eight cases have been reported in the literature and in only one of these cases had the tumour spread into the ventricles. We report a case of a child who presented with communicating hydrocephalus and a small cerebellar lesion. The patient was initially treated by a ventriculoperitoneal (VP) shunt and the lesion was followed-up. Two years later, intraventricular and leptomeningeal dissemination of the tumour which proved to be a pilocytic astrocytoma was documented. The role of the VP shunt in diverting metastasizing tumour cells into the ventricles is discussed.