Lipoma of the ambient cistern causing obstructive hydrocephalus.

A 62-year-old patient with lipoma of the ambient cistern and marked hydrocephalus is described. Intracranial lipomas are maldevelopmental lesions, which rarely produce neurological symptoms. The anatomopathological and clinical features of the lipomas of the ambient cistern are reviewed on the basis of the other reported cases. The importance of the computerized tomography and nuclear magnetic resonance for the diagnosis and the indications for the surgery are also discussed.