CT and MR findings in diffuse cerebral histiocytosis: case report.

Intracranial involvement with histiocytosis is usually limited to the hypothalamus and associated with extensive extracranial disease. We report the CT and MR findings in a patient with biopsy-proved histiocytosis presenting as multifocal intracranial involvement without any systemic disease. While extrahypothalamic CNS involvement by histiocytosis is well recognized (1-9], infiltrative brain involvement in the absence of systemic disease is unusual.