A clinico-pathological study of adult histiocytosis X involving the brain.

Abstract
Adult histiocytosis X involving the CNS caused progressive spastic paraparesis. The diagnosis was made by immunoreactive anti-S100 protein antibody staining and from the presence of Birbeck granules in biopsy specimens of skin lesions. Neuropathological examination showed massive proliferation and infiltration of S-100 containing histiocyte-like cells and reactive astrocytes throughout the CNS.