Distribution of glial fibrillary acidic protein in central nervous system lesions of tuberous sclerosis.

The distribution of glial fibrillary acidic protein (GFAP) in the central nervous system (CNS) lesions of tuberous sclerosis (TS) was examined using antiserum against GFAP and the peroxidase antiperoxidase method of Sternberger. In cortical tubers there were islands of gemistocytic astrocytes staining intensely for GFAP and occasional giant cells having some cytoplasmic staining. The majority of the cortical giant cells had no GFAP. The islands were separated by areas devoid of astrocytes with perikaryal staining. A faintly staining fibrous network was found between these islands. The majority of cells in the subependymal nodules stained. The retinal phakoma stained but not as intensely as the subependymal nodules. There was no staining whatsoever in the giant cell subependymal tumors. Absence of GFAP staining in the subependymal giant cell tumors makes their classification as astrocytomas less certain.