Selective localization of gamma-enolase in stromal cells of cerebellar hemangioblastomas

Three cases of cerebellar hemangioblastoma were studied using the immunoperoxidase technique to localize gamma-enolase, also known as neuron-specific enolase. The stromal cells demonstrated positive staining for gamma-enolase, while endothelial cells and pericytes showed no reactivity. Two vascular lesions, an angiosarcoma and a cutaneous angioma, were studied and found to be nonreactive for gamma-enolase. All tumors were also tested for factor VIII/von Willebrand factor, glial fibrillary acidic protein, and the S-100 protein. The lack of expression of gamma-enolase in endothelial cells of hemangioblastomas demonstrates a clear antigenic distinction from neighboring gamma-enolase-positive stromal cells. The significance of this finding and its implications for stromal cell histogenesis are discussed.