GFAP and Kaposi's sarcoma: Immunohistochemistry is very important in the differential diagnosis of intracranial angiosarcoma.Some immunohistochemical markers such as ERG, vementin, S100, HMB-45, MIB-1, UEA-1, and GFAP, are particularly useful in making differential diagnosis with hemangioblastoma, Kaposi’s sarcoma, hemangioendothelioma, cavernous angioma, carcinoma metastases, and epithelious melanoma [3, 9].