Abstract: 12 intraeranial Primary Germinomas were studied by immunohistochemical Avidin-Biotin-Complex method.6 of 12 cases showed positive cells of pregnancy-specific betal-glyco-protein (SP₁);3 of 12 cases were postive for human ehorionic gonadotropin (hCG) and 3 of 12 cases were postive of human placental lactogen (hPL).These cells resembled the extrav-ilous trophoblasts.According to the findings we consider the origins of intraeranial Primary Germinoma are primordial germ cells.They are able to secrete hCG,hPL and SP₁.

Key words: intracranial Primary Germinoma, immunohistochemistry, pregnancy specific betal-glyco protein, human chorionic gonadotropin, human placental lactogen