Abstract
A 15-year-old female was hospitalized because of amenorrhea, loss of appetite, polyuria, and polydipsia that had persisted for 2 years. Endocrinological examination revealed a high serum level of human chorionic gonadotropin (HCG) (74 mIU/ml) and hyperprolactinemia. Computed tomograms showed an intrasellar mass lesion with limited suprasellar extension. A histological diagnosis of germinoma was made after surgery via the transsphenoidal route. The tumor responded well to radiation therapy and the serum HCG became negative within a short time. Immunohistochemical study involving the peroxidase-antiperoxidase technique demonstrated immunoreactive HCG not only in syncytiotrophoblastic giant cells but also in mononuclear cells, which could not be differentiated from epithelioid tumor cells. The neuroradiological and immunohistochemical peculiarities of this case are discussed.
