Immunocytochemical identification of human chorionic gonadotropin- and alpha-fetoprotein-producing cells of hepatoblastoma associated with precocious puberty.

A one-year-five-month-old boy with hepatoblastoma producing both human chorionic gonadotropin (hCG) and alpha-fetoprotein (AFP) is presented. Histologically, the primary tumor was mainly composed of well differentiated hepatoblastoma cells, with minor areas of poorly differentiated cells. Immunoperoxidase staining of the tumor for hCG and AFP showed that a few well differentiated, fetal type cells and multinucleated giant cells were positive for hCG, and AFP was never stained in the same cells. In areas where cells were poorly differentiated, positive reactions for either hCG or AFP were not observed. Electron microscopic studies revealed focal aggregates of cytoplasmic cored vesicles in some tumor cells, similar to secretory granules.