Dysgerminoma with giant cells. A case report with immunoperoxidase

A 15-year-old female with a positive pregnancy test was found to have a large ovarian tumor. Histology revealed a pure dysgerminoma with unusual giant cells, reminiscent of syncytiotrophoblast. PAP immunoperoxidase to the beta subunit of human chorionic gonadotropin (HCG) was performed on tumor sections. HCG was demonstrated within and confined to the giant cells. All studies for alpha-fetoprotein were negative. The use of immunoperoxidase in the evaluation of tumor markers and in the management of this unique tumor is discussed.