dysgerminoma /dis′jərminō″mə/ pl. dysgerminomas, dysgerminomata [Gk, dys + L, germen, germ; Gk, oma, tumor] , a rare malignant tumor of the ovary that occurs in young women and is believed to arise from the undifferentiated germ cells of the embryonic gonad. The tumor is histologically identical to seminoma. Dysgerminomas are extremely sensitive to irradiation and chemotherapy, and most patients retain their fertility. Also called embryoma of the ovary, ovarian seminoma.
