Endometriosis of the Colon with Mixed “Germ Cell” Tumor

A 42-year-old woman was found to have endometriosis of the oviducts. Five years later she had a hysterectomy and oophorectomy, the abnormal findings at this time being endometriosis with a chocolate cyst of one ovary. At a third operation, seven years after the first, she was found to have endometriosis of the colon, associated with malignant tumor in the serosa of the intestine and in the pelvis. Histologically, there was direct transition from benign epithelium in the ectopic endometrial glands, to dysplastic and neoplastic tissue. In different areas, the tumor included elements of yolk sac type (endodermal sinus tumor), choriocarcinoma, and teratoma. The implications of this unique transformation and combination are discussed briefly.