Rectal endometrial stromal sarcoma arising in endometriosis - Report of a case

PURPOSE: Endometriosis of the rectovaginal septum can barber different type s of secondary tumors that may involve the rectal wall and protrude into it s lumen, thus making diagnosis difficult. Extrauterine low-grade endometria l stromal sarcoma may rarely arise in endometriosis. The purpose of this ar ticle was to present the third case of this association. METHOD: This was a clinicopathologic study. RESULTS: h 42year-old female presented with abdom inal pain and fever. Laparotomy revealed a large pelvic mass involving the rectovaginal septum and the colonic wall and which protruded into the lumen forming endoluminal polypoid masses. Concomitant peritoneal nodules and a metastatic paracolic lymph node were also found. Histopathologically, prima ry endometriotic foci were found in close relationship with an endometrial stromal sarcoma which invaded the rectal wall. The female genital tract had no endometriotic lesions. The patient was treated by surgery and subsequen t chemotherapy and was alive and well 20 months later. CONCLUSIONS: Endomet riosis and its possible malignant changes should be taken into account in t he differential endoscopic diagnosis of rectal masses in females.