Rectal endometriosis mimicking a large polypoid rectal cancer

Cho YJ et al. Rectal endometriosis mimicking a large polypoid rectal cancer /C180Endoscopy 2006; 38: E48/C177E49 Endometriosis is a disorder in which en− dometrial glandular tissue and stroma are found outside the uterus; it involves the colorectum in about 5 % of cases [1, 2]. It can occasionally be difficult to differ− entiate between colonic endometriosis, usually manifest as strictures or external compression, and colon cancer or colitis [3]. In particular, the rare polypoid endo− metriosis is hardly distinguishable from colonic neoplasm [4]. More careful in− spection and diagnostic methods are therefore required. We report a case of rectal polypoid endometriosis mimicking a large polypoid rectal carcinoma. A 29−year−old woman presented with al− teration in bowel habit and intermittently blood−tinged stools over a period of a few months. Colonoscopy revealed a large ul− cerating polypoid mass 8 cm from the anal verge which nearly obstructed the lumen (Figure 1). We thought that this was a polypoid rectal adenocarcinoma. Computed tomography revealed an en− hancing soft−tissue mass with pericolic tumor infiltration, and bilateral cystic ov arian masses. Endoscopic biopsy, which was performed on two separate occa− sions, showed chronic active inflamma− tion with granulation tissue and regen− eration−type cytological atypia at first, and a hamartoma at the second biopsy. Because rectal cancer could not be ruled out, the patient underwent low anterior resection and cystectomy. The mass w as attached to the rectal wall and was com− posed of multiple hemorrhagic, grayish polyps (Figure 2). Microscopic examina− tion showed endometrial glands and sur− rounding stroma, and a diagnosis of rectal endometriosis was made (Figure 3). Pathological examination of the ovarian cysts showed an endometrioma on the right ov ary and a corpus luteum cyst on the left. A pericolic lymph node showed reactive hyperplasia. Although endometriosis is asymptomatic in many patients, rectosigmoid endome− triosis can result in changes in bowel hab− it. Magnetic resonance imaging has been proved to be valuable in the diagnosis of endometriosis [1]. If the colonic mucosa is not involved, the exact diagnosis might not be made by colonoscopic biopsy [5]. Laparotomy is a therapeutic option [2]. Endoscopy_UCTN_Code_CCL_1AD_2AC Rectal endometriosis mimicking a large polypoid rectal cancer DOI: 10.1055/s−2006−944678 Figure 3 Histologi− cal examination of the rectal mass showed endometrial glands (arrow head) and surrounding stroma (arrow). Figure 2 Grossly, the mass was found to be composed of multiple hemorrhag− ic grayish polyps and was attached to the rectal wall. Figure 1 Colonoscopic view showing a large, ulcerating polypoid mass that was ob− structing the lumen. U C T N Unusualcasesandtechnicalnotes E48 This document was downloaded for personal use only. Unauthorized distribution is strictly prohibited. Cho YJ et al. Rectal endometriosis mimicking a large polypoid rectal cancer /C180Endoscopy 2006; 38: E48/C177E49 Y. J. Cho, Y. T. Jeen, Y. S. Kim, H. J. Chun, S. H. Um, C. D. Kim, H. S. Ryu Department of Internal Medicine, Institute of Digestive Disease and Nutrition, Korea University College of Medicine, Seoul, Korea. References 1 Olive DL, Schwartz LB. Endometriosis. N Eng J Med 1993; 328: 1759 /C1771769 2 Jatan AK, Solomon MJ, Young J et al. Laparo− scopic management of rectal endometriosis. Dis Colon Rectum 2005; 49: 1/C1776 3 Yantiss RK, Clement PB, Young RH. Endome− triosis of the intestinal tract: a study of 44 cases of a disease that may cause diverse challenges in clinical and pathologic evalua− tion. Am J Surg Pathol 2001; 25: 445 /C177454 4 Parker RL, Dadmanesh F, Young RH et al. Polypoid endometriosis: a clinicopathologic analysis of 24 cases and a review of the lit− erature. Am J Surg Pathol 2004; 28: 285 /C177 297 5 Paksoy M, Karabicak I, Ayan F et al. Intestinal obstruction due to rectal endometriosis. Mt Sinai J Med 2005; 72: 405 /C177408 Corresponding Author Y. T. Jeen, M. D. Department of Internal Medicine Institute of Digestive Disease and Nutrition Korea University College of Medicine 126−1 Anam−dong 5−ga, Seongbuk−gu Seoul 136−705 Korea Fax: +82−2−953−1943 E−mail: [email protected] U C T N Unusualcasesandtechnicalnotes E49 This document was downloaded for personal use only. Unauthorized distribution is strictly prohibited.