Intestinal Endometriosis Mimicking Carcinoma of Rectum and Sigmoid Colon: A Report of Five Cases

CASE REPORT in all five patients and revealed an ulcerofungating mass in two cases (Fig. 1), mucosal protrusion without mucosal abnormality in one case, luminal narrowing with extrinsic compression in one case and a polypoid mass in one case. Colonoscopic biopsy was performed in three out of the five patients. The biopsies showed chronic inflammation in two cases and a normal finding in one case. A computed tomo- graphy (CT) scan was also performed in all patients, and revealed colonic and rectal wall thickening in two cases and submucosal tumor suggesting GIST in one case. How- ever, no masses were identified in two cases (Table 1). Magnetic resonance imaging (MRI) was performed in cases with rectal involvement, and the findings were not different from those of CT. PET scan was performed in case 5 and suggested malignant uptake in the rectum (not documented in Table 1). All patients underwent dissection of paracolic and intermediate lymph nodes, as well as lymph nodes in the root of the inferior mesenteric artery. The laparotomy was done by low midline incision in three patients and by laparoscopic surgery in two patients. Two anterior resec- tions and three low anterior resections were performed. We did not perform a frozen section at the time of the operation because the operative finding seemed to be a malignant tumor, even though a previous colonoscopic biopsy did not reveal malignancy. However, all surgical specimens were indicated endometriosis according to final pathology reports (Fig. 2). The symptoms of intestinal endometriosis vary according to the site of involvement. 4 Rectosigmoid endometriosis can cause alterations in bowel habit and bleeding that resemble symptoms of colorectal cancer. Colonic endome- triosis may manifest as an acute abdomen resulting from perforation and associated peritonitis. Small bowel involvement may produce non-specific symptoms such as recurrent abdominal pain and bloating, but terminal ileal involvement frequently results in the development of acute or chronic small bowel obstruction. The gold standard diagnostic procedure for intestinal endometriosis is laparoscopy or laparotomy. The laparos- copic procedure is more useful for a complete and accurate evaluation of both the genital and intestinal tracts. More- Intestinal Endometriosis Mimicking Carcinoma Yonsei Med J http://www.eymj.org Volume 50 Number 5 October 2009733 Fig. 1. (A) Colonoscopic finding. Ulcerofungating mass 8 cm above the anal verge is suspicious for rectal cancer. (B) CT scan of the pelvis shows rectal mass with perirectal tumor infiltration (Case 2). A B Fig. 2.(A) Gross specimen. The polypoid mass is seen on the laparoscopically resected rectum. (B) The mass was revealed as endometriosis, which is composed of stroma and glands of endometrium, upon microscopic analysis (Hematoxylin Eosin ×100) (Case 5). A B

over, surgical intervention of genital endometriosis may be performed during laparoscopy. Thus, diagnostic laparos- copy is indicated in patients with suspicion of intestinal endometriosis. Intestinal endometriosis often presents as a submucosal tumor or luminal stenosis because it mainly involves the muscularis propria and subserosa or mesentery. 5 In the case of mucosal involvement, a bleeding, polypoid mass may be present. These clinical manifestations are some- times difficult to distinguish from malignancy, inflam- matory bowel disease, or ischemic colitis. 5,6 Radiologic and endoscopic examinations are essential for the diagnosis of intestinal endometriosis, which may be confused with malignancy, based on colonoscopy and CT scan, particu- larly in patients with mucosal involvement. 7 MRI seems to be the most sensitive imaging technique for intestinal endometriosis. 8 However, these evaluations are not diag- nostic. The purpose of treatment of intestinal endometriosis is elimination of symptoms, removal of as much endometrial tissue as possible and cessation of disease progression. Physicians should consider the patient’s age and desire to maintain fertility and the severity and complications of the disease. 7 Treatment options consist of medical and surgical treatment. In severe cases, combined treatment may be considered. The medications used in the treatment of endometriosis are danazol, high-dose progestins, and GnRH agonists, all of which have equivalent efficacy. 9 Most decisions for surgical intervention depend on the severity of symptoms and response to medical treatment. Infertility is one of the most important symptoms to consi- der for operative intervention. Intestinal endometriosis may be encountered unexpectedly during abdominal exploration. If the diagnosis of endometriosis can be confirmed by frozen biopsy and there is no significant obstruction, the optimal treatment choice is to close the abdomen and consider definitive treatment of the patient after bowel preparation and possible medical therapy. Recently, treatment outcomes for endometriosis have improved with the development of laparoscopic surgical skills and medical hormonal therapy. 10 We report five cases of intestinal endometriosis misdia- gnosed as colorectal cancer. The symptoms of hematochezia and abdominal pain in combination with colonoscopic and radiologic findings were suggestive of malignancy alth- ough the colonoscopic biopsies were not confirmative. We admit that preoperative evaluations were not fully examined, and close follow-up may be helpful to avoid false positives. The addition of diagnostic laparoscopy may be a reasonable option. However, surgical treatment should be considered when the differential diagnosis of malignancy is not determined or medically intractable symptoms are present. In the current case report, gastrointestinal symptoms or colonoscopic and radiologic findings resulted in the decision for surgery, and subsequent surgical specimens revealed intestinal endometriosis. Jin Soo Kim, et al. Yonsei Med J http://www.eymj.org Volume 50 Number 5 October 2009734 Table 1.Clinical Characteristics of Five Patients with Intestinal Endometriosis Mimicking Carcinoma of Rectum and Sigmoid Colon Presenting Colonoscopic Involved Preoperative Operative Pelvic organCase Age symptom Parity finding/biopsy CT finding intestine impression treatment involvement& sign Ulcero-fungating Colonic Sigmoid Sigmoid colon1 41 Hematochezia G3P2 mass / chronic wall colon cancer AR Lt. ovary inflammation thickening Ulcero-fungating Rectal 2 27 Hematochezia G1P0 mass / within wall Rectum Rectal cancer LAR None normal thickening Mucosal Submucosal Laparoscopic 3 46 None G2P1 protrusion / not tumor Rectum GIST LAR None performed Abdominal pain, Luminal Sigmoid Sigmoid colon44 7 obstipation G2P2 narrowing / NED colon cancer AR None not performed Polypoid mass Rectal Laparoscopic5 38 None G0 / chronic NED Rectum cancer LAR None inflammation AR, anterior resection; LAR, low anterior resection; GIST, gastrointestinal stromal tumor; NED, no evidence of disease. In conclusion, intestinal endometriosis is a relatively rare disease and is difficult to differentiate from malignancy, when based on clinical symptoms, endoscopic procedure, and radiologic findings. We suggest to consider also intes- tinal endometriosis in reproductive women presenting with gastrointestinal symptoms and an intestinal mass of unkn- own origin. This study was supported by grants of the Korea Healthcare technology R&D project, Ministry for Health, Welfare & Family Affairs, Republic of Korea (A040001, A040151). 1. Olive DL, Schwartz LB. Endometriosis. N Engl J Med 1993; 328:1759-69. 2. Croom RD 3rd, Donovan ML, Schwesinger WH. Intestinal endometriosis. Am J Surg 1984;148:660-7. 3. Miller LS, Barbarevech C, Friedman LS. Less frequent causes of lower gastrointestinal bleeding. Gastroenterol Clin North Am 1994;23:21-52. 4. Giudice LC, Kao LC. Endometriosis. Lancet 2004;364:1789-99. 5. Barclay RL, Simon JB, Vanner SJ, Hurlbut DJ, Jeffrey JF. Rectal passage of intestinal endometriosis. Dig Dis Sci 2001;46:1963-7. 6. Langlois NE, Park KG, Keenan RA. Mucosal changes in the large bowel with endometriosis: a possible cause of misdiagnosis of colitis? Hum Pathol 1994;25:1030-4. 7. Dimoulios P, Koutroubakis IE, Tzardi M, Antoniou P, Matal- liotakis IM, Kouroumalis EA. A case of sigmoid endometriosis difficult to differentiate from colon cancer. BMC Gastroenterol 2003;3:18. 8. Brosens I, Puttemans P, Campo R, Gordts S, Brosens J. Non- invasive methods of diagnosis of endometriosis. Curr Opin Obstet Gynecol 2003;15:519-22. 9. Mahutte NG, Arici A. Medical management of endometriosis- associated pain. Obstet Gynecol Clin North Am 2003;30:133-50. 10. Emmanuel KR, Davis C. Outcomes and treatment options in rectovaginal endometriosis. Curr Opin Obstet Gynecol 2005; 17:399-402. Intestinal Endometriosis Mimicking Carcinoma Yonsei Med J http://www.eymj.org Volume 50 Number 5 October 2009735

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