Intestinal endometriosis in a 36-year-old woman

E960 CMAJ | AUGUST 17, 2020 | VOLUME 192 | ISSUE 33 © 2020 Joule Inc. or its licensors A 36-year-old woman presented to the emergency depart- ment with a 9-month history of abdominal pain accom- panied by rectal bleeding during menstruation. She was otherwise well. Her pelvic and rectovaginal examination, as well as findings on transvaginal ultrasound, were unremarkable. T2-weighted magnetic resonance imaging (MRI) showed a hypo - intense wall thickening in the sigmoid colon. We suspected endo- metriosis and our differential diagnosis included inflammatory bowel disease and cancer. Colonoscopy showed a 30-mm submu- cosal lesion with a red, nodular surface in the sigmoid colon (Figure 1A). Pathologic examination of biopsy specimens was nonspecific. Subsequently, biopsies performed during a second colonoscopy just before the patient’s menstrual phase showed an endometriotic gland and stroma, positive for estrogen receptor (Figure 1B). We diagnosed intestinal endometriosis. Our patient preferred to avoid long-term hormone therapy and accepted the risk associated with laparoscopic sigmoidectomy. Laparoscopic exploration showed no other endometriotic implants. Intestinal endometriosis occurs in 5%–15% of women with endometriosis, and as was the case with our patient, about 20% of women with intestinal endometriosis do not have pelvic endo- metriosis.1 The rectosigmoid colon is involved in 3 out of 4 patients with intestinal endometriosis. Although MRI and transvaginal ultra- sound are sensitive diagnostic modalities for intestinal endometri- osis, definitive diagnosis requires a biopsy. Endoscopic biopsies frequently yield insufficient tissue because the mucosal involve- ment is sparse.2 We performed endoscopic biopsies just before the menstrual phase, when endometriotic tissue is at its peak. First-line treatment of endometriosis is hormonal, but surgery may be per- formed for severe intestinal stenosis or to accommodate a patient’s preference. The rate of recurrence after surgery is about 10%.3 References 1. Rossini LG, Ribeiro PA, Rodrigues FC, et al. Transrectal ultrasound — Techniques and outcomes in the management of intestinal endometriosis. Endosc Ultra- sound 2012;1:23-35. 2. Bong JW, Yu CS, Lee JL, et al. Intestinal endometriosis: diagnostic ambiguities and surgical outcomes. World J Clin Cases 2019;7:441-51. 3. Meuleman C, Tomassetti C, D’Hoore A, et al. Surgical treatment of deeply infiltrating endometriosis with colorectal involvement. Hum Reprod Update 2011;17:311-26. PRACTICE | CLINICAL IMAGES Intestinal endometriosis in a 36-year-old woman Yasuhiko Hamada MD PhD, Kyosuke Tanaka MD PhD n Cite as: CMAJ 2020 August 17;192:E960. doi: 10.1503/cmaj.191471 Figure 1: (A) Endoscopy image showing reddish nodules (arrows) atop a 30 mm submucosal lesion in the sigmoid colon of a 36-year-old woman. (B) Biopsy image obtained just before the patient’s menstrual phase, showing a gland and stroma of endometrium (arrow) (hematoxylin and eosin stain; original magnification x100. Competing interests: None declared. This article has been peer reviewed. The authors have obtained patient consent. Affiliations: Departments of Gastroenterology and Hepatology (Hamada), and Endoscopic Medicine (Tanaka), Mie University Hospi- tal, Tsu, Japan Correspondence to: Yasuhiko Hamada, [email protected]