{"paper_id":"d0de8065-6745-4295-91a1-341b653b68da","body_text":"Introduction:\nDeeply Infiltrating Endometriosis (DIE) is defined as implantation of endometrial tissue outside of the uterus at least 5 mm beneath the peritoneum. While anywhere between 3.8-37% of patients with endometriosis may have bowel involvement, infiltration of endometrial tissue into the bowel mucosa is quite rare. In a systematic review of patients who underwent bowel resection for endometriosis, the mucosa was involved in only 6.4%. We present the case of a patient who underwent colonoscopy for rectal bleeding ultimately found to be due to intraluminal endometriosis of the sigmoid colon.\nCase Description/Methods:\nA 43-year-old female with a history of endometriosis and prior sigmoid polypectomy presented for surveillance colonoscopy in the setting of bright red blood per rectum and a known sigmoid adenoma. Colonoscopy revealed a scar in the sigmoid colon overlaid with residual polypoid tissue (Figure 1). Eleview was used to raise the lesion and piecemeal mucosal resection was performed using a snare. Following resection and retrieval of tissue, three hemostatic clips were successfully placed and the patient was discharged home without complications. Immunohistochemical analysis revealed glandular cells strongly and diffusely positive for estrogen receptor (ER) and paired-box gene 8 (PAX-8), suggestive of endometrium. There were numerous areas of intestinal tissue highlighted by the CDX2 marker interspersed with stromal cells positive for ER and neprilysin, which together confirmed the diagnosis of endometriosis with intestinal metaplasia.\nDiscussion:\nIntraluminal colonic endometriosis is a rare form of DIE that may present as abdominal pain and rectal bleeding in the pre-menopausal patient. While colonoscopy may help visualize the mass, it is nearly impossible to distinguish endometrial tissue from intestinal metaplasia, and definitive diagnosis requires positive immunohistochemical staining. While symptoms may be mitigated with estrogen-progestin contraceptives and nonsteroidal anti-inflammatory drugs, curative measures have historically involved rectosigmoid resection.\nReferences\n1.\nRemorgida, et al., Bowel Endometriosis: Presentation, Diagnosis, and Treatment. Obstetrical & Gynecological Survey, July 2007, 62(7), 461-470.2.\nMeuleman, et al., Surgical Treatment of Deeply Infiltrating Endometriosis with Colorectal Involvement.Human Reproduction Update, 2011, 17(3), 311-326.","source_license":"CC0","license_restricted":false}