An incidental infiltrating colonic lesion found during colonoscopy in a woman in her 30s

We describe a case of a 38-year-old female who presented with severe pelvic pain and constipation for several months. She complained of prolonged and painful menses since menarche. She denied weight loss and a family history of colorectal cancer and/or inflammatory bowel disease. She was taking no medications and had never had surgery in the past. She was referred for a colonoscopy. A 3 × 2 × 3 cm intraluminal mass in the sigmoid colon was found (Fig. 1). Histopathological examination confirmed endometriosis.

Endometriosis was noted in the lumen of our patient's sigmoid colon. She underwent MRI scanning which revealed endometriosis in the Pouch of Douglas and through the wall of her sigmoid colon. She underwent an elective laparoscopic hysterectomy, excision of multiple endometrial deposits and anterior resection of the sigmoid and upper rectum.

Endometriosis is the presence of endometrial tissue found in an abnormal, extra-uterine location.¹ It is typically isolated to pelvic organs; however, in up to 12% of cases, it extends to and infiltrates the intestine.² Most commonly, the sigmoid colon and rectum are affected by endometrial implants. These patients typically present with a change in bowel habit (e.g., constipation), pelvic pain and/or infertility.¹ Involvement of more proximal bowel is relatively rare.³

Colon and rectal endometriosis is typically managed mainly laparoscopically.⁴ It presents a challenge to the surgeon as it can be complicated by dense adhesive disease and deep pelvic involvement, increasing the risk of intra- and post-operative complications.⁵ Complications occur in up to 22% of cases.^{3, 5} Additionally, preoperative imaging including CT and MRI may not correlate with intraoperative findings. Symptom resolution is variable. Sustained pain relief at 1 year is found in up to 94% of patients. Reported symptom recurrence at 2–5 years is 4%–54%.³

Consent for use of this image and details has been obtained from the patient.

Author contributions

Tara M. Connelly: Conceptualization; funding acquisition; investigation; methodology; project administration; supervision; validation; writing – original draft; writing – review and editing. Ju Yong Cheong: Conceptualization; formal analysis; funding acquisition; investigation; methodology; supervision; visualization; writing – original draft; writing – review and editing. Hermann Kessler: Conceptualization; formal analysis; funding acquisition; investigation; methodology; project administration; visualization; writing – original draft; writing – review and editing. Eddy P. Lincango: Conceptualization; formal analysis; funding acquisition; investigation; methodology; project administration; supervision; visualization; writing – original draft; writing – review and editing.