Rectal endometriosis mimicking malignant rectal mass

Introduction: Endometriosis is a relatively frequent disease in fertile women. It has been reported to occur in 3 to 19% of menstruating women. The intestine is involved in 12–37% of cases. The sigmoid colon is the most commonly affected segment, followed by the rectum; these two sites together account for 70% of intestinal cases. We report a unique case of rectal endometriosis mimicking malignant rectal mass.