Intraoperative Detection of Rectosigmoid Endometriosis.

A 42-year-old with a history of total hysterectomy, bilateral salpingectomy, and right oophorectomy with another provider for the treatment of adenomyosis and endometrioma 2 years prior presented with cyclical hematochezia. Postoperatively, chronic pelvic pain improved; however, cyclical hematochezia and rectal passage of mucus developed. Colonoscopy showed a 3 to 4 cm nodule 12 cm from the anal verge, which is concerning in patients with endometriosis. Sagittal high resolution T2-weighted imaging on magnetic resonance imaging (MRI) showed curvilinear T2 hypointense marked thickening corresponding to deep infiltrating endometriosis involving the anterior sigmoid, classically described as a “mushroom cap.” This finding reflects transmural involvement of the sigmoid colon located approximately 15 cm from the anal verge. The patient subsequently underwent excision of endometriosis. Intraoperatively, a nodule measuring 3 cm was visualized and found to involve >50% of the bowel circumference (Fig. 1). Low anterior rectosigmoid resection with primary reanastomosis was completed. Specimen appearance (Fig. 2) was concordant with MRI results (Fig. 3), and pathology confirmed endometriosis. Fig. 2Specimen appearance. View Large Image Figure Viewer Download Hi-res image Fig. 3Preoperative MRI demonstrating “mushroom cap” sign. View Large Image Figure Viewer Download Hi-res image