The differential diagnosis for a large cecal mass includes various malignant and benign tumors. We present a case of a young female that underwent a right hemicolectomy for a cecal mass concerning for malignancy. The final pathology revealed two large endometriomas located in the terminal ileum and cecum.

A pelvic MRI performed in evaluation of infertility and cyclical pelvic pain revealed a large mass (> 2.4 cm) obstructing the appendix in a 32 year old female. The patient reported intermittent right lower quadrant fullness and a 10 pound weight loss over a 6 month period. Colonoscopy was notable for a prominent ileocecal valve; histological evaluation illustrated benign mucosal tissue. Laboratory studies revealed an elevated chromogranin-A level with normal CEA and 5-HIAA values. An Octreoscan was unrevealing. Due to concern for malignancy, a laparoscopic oncologic right colectomy was performed as highlighted in the video.

Pathological examination of the right colectomy specimen revealed a massively dilated appendix and two giant endometriomas, involving the cecum (3.0 cm) and terminal ileum (4.0 cm). There was no evidence of malignancy. The patient was discharged on post operative day 3 following an unremarkable hospital stay.

Gastrointestinal endometriomas, although rare, should be included in the differential diagnosis of premenopausal females presenting with an extraluminal intestinal mass. Laparoscopic resection, for symptoms or concern for malignancy, seems to be safe and appears to provide the surgeon with the greatest treatment flexibility.