A Difficult-to-diagnose Case of Sigmoid Mesocolon Endometriosis

Abstract

A 73-year-old woman had been examined at another medical institution for abdominal pain. Cholecystitis and cholangitis were diagnosed, and her symptoms improved after endoscopic retrograde biliary drainage. Cholecystectomy was recommended, and since the patient expressed the wish to undergo the operation at our hospital, she was referred to our department. Abdominal plain computed tomography (CT) conducted during preoperative testing showed a nodule at the sigmoid mesocolon with associated tightening of the surrounding adipose tissue. Similar findings were also evident on magnetic resonance imaging, and fluorodeoxyglucose uptake was apparent on positron emission tomography CT. In light of the possibility of mesenteric carcinoid or other malignancy, laparoscopic sigmoid colectomy (with D3 lymph node dissection) was carried out at the same time as laparoscopic cholecystectomy. Pathological testing of the resected specimen showed estrogen receptor and progesterone receptor expression, and sigmoid mesocolon endometriosis was diagnosed. It is extremely rare for endometriosis lesions to arise in the mesentery. A case of endometriosis in the sigmoid mesocolon is presented, together with a discussion of the literature.