A Resected Huge Schwannoma of the Sigmoid Mesentery

Abstract

The patient was a 77-year-old man who was referred to our hospital for close examination and treatment because a large pelvic mass was incidentally detected on abdominal computed tomography (CT) performed during a visit to his previous doctor for a urinary tract infection. Contrast-enhanced CT and magnetic resonance imaging (MRI) of the abdomen showed a lobulated mass in the midline of the pelvis, which was suspected to be a sigmoid mesenteric tumor, and it was decided to remove the tumor for both diagnosis and treatment. The patient underwent abdominal high-level anterior resection and removal of the mesenteric tumor. The patient was discharged home on the 9th postoperative day without complications. There was no recurrence of the tumor. Histopathologically, immunostaining was positive for S100 protein and negative for CD34, c-kit, and α-SMA, and a diagnosis of schwannoma was made. Sigmoid mesenteric schwannoma is rare, and this case is reported along with some discussion of the literature.