A Case of Leiomyosarcoma of the Sigmoid Colon Presenting with Intussusception

Abstract

An 88-year-old woman visited the hospital with bloody stool. Hematological investigation showed anemia, and colonoscopy revealed a type 1 tumor in the sigmoid colon. Abdominal CT detected intussusception with a mass in the sigmoid colon. Endoscopic pneumatic reduction was not successful in reducing the intussusception. We performed open sigmoid colon resection. Macroscopic examination revealed a large type 1 tumor of size 10×5×3 cm in the sigmoid colon. Pathological examination showed spindle-shaped atypical cells in the tumor. There was hyperplasia with a complex sequence. Immunostaining showed c-kit-negative, CD-34-negative, α-SMA-positive, and caldesmon-positive areas, and the patient was diagnosed with sigmoid colon leiomyosarcoma. The postoperative course was good. No adjuvant chemotherapy was administered, and the patient has been free of leiomyosarcoma recurrence 9 months after the operation.