A Case of Solitary Fibrous Tumor Originating From Mesentery of the Sigmoid Colon and Rectum

Abstract

A 59-year-old woman having initially presented to a clinic with abdominal distension was referred to the gynecology department in our hospital for the treatment of a pelvic tumor Abdominal contrast-enhanced computed tomography (CT) and magnetic resonance imaging (MRI) revealed a lobulated pelvic tumor measuring 20cm in size that showed internal heterogeneous enhancement, indicating necrotic or cystic lesions. The submucosal vein of the sigmoid colon and the inferior mesenteric vein were both markedly dilated. A diagnosis of a pelvic tumor originating from the mesentery of the sigmoid colon was made, and the tumor was surgically removed. Gross inspection of the specimen revealed a solid multinodular tumor, 20×15×7cm in size and weighing 1,740g. Histologically, the tumor was composed of spindle-shaped cells with vessel growth, which were immunohistochemically positive for CD34, vimentin, and Bcl-2, and negative for c-kit, desmin, and S-100. The final diagnosis was that of a solitary fibrous tumor (SFT). The patient has been disease-free for 15 months following the surgery.

SFT originating from the mesentery of the sigmoid colon and rectum is a rare tumor, with only 31 cases, including our own, reported in the literature to date. Although the incidence of malignant SFT is low, complete resection and long-term follow-up is very important.