Colonic lipomas and liposarcomas

Abstract

Gastrointestinal lipomas are benign rare adipose tissue tumors, most frequently seen in the submucosal layer of the colon. They are often small and asymptomatic, although larger tumors may become symptomatic and pose a diagnostic challenge. Colonoscopy is reliable for the diagnosis of a typical lipoma, but the endoscopic appearances may be worrisome, especially when the lesion is atypical, ulcerated, or bleeding. CT and MRI may reveal the signal and uptake of adipose tissue but a confident diagnosis may not be possible. Histology may be not diagnostic due to the superficial nature of mucosal biopsies. Lipomas can be removed endoscopically, but an increased risk of perforation is associated with polypectomy of larger lesions (Shibata et al., 200826). Surgical intervention is the recommended modality for lipomas more than 4cm in size, lipomas with sessile appearance or involvement of the muscular layer or serosa, unclear preoperative diagnosis, symptomatic lesions, and failed endoscopic removal (Jiang et al., 200715). Segmental resection is the procedure of choice for suspicious lesions. Liposarcoma of the colon is extremely rare and requires the presence of lipoblasts. Only a few cases of primary liposarcoma of the colon have been reported in the literature. The collection of a larger number of cases is needed for the determination of guidelines for the management of this rare tumor.