Unroofing Technique for Endoscopic Resection of a Large Colonic Lipoma

A 77-year-old man presented with repeated episodes of melena. He had a medical history of hypertension, atrial fibrillation and cardiogenic brain infarction and took medications, i.e. an antiplatelet agent. Laboratory data revealed iron deficiency anemia. Colonoscopy revealed a yellowish smooth submucosal tumor, 50 mm in diameter, on the Bauhin valve. The lesion was soft and compressible. The overlying mucosa was erosive. CT scan showed a uniform mass with very low density in the ascending colon, corresponding to the above-detected lesion. The clinical diagnosis of colonic lipoma was established. Using a 25 mm electrocautery snare (Olympus, Tokyo, Japan), we transected the upper portion of the mass to unroof the lesion. The mucosa layer was thick and hard. Fat tissue was observed extruding from the cut surface, consistent with the diagnostic hypothesis. After dissecting the overlying mucosa on the anal side by means of an IT knife (Olympus) in order to completely extrude the mass, the fat tissue was further exposed. It took about 26 min to perform the whole procedure. There were no procedure-related complications. Macroscopically, the resected lesion was a yellow solid tumor, 1.6 × 1.5 × 0.7 cm in diameter. Histopathologic examination of the excised specimen confirmed the diagnosis of a lipoma. The clinical course was uneventful. A follow-up endoscopy 1 month later showed a scarred mucosa at the resection site. Similarly, a follow-up CT scan 2 months later revealed no evidence of residual lipoma. The unroofing technique is safe, easy and suitable for the treatment of large lipomas.