Colonic intussusception caused by giant lipoma: a rare cause of bowel obstruction

[Introduction]: Colonic lipomas are extremely uncommon benign non-epithelial tumours, with an incidence ranging between 0.035 and 4.4%. Although lipomas are most frequently asymptomatic, when colonic lipomas exceed 2-cm width, they may present symptoms such as constipation, abdominal pain or rectal bleeding. Most colonic lipomas typically occur in middle-aged women and are located in the ascending colon and the caecum, while occurrence in other parts of the colon and rectum is infrequent. We present a rare case of bowel obstruction secondary to colonic intussusception caused by a giant lipoma.
[Case report]: A 55-year-old man presented with a longstanding history of intermittent abdominal pain and constipation. Physical examination was unremarkable. Colonoscopy revealed a smooth surface, submucosal mass which occupied the entire colonic lumen (diameter 50 mm) and there was also ulceration of adjacent mucosa. Abdominal CT-scan showed a colonic mass located at the splenic flexure, which caused colo-colic intussusception (Figs. 1, 2 and 3). The biopsy was inconclusive. The patient underwent laparoscopic segmentary colectomy and postoperative course was uncomplicated. Histological analysis revealed a 5-cm ulcerated lipoma (Figs. 4 and 5) affecting 60% of bowel circumference. The molecular study, using fluorescent in situ hybridization (FISH) showed no MDM2 gene amplification. At 6-month follow-up, the patient reported normal bowel habit.
[Conclusion]: Although most colonic lipomas are asymptomatic, large ones may require surgical treatment since they are associated with complications. The complete removal of the lipoma will condition the prognosis. In these cases, laparoscopic approach is a safe alternative that offers the benefits of early postoperative recovery.