Laparoscopic resection for a mesenteric lipoma of the ascending colon: a case report

Introduction: Lipomas are benign tumors that commonly occur in the arms, legs, and trunk of adults. Mesenteric lipomas are rare, particularly in the mesocolon. Case presentation: A 32-year-old puerperal woman developed abdominal pain 1 day after a Cesarean section. Computed tomography revealed a 10-cm, poorly enhanced, smoothly contoured mass dorsal to the ascending colon and ventral to the right kidney. Magnetic resonance imaging showed a homogeneous mass with clear borders and a thin peripheral capsule. A retroperitoneal sarcoma and well-differentiated liposarcoma were suspected. The mass was supplied by the superior mesenteric artery; therefore, laparoscopic ileocecal resection was performed. A histopathological examination revealed a 10 × 8 cm mesenteric lipoma. The patient recovered well and was discharged. Discussion: Mesenteric lipomas are uncommon and mostly arise from mobile intestinal segments, including the small intestine, transverse colon, and sigmoid colon. Since the ascending colon is retroperitoneally fixed, lipomas from this region are exceptionally rare and challenging to diagnose preoperatively. Mesenteric lipomas may mimic retroperitoneal tumors, particularly well-differentiated liposarcomas; therefore, a careful assessment of anatomical relationships and vascular supply is essential. When malignancy cannot be excluded, complete surgical resection allows for diagnostic confirmation and therapeutic management. Laparoscopic surgery provides a minimally invasive approach and safe tumor removal. In this case, laparoscopic ileocecal resection enabled a definitive diagnosis and successful treatment. Conclusion: Mesenteric lipomas arise from mobile intestinal segments, such as the small intestine, transverse colon, and sigmoid colon. Mesenteric lipomas in the ascending colon have not been described in the English or Japanese literature.