Why Is My Gastric Band Patient Still Gaining Weight?

Esther H Cha, MD¹, Shadi Al-Bahri, MD², Michel M Murr, MD². ¹Medstar Union Memorial Hospital, ²University of South Florida – Tampa General Hospital

Introduction: Lipomas are well-defined, encapsulated benign tumor of mature adipose tissue commonly located in the subdermal tissues of the trunk and extremities. However, primary intestinal mesenteric lipomas are rare. They are usually asymptomatic but a few can cause partial intestinal obstruction and even rarer to cause volvulus or complete intestinal obstruction due to torsion. We present a case of a male patient who previously underwent a successful laparoscopic adjustable band presenting with a progressively enlarging palpable abdominal mass and found to be a giant mesenteric lipoma.

Case Presentation: A 52 year-old male with a history of morbid obesity who underwent a laparoscopic adjustable gastric band 8 years ago presented with complaints of recent weight gain and abdominal fullness despite initial success with his band. Workup revealed a 24 cm tumor appearing to be mesenteric in origin on computed tomography (CT). An exploratory laparotomy was performed, and the mesenteric mass was removed in its entirety, measuring 24 x 18 cm and weighing 4.5 lbs. Its blood supply was derived from a single large vessel that appeared to arise from the epiploica of the sigmoid colon. Histopathology showed signs of fat necrosis within the core of the essentially giant lipoma. The patient tolerated the procedure well; his diet was resumed upon return of bowel function and was discharged on post-operative day 3.

Discussion: A lipoma is a slow-growing benign mesenchymal tumor of mature adipose cells. It is commonly found in the subdermal tissues of the trunk and extremities. Primary mesenteric lipoma is rare. Literature review performed by Cha et al. at 2007 showed less than 30 reported cases of mesenteric lipomas. Usually, these benign lesions are asymptomatic but can infrequently cause abdominal discomfort or an acute intestinal obstruction due to volvulus.

On ultrasound and CT, lipomas are homogenous with slight hyperechoic smooth outlines. With larger lipomas, it can compress adjacent tissues or organs and become heterogeneous making them indistinguishable from malignant liposarcoma. Thus, when evaluating a mesenteric mass, other fat attenuation processes should be considered including liposarcoma, lipoblastoma, lymphangiomas and cavitating mesenteric lymph node syndrome.

Conclusion: Mesenteric lipoma is a rare benign tumor of adipose tissue. They can be diagnosed using ultrasonography or CT, showing the mass as a smooth, well-defined homogenous echogenic entity. Complete surgical excision is the main treatment with a good prognosis.