S1881 Colonic Intussusception From a Necrotic Giant Lipoma

Abstract

Introduction: Lipomas are the most common benign subepithelial lesions (SEL) of the colon. They usually originate in the submucosa, however, could rarely be found within muscularis propria or subserosa. Although usually asymptomatic, lipomas can become symptomatic depending on their size and/or location. Herein we present a case of colonic intussusception secondary to a necrotic giant lipoma. Case description/methods: Patient is a 58 year old woman with past medical history of uncontrolled hypertension resulting in two cerebrovascular accidents without residual deficits (currently on clopidogrel) and uncontrolled insulin dependent diabetes type 2 with nephropathy resulting in stage 5 chronic kidney disease leading to iron deficiency anemia (IDA) who presented to ambulatory surgery unit for colonoscopy for further evaluation of IDA. Colonoscopy revealed a 5 cm nearly obstructing ulcerated and necrotic SEL in distal transverse colon. Procedure was complicated by transient desaturation and patient underwent post-procedural computerized tomography (CT) scan to rule aspiration pneumonia as patient was found to have a pieces of ginseng root within the oral cavity. CT scan revealed a 4.8 cm predominantly fatty mass-like lesion at splenic flexure with edematous fat and mild circumferential thickening of wall of proximal descending colon possibly suggesting colocolic intussusception without evidence of bowel obstruction. The patient was admitted to surgical service and taken to the operating room for laparoscopic left hemicolectomy. Pathology revealed a partially necrotic submucosal lipoma with acute inflammation, fat necrosis, ulceration and granulation tissue. Discussion: Colonic lipoma leading to intussusception is a rare complication of otherwise benign SEL. They are typically asymptomatic but can present with obstruction, bleeding, intussusception, and/or abdominal pain. CT scan is the preferred imaging modality for diagnosing aforementioned complications. The differential diagnosis for incidental lesions identified on imaging includes malignancy, large pedunculated polyps or liposarcomas. Management for symptomatic colonic lipomas can be either endoscopic or surgical. Size, location and presenting symptoms are the determining factors for deciding on type of management. Endoscopic ligation (“Loop-And-Let-Go”) technique was contemplated, however, due to finding of intussusception and the fact that patient had to resume clopidogrel, a decision was made to proceed with surgical resection.Figure 1.: A. Image from CT scan revealing a mass in the colon B. Imaging from colonoscopy depicting large lesion nearly obstructing with intussusception C. Microscopic Appearance: Necrotic mucosa and fat globules with foamy macrophages consistent with necrotic lipoma.