Sclerosing Mesenteritis Masquerading as a Small Bowel Mesentery Neoplasm

There are less than 300 cases that have been reported in the literature, mostly as case reports and small case series.1, 2 Sclerosing mesenteritis has a male predominance with a peak in the fifth and sixth decades.1 What makes this disease unique and difficult to diagnosis is its combination of vague clinical symptoms in combination with varied histological findings: fat necrosis, inflammatory cells, and fibrosis. In one study looking at mesenteric panniculitis specifically, characteristic findings included a soft tissue mass at the root of the mesentery, engulfment of superior mesenteric vessels without vascular involvement, and no evidence of the mass invading into surrounding bowel loops.3 Other findings include increased density of the mesenteric fat,1 preservation of the fat around the mesenteric vessels-the "fat ring sign"7, 8-multiple mesenteric lymph nodes,1,7 and a tumoral pseudocapsule,7 yet imaging alone makes it difficult to differentiate sclerosing mesenteritis from neoplastic entities such as lymphoma, carcinoid, and desmoid tumors.