[Mesenteric panniculitis]

Mesenteric panniculitis is a nonspecific inflammatory process affecting the fatty tissue at the root of the mesentery. This term is also used to describe the clinical and imaging findings in this disorder. Mesenteric panniculitis can be a misleading term: it is commonly misused to design an increased density of the mesentery without prejudice regarding the etiology. Pain is the main clinical symptom. Half of the patients are asymptomatic. There is a palpable mass in half of cases. Laboratory tests sometimes reveal an acute phase reaction of varying intensity. Mesenteric panniculitis is suspected when CT scan shows increased density of the mesenteric fat. Nevertheless, only histological examination could establish the diagnosis. Histologic examination may reveal various stages: lipodystrophy (the first stage when fat necrosis is predominant), mesenteric panniculitis (a majority of infiltrating lymphocytes), sclerosing mesenteritis (the end stage when fibrosis is predominant). Histopathologic differential diagnoses are lymphomas, lipomas, liposarcomas that can mimic mesenteric panniculitis on CT scan. Mesenteric panniculitis is associated with various diseases, especially with intra-abdominal inflammatory process. It also can be idiopathic. Rare complications can occur with vascular or digestive tract compressions. Empirical treatment is only useful in symptomatic patients. Colchicine, corticosteroids or immunosuppressive agents can be used. The only interest of surgery is the histological confirmation of the diagnosis. A better understanding of the pathophysiology of the immunoregulatory functions of adipose tissue will improve mesenteric panniculitis management.