[Relapsing polychondritis and mesenteric panniculitis: apropos of 2 cases]

Relapsing Polychondritis Complicated by Vasculitis of the Omentum

A 78-year-old man presented with bilateral auricular and nasal chondritis and an inner ear disorder. Relapsing polychondritis (RPC) was diagnosed and corticosteroid therapy was initiated. Two years later, he developed abdominal pain and a fever. A contrast-enhanced computed tomography scan showed enhancement of the mesentery and massive ascites. The patient underwent emergency laparotomy, which revealed inflammation and thickening of the omentum. A microscopic examination of the omentum disclosed vasculitis, and corticosteroid and cyclophosphamide pulse therapies were administered. We herein report the first case of RPC complicated by pathologically proven vasculitis of the omentum, clearly indicating an association between the pathogenesis of these two conditions.

Mesenteric panniculitis: an update

In 1924, mesenteric panniculitis was first described in the medical literature by Jura et al. as 'retractile mesenteritis.' It represents a spectrum of disease processes characterized by degeneration, inflammation and scarring of the adipose tissue of the mesentery. The clinical presentations vary according to the stage of the disease and they include abdominal pain, weight loss, nausea and vomiting. Computed tomography findings are usually diagnostic. The gross findings include thickening of the mesentery, mass lesions and adhesion to the surrounding organs. Histologically, there is a chronic inflammatory process involving the adipose tissue with fat necrosis, inflammation and fibrosis. Herein, the authors address the clinicopathological features, course, treatment and pathogenetic mechanisms of mesenteric panniculitis.

[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.

[Etiologic spectrum of mesenteric panniculitis: report of 7 cases]

OBJECTIVE

Mesenteric panniculitis is a rare disorder characterized by nonspecific inflammation and/or necrosis and/or fibrosis in the adipose tissue of the bowel mesentery. Its signification, primary or associated with other diseases, is a subject of controversy.

METHODS

A descriptive and retrospective study of patients with an abdominal CT examination showing features of mesenteric panniculitis and for whom biopsy with immunohistochemical examination was obtained in all cases.

RESULTS

Seven patients were enrolled (4 men and 3 women) with a median age of 62,1 years. None of the patients without an identified etiology had a history of abdominal surgery. An associated disease was identified in 4 cases: breast cancer (1), non-Hodgkin's lymphoma based on peripheric lymph nodes biopsy (2) and cryoglobulinemic vascularitis based on renal biopsy (1). In the 3 remaining cases, isolated mesenteric panniculitis was the only abnormality despite thorough imaging and pathologic investigations.

CONCLUSION

Except an obvious malignancy context or a history of abdominal surgery, a pathologic examination of the mesenteric panniculitis lesions is necessary, especially to eliminate another mesenteric disorder. Mesenteric panniculitis is often associated with lymphoma.