18F-FDG PET/CT Findings in a Patient With IgG4-Related Sclerosing Mesenteritis.

A large mass in the abdomen was revealed by ultrasonography on a 68-year-old woman presenting with abdominal pain and weight loss. To exclude the malignancy, an F-FDG PET/CT was performed, which showed a solitary soft tissue mass with heterogeneous F-FDG avidity at the root of small bowel mesentery. Because of the elevation of inflammatory markers and serum IgG4 level, IgG4-related sclerosing mesenteritis was suspected, which was proved by the subsequent biopsy. The mass gradually shrunk and ultimately disappeared in 6 months after a low-dose steroid therapy.

Surgical management of isolated mesenteric autoimmune disease: addressing the spectrum of IgG4-related disease and sclerosing mesenteritis.

IgG4-related disease (IgG4-RD) is a rare form of autoimmune sclerosing disease, characterised by elevated serum IgG4 and tissue IgG4 levels, specific histopathological findings, multiorgan involvement and adequate response to glucocorticoid treatment. The low incidence and the heterogeneous nature of the disease has made consensus on diagnostic criteria for IgG4-RD difficult. Whether sclerosing mesenteritis (SM) is considered a manifestation of IgG4-RD is strongly debated. We present the case of a patient with a history of rheumatoid arthritis who presented with a calcified abdominal mass. She was found to have an isolated, pedunculated mesenteric mass positive for IgG4 and concurrently elevated serum IgG4 levels. Clinical features did not classify her disease as either SM or IgG4-RD as currently described in consensus statements. Concurrent diagnoses of IgG4-RD, SM and other autoimmune disorders, as well as postoperative recommendations for resected isolated IgG4-positive masses, are discussed.

A case of IgG4-related mesenteritis.

IgG4-related disease is a newly recognized fibroinflammatory condition characterized by tumefaction consisting of fibrosis with dense infiltration of IgG4-positive plasma cells; affecting various organs. A case of IgG4-related sclerosing mesenteritis is reported. A 64-year-old man was admitted to our hospital with a suspected tumor of the small intestine. Abdominal computed tomography demonstrated a 6-cm soft tissue mass in the right lower mesentery compressing the jejunum, which also showed accumulation of fluorodeoxyglucose uptake on fluorine-18 fluorodeoxyglucose positron emission tomography. With a preoperative diagnosis of suspected malignant lymphoma with lymphadenopathy in the mesentery, partial small bowel resection was performed. Macroscopically, a hard mass, including several swollen lymph nodes, was detected in the mesentery. Microscopically, marked fibrosis showing partially storiform pattern, obstructive phlebitis, follicular hyperplasia, and abundant infiltration of IgG4-positive plasma cells were detected. IgG4-related mesenteritis was diagnosed histopathologically, but the serum IgG4 level was 81 mg/dl postoperatively. Five months after the surgery, an 11-cm soft tissue mass involving the left ureter appeared. Histological examination of a biopsy specimen from the retroperitoneal mass showed fibrosis with inflammatory infiltration. Although IgG4-related retroperitoneal fibrosis could not be confirmed histologically, the tumor responded well to steroid therapy.

IgG4-related sclerosing mesenteritis in a 7-year-old Saudi girl.

Sclerosing mesenteritis (SM) is a rare, benign inflammatory disorder of unknown etiology, affecting the membranes of the digestive tract that involves lymphoplasmacytic inflammation, fat necrosis, and fibrosis of the mesentery. We report a child patient with a history of recurrent abdominal pain and fever who was found to have an intra-abdominal mass suspicious for malignancy. A tissue biopsy revealed the diagnosis of SM associated with IgG4-related systemic disease. The patient is currently maintained on 5 mg prednisone daily and no recurrence of symptoms was noted during the 24-month follow-up period. We emphasize, therefore, that SM can present clinical challenges and the presence of SM should cue clinicians to search for other coexisting autoimmune disorders that can have various outcomes.

[Sclerosing mesenteritis: can it be a IgG4 dysimmune disease?]. / La mesentérite sclérosante est-elle une maladie dysimmunitaire à IgG4 ?

AIMS: Mesenteric panniculitis (MP), sclerotic mesenteritis (SM) and mesenteric lipodystrophy (ML) are the three histopathological forms of a rare inflammatory mesenteric disease. The pathogenesis is unknown until now. Hypothesis of a dysimmune disorder is advocated. Our purpose was to find histological basis to assert this hypothesis. MATERIAL AND METHODS: All patients with a diagnosis of inflammatory mesenteric disease made in Beaujon hospital were selected. A histological study and a systematic immunostaining with IgG4, CD3 and CD8 antibodies were performed for each patient with paraffin block available. Dysimmune features were defined by: a plasma cells component >30 %, an eosinophilic polynuclears component >10 %, a rate TCD8/CD3 >30 % and IgG4+ plasma cells >30/high power field (x400). Cases were classified in 3 forms on the basis of the predominant component: MP (lymphoid/plasma cell infiltrate), SM (fibrosis), ML (fat necrosis). RESULTS: Thirteen patients (7 men, 6 women) were selected, with a mean age of 57 years (21-80 years); a paraffin block was available for 10 patients. The clinical and histological presentations were heterogeneous: a mesenteric mass was the most frequent mode of revelation (6/13 patients) and all histological forms were present (3 MP, 5 SM and 5 ML). Nine patients had surgical biopsy, 2 had a trephine biopsy and 2 a resection. Standard histological analysis showed numerous eosinophils (> or =10 %) and plasma cells (>30 %) in respectively 3 (23 %) and 6 (46 %) of the 13 cases. The immunohistochemistry (performed in 10 patients) showed numerous TCD8+ in 80 % of the cases and numerous IgG4+ plasma cells in only 31 % of the cases (4 cases) (IgG4+ >30/x400). CONCLUSIONS: Our results demonstrate that inflammatory mesenteric diseases are heterogeneous: high components of plasma cells, eosinophils and TCD8+ lymphocytes were found respectively in 46, 23 and 80 % of cases; eosinophils were observed exclusively in sclerotic forms. Only 31 % of cases encompass numerous IgG4+ plasma cells, suggesting a pathogenesis different than hyper-IgG4 diseases.

Mechanisms of disease: adipocytokines and visceral adipose tissue--emerging role in intestinal and mesenteric diseases.

Adipose tissue has long been regarded as a passive type of connective tissue that stores energy as triglycerides and releases energy as free fatty acids, however, this point of view has now changed. The wide variety of products expressed and secreted by adipose tissue, such as adiponectin, leptin, and resistin, mean that the total adipose tissue mass can be defined as a real endocrine organ. The anatomic, metabolic and biochemical characteristics of visceral adipose tissue make it interesting in the context of intestinal and mesenteric diseases. These characteristics include increased lipolysis, venous drainage via the portal vein and local glucocorticoid excess owing to the specific expression of 11-beta-hydroxysteroid-dehydrogenase type 1. In this review, the role of the visceral adipose tissue and its secretory products in intestinal and mesenteric diseases is systematically reviewed, with special focus on 'creeping fat' in Crohn's disease and mesenteric panniculitis.