Mesenteritis

Mesenteritis is a term for inflammation of the mesentery, the tissue that attaches the intestines to the posterior abdominal wall. It most often refers to mesenteric panniculitis, at one end of a spectrum that includes retractile mesenteritis and lipodystrophy (sclerosing mesenteritis).

Etiology is unknown; many cases are idiopathic, but associations with autoimmune processes exist. Some reports link it to IgG4-related disease, prior abdominal surgery or trauma, infection, or malignancy; no single cause is established.

Clinical presentation ranges from asymptomatic to abdominal pain, bloating, nausea, weight loss, or fever. Inflammation or fibrosis can cause bowel obstruction in rare cases.

Diagnosis relies on imaging. CT commonly shows increased mesenteric fat attenuation (misty mesentery), small soft tissue nodules, and a pseudocapsule. MRI is an alternative; PET-CT may show uptake. Blood tests are nonspecific. A biopsy may be used to exclude cancer when imaging is unclear.

Treatment depends on severity. Many cases are observed if asymptomatic. Symptomatic disease is often treated with corticosteroids; responses vary. Steroid-sparing agents such as azathioprine or methotrexate may be used, and tamoxifen or rituximab in selected settings. Surgery is reserved for obstruction or other complications and does not cure the underlying disease.

Prognosis is variable. The disease can wax and wane; many patients have stable symptoms, and long-term outcomes are generally favorable. Recurrence after treatment may occur.