What is your approach to managing sclerosing mesenteritis (mesenteric panniculitis)?

I have seen and followed dozens of patients with this diagnosis. As noted above, it is important foremost to be sure of the diagnosis. Mesenteric panniculitis can be part of the IgG4 associated spectrum and so a biopsy is useful if it can be done safely. The other disease in the differential is carcinoid syndrome which has the same sunburst appearance on CT/MRI as does mesenteric panniculitis. The patients may not have carcinoid-type symptoms nor elevated blood levels of serotonin if the tumor has not yet metastasized to the liver so measuring 5HT levels is insufficient. An octreotide scan is often indicated to rule out carcinoid. I have not, in my experience, seen a case of carcinoid, but numbers are limited.

Regarding treatment, it depend...

I have seen only 2 patients with it, so my personal experience is quite limited. The patients are typically referred by gastroenterology. First, I would make sure you are not missing an underlying malignancy, or IgG4-associated disease. A biopsy would be highly desirable. The treatment we implemented was 6 weeks of high dose steroids, with a taper, followed by a second line agent, which can be azathioprine (Imuran), or mycophenolate mofetil (CellCept), or even MTX. I suppose rituximab (Rituxan or biosimilar) may be an option. Follow-up is largely depending on subsequent imaging to see if your therapy is actually making a difference.