Sclerosing mesenteritis, also called mesenteric panniculitis, is a rare non-neoplastic disease that affects the small bowel mesentery with chronic fibrosing inflammation. Although a relatively benign condition, sclerosing mesenteritis can have a prolonged debilitating course with a fatal outcomeThere are few data on the natural history and therapeutic options for this condition. Tamoxifen in combination with prednisone is teh most common treatment, and most patients respond. I did not find any reports of the use of Rituxan.
Savvas Hiridis et al, Sclerosing mesenteritis affecting the small and the large intestine in a male patient with non-Hodgkin lymphoma: a case presentation and review of the literature
Journal of Medical Case Reports 2008, 2:388