The presence of some degree of fibrosis, chronic inflammation, and fat necrosis in all three lesions, as well as their common demographic and clinical characteristics, suggest that the three diagnostic groups represent a single clinical entity.2 Sclerosing mesenteritis is used as an umbrella term that encompasses all three histologic variants.
Numerous theories exist to explain the pathogenesis of the condition, most commonly relating to a non-specific reaction to mesenteric injuries such as antecedent surgery or abdominal trauma, or possibly autoimmunity, ischemia/infection, and or paraneoplastic phenomena.
A study of 68 cases of mesenteric panniculitis undertaken by Durst, et al., showed that the age range is diverse, affecting patients from seven to 82 years.3 In another study, Emory, et al., reported an average age of 60.1 years at presentation.2 In both studies there was a slight male preponderance, with a male: female ratio of 1.9:1, and 1.8:1.2,3
In the largest reported experience with patients with sclerosing mesenteritis from a single institution, the majority were male (72%) with an age range of 34-87 years.10,11 Of these patients, the most common presenting complaints are abdominal pain (36%-67%), vomiting (18%-32%), palpable abdominal mass (16%), anorexia (7%-17%), weight loss (14%-45%), constipation (8%-15%), diarrhea (7%-26%), and rectal bleeding (5%). The duration of symptoms varies from 24 hours to two years.3-10 In most cases, the blood chemistry and urinalysis were reported to be normal, although an elevated sedimentation rate has been reported in a minority.3,11
Diagnosis usually depends on imaging studies (most often CT scan) and pathological review of biopsy specimens. Concurrent pathology is found in 18%-25% of cases, including lymphoma (7%), cholelithiasis (4%), cirrhosis of the liver (3%), and abdominal aortic aneurysm (3%).3,10 Other conditions associated with idiopathic fibrosis, such as retroperitoneal fibrosis and sclerosing pancreatitis, have been reported to occur together with SM.4,10
To date, treatment options are guided by anecdotal experience and reports of open label clinical results.10,11 Clinical and experimental studies have suggested a possible hormonal influence on fibrous proliferation in retroperitoneal fibrosis, which led to the discovery of the beneficial effect of anti-estrogenic treatment with tamoxifen.5,6 Clark, et al., had noticed that tamoxifen was successfully used in the treatment of desmoid tumors and then reported its use in two cases of retroperitoneal fibrosis.5 Others have since used tamoxifen in sclerosing mesenteritis, including a relatively large experience from our institution that suggests the combination of tamoxifen with a prednisone taper may be the most beneficial treatment for this condition.7,10,11
Other treatments that have been reported to be of some benefit include combination of corticosteroids and colchicine or azathioprine, although these reports include very small numbers of patients.8,10 Ginsburg, et al., reported their experience with thalidomide in a short term, open-label study in five symptomatic subjects.12 Four patients (80%) experienced an improvement in symptoms, and one achieved complete remission by week four, which was sustained. There was also a decrease in inflammatory markers, although no changes were noted on follow-up CT scans.
The natural history of sclerosing mesenteritis is quite variable, with a few patients undergoing spontaneous remission, many experiencing an indolent course, and others progressing to bowel obstruction or other complications, including chylous ascites, mesenteric venous or arterial occlusion, and malnutrition (often resulting in the need for parenteral nutrition).10,11 There have been fatal cases of this condition reported in the literature; however, Durst, et al., found that of 40 patients undergoing exploratory laparotomy and biopsy, only one patient died as a direct result of the disease after 12 years and several explorations.9-11 In the remaining 39 patients, their symptoms resolved without any further treatment, although in some the abdominal mass was persistently palpable.3. Similarly Emory, et al., found that after following 42 patients for an average of 9.5 years, only three patients had complications that resulted in death, all of which occurred in the postoperative period.2