Primary mesenteritis, mesenteric fibrosis and mesenteric fibromatosis. Report of four cases, pathology, and classification.

Primary mesenteritis is a rare disease. Two cases and two additional patients with mesenteric fibrosis/fibromatosis are reported. A classification of primary and secondary mesenteritis is suggested in order to replace the confusing variety of terms used for the same disease process. Differential diagnosis of mesenteric fibrosis versus mesenteric fibromatosis may be difficult, and some criteria for the separation of these two entities are discussed. Among the clinical symptoms, transmission of aortic pulsations to the anterior abdominal wall is a rare but important aid for diagnosis. Associated diseases are malignant lymphoma, colonic adenomatosis (Gardner's syndrome) and retroperitoneal fibrosis. Microscopically, mesenteric lipomatosis and Whipple's disease must be ruled out. Usually, surgical treatment is not necessary. Prednisone and azathioprine may be helpful in severe cases. Fatal outcome of primary mesenteritis is extremely rare.