Small Bowel Obstruction as a Rare Complication of Progressive Sclerosing Mesenteritis

Introduction/Objective Sclerosing Mesenteritis is an uncommon, idiopathic, localized inflammatory syndrome involving the small intestine and colonic mesentery. It is considered a benign condition that commonly occurs in elderly with a gender predilection for males, and its etiology remains unknown. Small Bowel Obstruction (SBO) is a rare, unexpected, but detrimental complication of progressive Sclerosing Mesenteritis. Herein, we present a case of an enlarging, progressive Sclerosing Mesenteritis with extensive involvement of the small bowel and mesentery requiring two consecutive major surgical interventions. Methods/Case Report A 72-year-old male with Myelodysplastic Syndrome (MDS) and recent history of loop ileostomy due to distal intestinal obstruction secondary to enlarging Sclerosing Mesenteritis, presented to our institution with non-specific symptoms of worsening abdominal pain and multiple episodes of gastrointestinal bleeding. Radiographic investigation revealed SBO and he subsequently underwent exploratory laparotomy resulting in total enterectomy with excision of mesenteric mass, extended right colectomy, Whipple procedure, and gastrostomy. The specimens were sent to pathology for histopathological evaluation and gross examination revealed several bosselated, tan-white, firm and rubbery, fibrotic lesions with associated lobulated fibroadipose tissue. Microscopic examination showed extensive mesenteric fibrosis with dense bundles of collagen fibers, areas of fat necrosis, mucosal ischemia and calcification involving the small bowel and serosal surface of large intestine and peritoneum. The lesional cells showed minimal atypia, mitoses, and lacked the Beta-catenin nuclear staining seen in mesenteric fibromatosis. Given the clinical history and histopathological findings of the lesion, we favored the diagnosis of Sclerosing Mesenteritis. Results (if a Case Study enter NA) N/A Conclusion The etiology of Sclerosing Mesenteritis is not well-understood and there are cases of Sclerosing Mesenteritis reported in the literature in association with trauma, surgery, malignancy, and IgG4-related disease. Our patient’s post-operative history was complicated by short gut syndrome, and he is currently requiring small bowel transplant. We report this case for its unusual and aggressive clinical presentation, and to heighten clinical awareness for detrimental consequences of this seemingly benign condition.