Sclerosing Mesenteritis, a Rare Cause of Mesenteric Mass in a Young Adult: A Case Report.

Sclerosing mesenteritis (SM) is a rare fibroinflammatory disorder that involves mesenteric adipose tissue, more frequently localized in the small intestine, with an insidious clinical presentation having symptoms related to mass effect, usually resulting in bowel obstruction, mesenteric ischemia, as well as rapid weight loss. We report a case of a 23-year-old male presenting with palpable abdominal mass, mesogastric pain, and a history of rapid weight loss, who underwent exploratory laparoscopy. A hemorrhagic and gelatinous nodular tumor mass of the mesentery was identified and the surgical procedure was converted to a laparotomic approach. Histologically, the mass was composed of a proliferation of bland-looking spindle cells with slightly eosinophilic cytoplasm and elongated normochromatic nuclei with mild nuclear atypia, haphazardly set in a collagenized stroma; fat necrosis and inflammatory cells (lymphocytes, plasma-cells, and histiocytes) were also evident. The diagnosis of sclerosing mesenteritis was made. Our case emphasizes that histology remains pre-eminent for a correct diagnosis of SM, as pre-operative radiological-based diagnosis is non-specific.