A58-year-old white female presented with an eight-month history of progressive lower abdominal pain and bloating. She experienced intermittent constipation followed by a five-month period of persistent loose, watery diarrhea, a 35-pound weight loss, fatigue, anorexia, and avoidance of food.
Her past medical and surgical history were significant for hypertension, depression, appendectomy, laparoscopic ovarian cystectomy (of benign histology), and cholelithiasis. Her medication list consisted of pindolol and sertraline. Her physical exam was remarkable for abdominal distention, palpable mass, fluid wave, shifting dullness, and hypoactive bowel sounds. There was no tenderness or organomegaly. She had a mild microcytic anemia with no leukocytosis. Liver chemistries and electrolytes were normal. The erythrocyte sedimentation rate was 51. The initial CT scan of the abdomen is shown at right. TH
What is the most likely differential diagnosis?
- Pneumatosis intestinalis;
- Ovarian carcinoma or peritoneal carcinomatosis;
- Sclerosing mesenteritis;
- Spontaneous bacterial peritonitis; or
The answer is C: sclerosing mesenteritis (SM). The CT scan shows a bulky heterogeneous mesenteric mass measuring approximately 8.7 x 6 x 10 cm, with a focal, 2-cm calcification at the lateral margin. The mass began at the proximal superior mesenteric artery, extended inferiorly to the top of the pelvis, and encased the body of the pancreas, central mesenteric vessels and the confluence of the portal, splenic, and superior mesenteric veins (SMV). The SMV was poorly visualized and may have been compressed or occluded by the mass. Diffuse abdominal and pelvic ascites also were seen.
Results of a needle biopsy of the mesenteric mass showed fibrous tissue and a mixed population of B cells and T cells consistent with sclerosing mesenteritis, a fibroinflammatory reactive process.
Sclerosing or retractile mesenteritis is an uncommon, idiopathic, nonneoplastic, tumor-like lesion that thickens and shortens the mesentery.1 The condition consists of a pathophysiological spectrum of disease, the classification of which is based on the predominant histological finding on tissue biopsy. Cases in which the predominant findings are fatty degeneration and necrosis are known as the mesenteric lipodystrophy variant; those in which chronic inflammation predominates are known as the mesenteric panniculitis variant; and finally, the predominantly fibrotic form is known as the retractile mesenteritis or mesenteric fibrosis variant.