Pancreatitis-associated Sclerosing Mesenteritis: A Rare Presentation

Abstract

Sclerosing mesenteritis, first described by Jura in 1924 as retractable mesenteritis, rarely involves the pancreas. Pancreatic involvement typically mimics a neoplastic process. We present what we believe to be the first reported case of pancreatitis-associated sclerosing mesenteritis. A 53-year-old African American female presented with abdominal pain associated with nausea, vomiting, and distention. Physical exam revealed epigastric tenderness and decreased bowel sounds. Lipase on admission was 542 U/L. CT showed pancreatic fat-stranding with reactive lymphadenopathy. A diagnosis of acute pancreatitis of unknown etiology was made and the patient was medically managed. The postdischarge course was complicated by persistent abdominal pain with features suggestive of biliary pancreatitis. Laparoscopic cholecystectomy and biliary diversion for a distal CBD stricture were then performed. Post-discharge, she had recurrent abdominal pain and weight loss over a two-month period. Repeat CT showed a worsening inflammatory mass of the pancreatic head/body, atrophy of the tail, with progressive porta hepatis and mesenteric lymphadenopathy. These findings were concerning for a neoplasm. However, EUS core biopsy and serum tumor markers remained negative for malignancy. Thus, clinical suspicion for an autoimmune process was established. She was treated conservatively and three months later, a follow-up MRI showed significant interval enlargement of an infiltrating mesenteric mass tracking along the root extending inferiorly from the pancreatic head/neck which was highly-suggestive of sclerosing mesenteritis. The patient was treated with two months of prednisone with significant improvement in symptoms. Post-steroid MRI showed over 50% reduction in the size of the mass-like area. Sclerosing mesenteritis is often referred to as a great masquerader as it typically has clinical and radiographic features of malignancy. The etiology of sclerosing mesenteritis remains unclear. We hypothesize that our patient's acute pancreatitis may have precipitated the development of sclerosing mesenteritis. Pancreatic involvement in sclerosing mesenteritis is rare. The differential diagnosis is wide and biopsies to exclude malignancy are essential. There is no established treatment for sclerosing mesenteritis. Medical therapy can include glucocorticoids, hormonal therapy and immunomodulators. Our patient responded well to prednisone, but long-term response is yet to be established.