Eosinophilic pancreatitis mimicking pancreatic neoplasia.

Eosinophilic pancreatitis (EP) is a rare disease. It typically occurs in the setting of either eosinophilic gastroenteritis or the hypereosinophilic syndrome. Isolated eosinophilic infiltration of the pancreas is less common. EP usually presents as a pancreatic tumour with abdominal pain and/or obstructive jaundice. The diagnosis is often not made until after pancreatic resection under suspicion of a pancreatic tumour. The case of a 14-year-old boy whose initial presentation was suggestive of a pancreatic tumour is reported. Radiological evaluation revealed a pancreatic mass suggestive of a pancreatic tumour obstructing the duodenum and common bile duct. The patient underwent surgery and a gastrojejunal anostomosis, tube cholecystostomy and biopsy were performed with no postoperative complications. The diagnosis of EP was established after surgical biopsy. The biopsy specimen revealed prominent eosinophilic infiltration. Serum immunoglobulin E levels were elevated. The patient was treated with oral prednisolone (40 mg/day). After two months of oral steroid therapy, clinical manifestations rapidly improved and peripheral eosinophilia subsided. Computed tomography scan revealed remission of the pancreatic mass-like lesion.