Obstructive pancreatitis: unusual causes of chronic pancreatitis.

Fifty-eight consecutive surgical pancreatic resections for chronic pancreatitis were examined. Eight cases were identified with obstructive pancreatopathy; all underwent pancreato-duodenectomy. Histological examination revealed that obstruction in three cases was due to duodenal wall cysts, and in two patients it was associated with pancreas divisum (the accessory papilla was obstructed by a neuroendocrine tumour in one case and by ectopic pancreatic tissue in the other). One case each was due to obstruction of an anomalous duct by vegetable matter, to segmental pancreatitis, and to an intraductal carcinoma. Obstructive pancreatitis has many causes and diligent pre-operative assessment is required as surgical resection may be beneficial. Special efforts should be made to identify ductal anomalies, duodenal cysts, ectopic pancreatic tissue, and small ampullary tumours of exocrine and endocrine origin in order to define the aetiology of pancreatitis.