Pancreatitis associated with neuroendocrine (islet cell) tumors of the pancreas

Background The association of pancreatitis with neuroendocrine tumors of the pancreas is uncommon, whereas its association with exocrine pancreatic cancer is well recognized. Since the latter, but not the islet cell tumor, is thought to originate within the ductal system, it is not surprising that pancreatitis is less likely to result from the islet cell tumor. The senior author has recently noted that the first recognizable indication of an islet cell carcinoma may be one or more discrete attacks of acute pancreatitis. Methods and results Acute pancreatitis, resulting from an islet cell tumor, has been observed in five patients, in one of whom it had become chronic. In four of the patients, the tumor was malignant. A review of the English language literature reveals 14 such patients with pancreatitis, and 2 others have been noted in other languages (a total of 21 patients). The tumor was malignant in 15 of the 21 patients (71%). Although the development of pancreatitis was found to result from the obstruction of the duct in most patients, at least three seemed unrelated. In 12 of 21 cases (57%), an acute attack of pancreatitis, usually recurrent, was the initial syndrome, in contradistinction to pancreatitis resulting from exocrine tumors, which has usually been chronic in nature. Conclusion Pancreatitis, particularly acute pancreatitis, may result from an islet cell tumor. Although unusual, its occurrence may be the first signal of the presence of the tumor. In our experience, obstruction of the pancreatic duct by the islet cell carcinoma appears to be the important etiologic factor.