Carcinoma of the pancreas presenting as acute pancreatitis: CT diagnosis.

Three cases are reported in which acute pancreatitis was the presenting manifestation of an underlying carcinoma of the head of the pancreas. The rare association of acute pancreatitis and pancreatic carcinoma is reviewed and possible pathogenetic mechanisms are discussed. An underlying neoplasm should be suspected in a middle-aged or elderly patient presenting for the first time with acute pancreatitis for which no other cause is found. CT may suggest the correct diagnosis by identifying focal rather than diffuse pancreatic involvement, pancreatic duct dilatation, or lymphadenopathy.