Silent pancreatic pseudocyst. An unusual cause of extrahepatic biliary obstruction.

Extrahepatic biliary obstruction due to mechanical obstruction of the common bile duct is a relatively rare complication of pancreatic pseudocyst. When jaundice does occur, clinical or laboratory evidence of associated primary hepatobiliary disease or acute pancreatitis has invariably been present. The patient described had a 3-month history of painless juandice, 40-lb weight loss, pruritus, and hepatomegaly, but no clinical or biochemical evidence of acute or chronic pancreatitis. After initial evaluation, including an abdominal echogram and a transhepatic cholangiogram, carcinoma of the head of the pancreas was diagnosed preoperatively. At laparotomy, a small pancreatic pseudocyst obstructed the terminal portion of the common bile duct. This case illustrates that a pancreatic pseudocyst should be considered in the differential diagnosis of obstructive jaundice, even in the absence of clinical evidence of pancreatitis or pseudocyst formation.