Abdominal ultrasonogram of autoimmune pancreatitis: Five cases of pancreatic lesions accompanied by Sjögren syndrome.

Abstract

The concept of autoimmune pancreatitis has recently been established, and ultrasonographic findings we obtained from five cases consistent with autoimmune pancreatitis are reported here. Case 1, a 77-year-old man, was admitted complaining of loss of body weight. Serum hepatobiliary enzymes and γ-globulin levels were elevated, and antinuclear antibody was positive, Abdominal ultrasonography showed dilatation of the intrahepatic bile duct, wall thickening of the common bile duct and hypoechoic swelling of the pancreatic head and body. ERCP revealed multiple stenosis of the intra-and extra-hepatic bile ducts, and diffuse irregular narrowing of the main pancreatic duct. The patient complained of thirst, and the minor salivary gland was examined histologically. Our diagnosis was Sjögren syndrome accompanied by sclerosing cholangitis and a pancreatic lesion. Obstructive jaundice also developed, and PTCD was therefore performed. Both the pancreatic swelling and multiple stenosis of the bile duct improved after steroids were administered. Case 2, a 71-year-old man, was admitted with jaundice. Abdominal ultrasonography showed hypoechoic swelling of the pancreas. ERCP showed stenosis of the common bile duct in the pancreatic head region and diffuse irregular narrowing of the main pancreatic duct. Histological examination of the minor salivary gland suggested Sjögren syndrome. Steroids were therefore administered because the presence of both hyper-γ-globulinemia and positive antinuclear antibody suggested involvement of the autoimmune mechanism. Steroid therapy improved the jaundice as well as the findings from the cholangiograms and pancreatograms. We also encountered three similar cases, all consistent with the concept of autoimmune pancreatitis. The ultrasonographic findings of the pancreatic lesion (1) showed them as homogeneous and markedly hypoechoic areas and, (2) visualized the main pancreatic duct in the lesion, which facilitated a differential diagnosis of the neoplastic lesions. (3) Steroid therapy effectively decreased the hypoechoic area; in some cases, however, a hypoechoic area remained around the main pancreatic duct.