Adenomyomatosis of the Gallbladder With Pancreaticobiliary Maljunction in a Child

Abstract

An 8-year-old girl referred for recurrent abdominal pain for 1 year had a normal physical examination except mild tenderness in the right hypochondrium and normal laboratory values such as AST/ALT 23/12 U/L, GGT 15 U/L, total bilirubin 0.9 mg/dL, and lipase 11 U/L. Magnetic resonance cholangiopancreatography (MRCP) showed thickening of the gallbladder wall, multiple heterogeneous hyperintense cysts of the gallbladder fundus, and no dilatation of the bile duct (Fig. 1). Endoscopic retrograde cholangiopancreatography showed pancreaticobiliary maljunction (PBM) not previously seen on MRCP (Fig. 2). The length of the common channel was approximately 1 cm outside duodenal wall (Fig. 2). She was diagnosed with adenomyomatosis of the gallbladder (AMG) accompanied by PBM and underwent total resection of the extrahepatic bile duct and Roux-en-Y hepaticojejunostomy. Histopathology showed typical AMG findings and no malignancy. She remained free of abdominal pain at 5 months after surgery.FIGURE 1: Magnetic resonance cholangiopancreatography (T2-weighted coronal image) showed thickening of the wall of the gallbladder fundus and multiple heterogeneous hyperintense cysts in the gallbladder fundus. Arrows, gallbladder fundus.FIGURE 2: Endoscopic retrograde cholangiopancreatography showed the pancreaticobiliary maljunction. Arrowhead, common bile duct; arrow, pancreatic duct; ∗, common channel; ruler, 1 cm in scale.AMG is relatively common in adults (1), but we know of only 4 previously reported pediatric cases (2). Once the diagnosis of PBM is established, immediate prophylactic surgery is recommended irrespective of biliary dilatation because biliary cancers are frequent in adults with PBM (3). AMG with PBM has been reported previously in adults (4) but not in children. Tanno et al (4) reported that chronic inflammation and/or increased intraluminal pressure caused by regurgitation of pancreatic juice into the gallbladder may lead to AMG in patients with PBM. MRCP and/or endoscopic retrograde cholangiopancreatography should be performed to ensure prompt diagnosis of PBM.