Definitive diagnosis of a duplicate gallbladder can only be made intraoperatively: report of a case.

Duplicated gallbladders are rare congenital anomalies that are important in clinical practice as they may cause clinical, surgical, and diagnostic problems. Here, we describe the case of a 79-year-old female patient who presented with acute cholangitis. Abdominal ultrasonography, endoscopic ultrasonography, computed tomography, and magnetic resonance imaging revealed an intrahepatic cystic lesion, suggesting communication with the intrahepatic bile duct; no evidence of a polypoid lesion within the cystic lesion was observed. Based on these findings, intrahepatic cholangiectasis, intrahepatic bile duct cystadenoma, and the presence of a duplicated gallbladder were suspected, and surgery was performed. During surgery, a tube inserted into the common bile duct from a cystic duct facilitated intraoperative cholangiography, which indicated the presence of a duplicated gallbladder. Thus, we believe that a duplicated gallbladder should be an additional consideration when typical gallbladder disease symptoms are present under certain circumstances. A multimodal imaging approach can help to establish the diagnosis preoperatively or intraoperatively.