Duplicate gallbladder masquerading as a choledochal cyst: a case of single-port robotic surgery.

Gallbladder duplication is a rare congenital anomaly (1 in 4000 births) that can mimic other biliary pathologies, risking iatrogenic injury. A 61-year-old male presented with fever, right upper quadrant pain, and elevated aminotransferases. Contrast-enhanced computed tomography and magnetic resonance imaging initially suggested a 3.6-cm Todani type II choledochal cyst posterior to the gallbladder. Suspecting duplication, surgeons utilized a single-port robotic approach via the da Vinci SP system. Intraoperatively, two distinct gallbladders with independent cystic ducts were identified and successfully resected without complications. The operative time was 65 min, and histopathology confirmed chronic cholecystitis in both specimens. This case highlights the difficulty of differentiating gallbladder duplication from a type II choledochal cyst using cross-sectional imaging. Single-port robotic cholecystectomy offers enhanced visualization and articulating instrumentation, facilitating the safe, precise management of complex biliary anomalies.