Abstract
A 21-year-old man was diagnosed with segmental adenomyomatosis of the gallbladder based on ultrasonography and computed tomography images. Computed tomography with drip infusion cholangiography revealed that the cystic duct joined the infraportal type of the left lateral bile duct (IPLLBD), which runs caudal to the umbilical portion, and that the left medial bile duct joined the right hepatic duct without forming the left hepatic duct. We planned a single-incision laparoscopic cholecystectomy with fluorescent cholangiography. The fluorescent cholangiography visualized the anatomic variant of the biliary system, and the cystic duct was divided safely. Fluorescent cholangiography is a suitable procedure to depict complex biliary anatomic variations in this patient. IPLLBD without the formation of the left hepatic duct is potentially hazardous during cholecystectomy.