The preoperative workup gave no hint. A 32-year-old woman with recurring pain in her upper right abdomen had an abdominal ultrasound showing a gallbladder of normal size and wall thickness, a normal caliber cystic duct and common bile duct, and multiple stones measuring roughly 0.5 to 1.5 centimeters. Her blood counts, liver function tests, and coagulation profile were all normal. She was scheduled for an elective laparoscopic gallbladder removal.
Inside, surgeons found the organ divided lengthwise by a septum into two separate cavities, each draining through its own independent cystic duct into the common bile duct.
