A case of double gallbladder with cholelithiasis diagnosed with transabdominal ultrasound.

Gallbladder duplication is a rare biliary tract malformation. According to Boyden's classification, the double gallbladder is divided into the bilobed gallbladder and truly duplicated gallbladder, including the Y-shaped [cystic ducts uniting before entering the common bile duct (CBD)] and H-shaped (cystic ducts separately entering into the CBD) types. The case described here was the Boyden H-shaped type. Preoperative diagnosis of the disease is essential to rationalize surgical planning and avoid complications. Transabdominal ultrasound is the first imaging technique that can diagnose biliary tract abnormality at many institutions. The popularization of typical ultrasound images of the double gallbladder could aid in surgical planning and avoiding complications.