Background : Gallbladder duplication is a rare congenital anomaly seen in 1 of 3000 to 4000 births. Diagnosis can be made pre-operatively through imaging, however, many are diagnosed incidentally during gallbladder surgery for cholelithiasis. Immediate detection of gallbladder duplication is important to avoid perioperative complications since other congenital vascular and biliary duct anomalies may be present.

Methods : This is a case of a 40-year-old female who presented with chronic calculous cholecystitis. She had intermittent bouts of right upper quadrant pain, radiating to the back, for one year. Persistence and increased severity of pain prompted consult at the emergency department. Whole abdominal ultrasound revealed at least three lithiases within the gallbladder measuring up to 1.5cm. She underwent laparoscopic cholecystectomy with cholangiography. It was discovered intraoperatively that she had a duplicate gallbladder.

Results : There were no intraoperative or postoperative complications, and the patient was eventually discharged. Histopathology of the gallbladder showed chronic cholecystitis, and was consistent with gallbladder duplication.

Conclusions : In patients suspected to have a congenital anomaly of the gallbladder, such as duplication, preoperative investigation with ultrasound or MRCP to establish the diagnosis is important. In cases where the anomaly is detected intraoperatively, a cholangiography may be done to establish the anatomy of the biliary tree. Immediate recognition of the anomaly may prevent unwanted injuries and complications.