Gallbladder duplication masquerading as a dilated common bile duct with choledocholithiasis.

A duplicate gall bladder was diagnosed at laparoscopy, having been erroneously diagnosed on ultrasonography as a dilated common bile duct with choledocholithiasis. Gallbladder duplication is a congenital abnormality with a rare incidence, occuring in approximately 1 in 4 000 births and 0.020% in al large autopsy series. This report highlights its existence to improve awareness and lessen the potential for biliary injury.