Giant Calculus with More than 100 Small Calculi in Choledochal Cysts.

Giant biliary calculus in the common bile duct (CBD) is rare. Giant calculus of choledochal cyst (CC) is even rarer, and no case of giant calculus of CC with more than 100 calculi has been reported in the indexed literature. We present the case of a 8.0 × 4.5 × 4.0 cm sized giant calculus with >100 small calculi in type IVa CCs with heterotopic pancreas in a 45-year-old male, which is a surprisingly rare occurrence. Magnetic resonance cholangiopancreatography showed multifocal irregular dilatation of intrahepatic biliary radicles with multiple filling defects with a giant calculus in CC with cholelithiasis. The case was successfully managed with open cholecystectomy and choledochotomy with retrieval of 1 giant and more than 100 small calculi with excision of CC with Roux-en-Y hepaticojejunostomy. Histopathological examination (HPE) showed inflamed CC identified with focal areas of surface ulceration with increased fibrosis areas in the wall and few pancreatic acini. A bile duct calculus is defined as "giant" when the size is 5 cm or more. Stone formation within is the most frequent complication of CC. Most intracystic calculi have been described as soft, earthy, and pigmented in appearance, supporting bile stasis as a primary etiologic factor. The only treatment for giant calculus of CBD or CC is surgical. Endoscopic treatment is mostly unsuccessful and open surgery is the treatment of choice due to giant size, increased load of calculus, and presence of calculi in the left and right hepatic ducts.