S3271 Mega Gallbladder: A Markedly Distended Gallbladder in a Young Patient With Primary Sclerosing Cholangitis

Introduction: A giant gallbladder (GGB) is a rare condition defined by: length >14 cm, a volume >1.5 L, or a weight >1.5 kg. It is usually associated with obstructive stones, chronic cholecystitis, neoplasms, adhesions, bacterial infections of the gallbladder, and functional gallbladder disorders. Herein we describe a case of a young patient with a 18.5 × 6.27 × 4.39 cm gallbladder in the setting of a type IVa choledochal cyst (CC4A) and primary sclerosing cholangitis (PSC). Case Description/Methods: A 19-year-old man with a past medical history of primary sclerosing cholangitis (PSC) presented to the ED for evaluation of 3 weeks of jaundice, scleral icterus and darkening of his urine. Computed tomography imaging showed severe intrahepatic biliary ductal dilatation, severe common bile duct (CBD) dilatation (2.2 cm), and a severely distended gallbladder with debris/stones in the distal CBD. A endoscopic retrograde cholangiopancreatography (ERCP) showed diffusely dilated and irregular intrahepatic ducts concerning for PSC with cytology brushings of the CBD showing atypical cells. A stent was placed within the CBD to decompress the biliary tree, improving the intrahepatic bile flow. However, the total bilirubin remained markedly elevated throughout the course of the patient’s stay eventually requiring an exploratory laparotomy with cholecystectomy, hepaticojejunostomy, and resection of the bile duct and choledochal type IV cyst. The gallbladder was severely enlarged, measuring 18.5 × 6.27 × 4.39 cm, and extending down into the pelvis. A liver biopsy revealed rebridging fibrosis with a chronic biliary/cholestatic pattern of injury. The possibility of eventually requiring a liver transplant was discussed with the patient and he was discharged. Discussion: Although gallbladder abnormalities are a common complication of PSC, GGB is quite rare with only a handful of documented cases published. In our case, an exploratory laparotomy would later reveal a CC4A. We believe the chronic inflammation and fibrosis from PSC caused an ampullary stenosis and biliary ectasia. The stenosis in conjunction with the choledochal cyst created a chronic back-flow, cholestasis, and chronic biliary pressure resulting in marked gallbladder distention. Additionally, this patient’s pathology revealed chronic cholecystitis which may have contributed to prolonged biliary retention, resulting in a giant gallbladder.