AN ATYPICAL CASE OF A CHOLEDOCHOCOELE

C Turbide, I Yusofff, J Parent

Div of Gastroenterology, McGill University Health Center, Montreal, Quebec

BACKGROUND: Chledochocoele is a rare entity usually diagnosed by typical cholangiographic appearance but this image may not always be specific.
CASE: A 49 yo female presented with a 2-week history of painless jaundice, weight loss and prurituuis. The abdomen was normal on exam. Liver function tests demonstrated arevealed a cholestaticpattern pattern (bili 333, ALP 838). Abdominal ultrasound showed significant intrahepatic and extrahepatic bile duct dilation without a clear cause. The common bile duct (CBD) measured 18mm. Abdominal CT scan confirmed the intra and extrahepatic biliary dilatation again without any evidence of an obstructing mass. No pancreatic duct dilatation was seen. An MRCP showed protrusion and herniation of the distal CBD into the papilla thought to be likely secondary to a choledochocele. There was Nono evidence of periampullary lesion was identifiedtumor. ERCP revealed a smooth papilla that was grossly enlargedsmooth, along with marked fusiform dilatation of the distal CBD. A biliary sphincterotomy was performed and the patient's jaundice fully resolved rapidly as did the biliary dilatation (on ultra-sound). An endoscopic ultrasound (EUS) demonstrated mucosal thickening of the ampulla of (10 mm)in thickness in keeping The image was compatible with an ampullary tumor. Initial The biopsies demonstrated chronic active inflammatory changes associated with epithelial hyperplasia and repeat biopsies suggested a possible adenoma on a single one sample. The patient was sent to the OR and the final pathology was an in situ and infiltrating moderately differentiated ampullary adenocarcinomaarising in the periampullary duodenal mucosa.
DISCUSSION: The choledochocoele is a type III choledochal cyst. Its etiology is unknown. Adult patients with choledochal cysts usually present with epigastric pain, pancreatitis or cholangitis. The diagnosis is made by cholangiogram. The differential diagnosis includes intraluminal duodenal diverticulum and duodenal duplication cyst. The risk of malignant transformation is less common than for the other types of cysts and therefore endoscopic therapy has been suggested as a first step in the management of most symptomatic patients with choledochocoeles. Our patient, despite a typical cholangiogram, had 1 set of biopsies suspicious for an adenoma with an EUS showing a mass. Therefore, the initial diagnosis was challenged.
CONCLUSION: This case highlights the difficulty of accurate diagnosis of ampullary lesions on both imaging and histopathalogyically and emphasizes the importance multiple imaging modalities in achieving an accurate diagnosis.