Bile Duct Papillary Adenoma Degenerating Into Cholangiocarcinoma

Abstract

A 79 year old Caucasian female was incidentally discovered to have transaminitis on routine labs and underwent right upper quadrant ultrasound revealing a dilated bile duct. MR Abdomen revealed a solid mass in the proximal common hepatic duct. She was asymptomatic without jaundice, weight loss, pruritus or abdominal pain. Additional and repeat labs showed a mildly elevated carbohydrate antigen 19-9 (CA-19-9) at 41.49 and normal carcinoembryonic antigen (CEA). Endoscopic Ultrasound (EUS) revealed a 1.5 x 2 cm mass in the common hepatic duct and fine needle aspiration showed atypical glandular papillary cells with no evidence of neoplasm. Endoscopic Retrograde Cholangiopancreatography (ERCP) with cholangioscopy demonstrated a frond-like mass in the common hepatic duct with pathology indicative of dysplastic epithelium consistent with low-grade dysplasia without frank malignancy. Repeat CA-19-9 level normalized at 30.11. She underwent pre-operative evaluation and was found to have severe aortic stenosis necessitating valve replacement and thus biliary surgery was delayed. Repeat labs four months later showed highly elevated CA-19-9 at 1382.10 concerning for degeneration of adenoma to malignancy. She underwent diagnostic laparoscopy with resection of the extrahepatic biliary tree including bifurcation, Roux-en-Y hepaticojejunostomy, hilar lymphadenectomy and cholecystectomy. Hepatic duct mass pathology showed a 3 x 1.4 cm exophytic papillary adenoma with high grade dysplasia, within which was a 0.3 cm moderately differentiated adenocarcinoma involving the left proximal hepatic duct invading into but not through the hepatic duct wall with negative margins. Final diagnosis was Stage I cholangiocarcinoma (T1N0M0) within a papillary bile duct adenoma. Bile duct adenomas (BDA) are rare bile duct tumors accounting for roughly 6% of extrahepatic tumors. Adenomas of the extrahepatic bile ducts may present with obstructive symptoms or may be asymptomatic, found incidentally on physical exam or imaging. Though defined as a benign tumor, BDAs have carcinogenic potential. The incidence and timing of malignant transformation is not well defined and thus prompt surgical resection is indicated for treatment. In our case, after a necessary delay in therapy, CA-19-9 levels dramatically increased and her tumor that was initially felt to be BDA degenerated to cholangiocarcinoma.Figure 1Figure 2Figure 3