Adenocarcinoma of the Extrahepatic Bile Ducts



Adenocarcinoma of the Extrahepatic Bile Ducts


Hanlin L. Wang, MD, PhD





Key Facts


Terminology



  • Malignant neoplasm arising from epithelium lining right and left hepatic ducts, common hepatic duct, and common bile duct



    • Perihilar bile duct carcinoma


    • Distal bile duct carcinoma


Etiology/Pathogenesis



  • Developmental anomalies


  • Primary sclerosing cholangitis


Clinical Issues



  • Poor prognosis with 10% overall 5-year survival


  • Surgical resection is only hope for long-term survival


  • Prognostic indicators include tumor stage, location, histology, and surgical margins


Image Findings



  • Biliary stricture, wall thickening, intraluminal mass


Microscopic Pathology



  • Wide spectrum of histologic appearance ranging from glandular structures to solid or cord-like clusters to individual tumor cells


  • Malignant glands are arranged in haphazard pattern, infiltrating duct wall


  • Often associated with desmoplastic stroma


  • Nuclear pleomorphism with increased N:C ratio, nuclear grooves, and brisk mitotic activity


Top Differential Diagnoses



  • Reactive periductal glands


  • Indistinguishable from pancreatic ductal carcinoma histologically and immunophenotypically






Segmental resection for períhilar bile duct carcinoma shows marked thickening of the common hepatic duct with firm, white cut surfaces image. A portion of dilated cystic duct is present image.






Cross section of a Whipple specimen shows distal bile duct carcinoma involving the intrapancreatic portion of the common bile duct and causing marked thickening of the duct wall image.


TERMINOLOGY


Synonyms



  • Extrahepatic cholangiocarcinoma


Definitions



  • Malignant neoplasm arising from epithelium lining right and left hepatic ducts, common hepatic duct, and common bile duct


  • Perihilar bile duct carcinoma



    • Arises in extrahepatic bile ducts upstream to origin of cystic duct



      • Klatskin tumor occurs at confluence of right and left hepatic ducts


    • Comprises 70-80% of extrahepatic cholangiocarcinoma


  • Distal bile duct carcinoma



    • Arises in common bile duct (including intrapancreatic portion) above ampulla of Vater


    • Comprises 20-30% of extrahepatic cholangiocarcinoma


  • Diffuse involvement of extrahepatic bile ducts is rare, comprising ˜ 2% of extrahepatic cholangiocarcinoma


ETIOLOGY/PATHOGENESIS


Developmental Anomaly



  • Choledochal cyst


  • Abnormal choledochopancreatic junction


Chronic Inflammation



  • Primary sclerosing cholangitis


  • Cholelithiasis (controversial)


Parasitic Infection (Flukes)



  • Clonorchis sinensis


  • Opisthorchis viverrini


Genetic Syndromes



  • Familial adenomatous polyposis


Molecular Alterations



  • KRAS mutations in ˜ 30% of cases


  • Overexpression of p53 oncoprotein in ˜ 50% of cases


CLINICAL ISSUES


Epidemiology



  • Incidence



    • 0.53-2 per 100,000 in population


  • Age



    • Primarily seen during 6th and 7th decades of life


  • Gender



    • Slight male predominance


Presentation



  • Nonspecific symptoms and signs



    • Abdominal pain, malaise, anorexia, nausea, vomiting, weight loss


  • Symptoms and signs of biliary obstruction



    • Jaundice, pruritus, acholic stools, dark urine


Laboratory Tests



  • Elevated serum CA19-9, CEA, and CA125 levels


Treatment



  • Surgical resection



    • Only hope for long-term survival


    • Segmental resection



      • May include partial hepatectomy for perihilar bile duct carcinoma


    • Whipple procedure for distal bile duct carcinoma


  • Combined modality therapy, including chemotherapy and radiotherapy


Prognosis



  • 10% overall 5-year survival


  • Prognostic indicators



    • Tumor stage



      • Most important prognostic indicator


    • Tumor location




      • Better prognosis for distal bile duct carcinoma due to early detection and resectability


    • Histologic grade



      • Poorly differentiated tumors are associated with worse prognosis


    • Histologic variants



      • Poorer prognosis for signet ring cell carcinoma


      • More favorable outcome for papillary adenocarcinoma


    • Surgical resection margins



      • Improved overall survival for those with negative resection margins


    • Lymphovascular invasion



      • Associated with adverse outcome


    • Perineural invasion



      • Associated with adverse outcome


IMAGE FINDINGS


Ultrasonographic Findings



  • Duct dilation indicative of downstream obstruction


CT and MR Findings



  • Infiltrative pattern



    • Duct wall thickening, obliteration of duct lumen


  • Mass-like lesion



    • Distension of duct by intraluminal mass


Cholangiographic (ERCP) Findings



  • Bile duct stricture


MACROSCOPIC FEATURES


General Features



  • Firm, white, and gritty cut surface


  • 4 categories traditionally



    • Polypoid


    • Nodular


    • Scirrhous constricting


    • Diffusely infiltrating


MICROSCOPIC PATHOLOGY


Histologic Features

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Jul 7, 2016 | Posted by in PATHOLOGY & LABORATORY MEDICINE | Comments Off on Adenocarcinoma of the Extrahepatic Bile Ducts

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