Cholangiocarcinoma

Cholangiocarcinoma is an aggressive malignancy of biliary epithelium that may arise anywhere in the biliary tract, from the intrahepatic biliary canaliculi to the terminus where the common bile duct enters the duodenum at the duodenal ampulla. Cholangiocarcinoma is classified by anatomical origin as intrahepatic cholangiocarcinoma (iCCA) or extrahepatic cholangiocarcinoma (eCCA); eCCA is subdivided into perihilar cholangiocarcinoma (pCCA) and distal cholangiocarcinoma (dCCA). More than 95% of cholangiocarcinomas are adenocarcinomas.

Several clinical conditions and premalignant lesions predispose to developing cholangiocarcinoma. The clinical presentation of cholangiocarcinoma will vary with the location and size of the tumor. Diagnosing cholangiocarcinoma can be difficult, particularly for extrahepatic lesions; available biopsy techniques lack diagnostic sensitivity. Surgical intervention is indicated even without a confirmatory tissue diagnosis in the appropriate clinical setting. All patients with suspected or confirmed cholangiocarcinoma should be evaluated for distant metastatic disease; almost 75% of patients have nonresectable or metastatic disease at presentation.

Carbohydrate cell-surface antigen 19-9 (CA 19-9) is a tumor marker excreted by the biliary epithelium that assists with assessing disease severity and surveillance monitoring. The overall prognosis of cholangiocarcinoma is poor, given the aggressive nature of the tumor and the usually advanced stage at presentation. Surgery is the only curative treatment modality; radiation and chemotherapy serve as adjuncts. Recent investigations into the molecular mechanisms underlying cholangiocarcinoma have yielded various targeted therapies that have improved outcomes and will hopefully improve patient care in the future.[3]