Intrahepatic cholangiocarcinoma: role of imaging as a critical component for multi-disciplinary treatment approach.

Cholangiocarcinoma (CCA) is a unifying title granted to epithelial adenocarcinomas specific to the bile ducts making up 10-25% of all hepatobiliary malignancies. CCA is more appropriately classified based on anatomic site of origin within the biliary tract into intrahepatic cholangiocarcinoma (iCCA), peri-hilar (pCCA) cholangiocarcinoma, and distal cholangiocarcinoma (dCCA). Intrahepatic cholangiocarcinoma makes up 10-20% of CCA and originates within and/or proximal to the second order bile ducts. The incidence of iCCA has been rising overtime with up to 1.26 per 100,000 persons, per year in the United States and up to 3.3 per 100, 000 persons, per year affected globally. Risk factors include chronic hepatic inflammation secondary to viral hepatitis, alcohol/NASH cirrhosis, biliary cystic lesions, and endemic causes, among other less common genetic drivers. Given its rarity, the recognition and diagnosis of cholangiocarcinoma, iCCA specifically, remains challenging resulting in delays in treatment initiation or any treatment at all. Median overall survival (mOS) for iCCA remains low. Early diagnosis, and stage-based treatment approaches have evolved and are associated with improved survival. To this goal, a multi-disciplinary treatment approach has been demonstrated to improve patient outcomes by providing expert evaluation as it pertains to an accurate imaging and histologic diagnosis, staging, radiologic and surgical review for resectability, operative expertise, post operative care, as well as comprehensive knowledge and implementation of systemic/targeted or liver directed therapies. Here, we discuss the central role of imaging in the diagnosis of intrahepatic cholangiocarcinoma to implement a comprehensive treatment plan that frequently involves multiple disciplines to achieve the best outcome for each patient.