Based on the TNM classification [21]. HA: Hepatic artery; PV: Portal vein. • T1: Tumor confined to the bile duct, with extension up to the muscle layer or fibrous tissue • T2a: Tumor invades ...

or unilateral extension to second-order biliary radicles with contralateral hepatic lobar atrophy; or main or bilateral portal venous involvement A clinical staging system devised by the ...