Decreased intratumoral arteries reflect portal tract destruction and aggressive characteristics in intrahepatic cholangiocarcinoma

To assess the relationship between arterial blood supply and the progression of intrahepatic cholangiocarcinoma (ICC). The intratumoral arterial vessel density (AVD) was assessed in 76 cases of mass-forming type of ICC using anti-h-caldesmon antibody, a marker of smooth muscle cells, and AVD compared with pathological findings. AVD was directly correlated with the presence of intratumoral portal tracts (P < 0.0001) and inversely correlated with the grade of tumour necrosis (P = 0.0013). AVD was inversely correlated with vascular invasion and lymph node metastasis (P = 0.0159 and P = 0.0023, respectively). The hilar type of ICC had lower AVD regardless of tumour size, whereas the peripheral type with high AVD showed branching ductular formation composed of cuboidal cells with mild nuclear atypia. AVD was found to be an independent prognostic factor on multivariate survival analysis (P = 0.0013). This study demonstrates that intratumoral arterial vessels reflect engulfed portal tracts in ICC and decreased arterial vessels indicate aggressive tumour behaviour. Our results could contribute to clinical tumour staging and more effective therapy.