The favorable prognosis after operative resection of hypervascular intrahepatic cholangiocarcinoma: A clinicopathologic and immunohistochemical study.

Background: The aim of this study was to clarify the clinicopathologic characteristics of hypervascular intrahepatic cholangiocarcinoma (ICC).

Methods: Seventy patients with a mass-forming type ICC underwent hepatectomy between 2003 and 2013. These patients were divided into 2 groups and compared based on findings during the late arterial phase of computed tomography: hypervascular ICC (the mean computed tomography value of the tumor ≥ that of the nontumorous liver parenchyma, n = 21), and hypovascular ICC (n = 49).

Results: The overall survival of the hypervascular group was better than that of the hypovascular group (5-year survival: 63% vs 35%, respectively, P = .046). Pathologic examinations showed less lymph node metastasis (0% vs 39%), lymphatic invasion (14% vs 57%), mucin secretion (19% vs 61%), tumor necrosis (24% vs 57%), and combined periductal infiltration (0% vs 27%), P ≤ .01 each, in the hypervascular group. The microscopic bile ductular feature was more frequent in the hypervascular group (57% vs 29%, P = .023). Immunohistochemical analysis revealed that the hypervascular group had greater immunoreactivity to neural cell adhesion molecule (71% vs 37%, P = .008) and a lesser S100P immunoreactivity (33% vs 73%, P = .002). Multivariate analysis revealed that neural cell adhesion molecule reactivity (P = .018) was independently associated with the hypervascular group.

Conclusion: Tumor vascularity predicts the aggressiveness of ICC. In most patients with hypervascular ICC, the tumor has a less invasive nature. Furthermore, the prognosis after resection in patients with hypervascular ICC is significantly better than in patients with hypovascular ICC.