Survival-associated histologic spreading modes of operable intrahepatic, peripheral-type cholangiocarcinomas

We investigated survival-associated histologic and metastatic spreading modes of intrahepatic, peripheral-type cholangiocarcinomas resected to contribute to surgical control of the tumor. Previous results have been mostly obtained from autopsies, reflecting the terminal status of patients. We clinicopathologically reviewed the resected 20 intrahepatic, peripheral-type cholangiocarcinomas and investigated the histologic findings of resected specimens and medical records to assess spreading modes along with patients' survival. The carcinoma cells superficially spread in the ductal epithelium in 75%, infiltrated along Glisson's system and migrated multidirectionally in 100%, and permeated the vascular network in 80%. The cumulative survival rate significantly related to vascular permeation, extrahepatic metastases, and lymphatic, neural, and nodal involvement but not to ductal spread, tumor size (cutoff size 5 cm), or intrahepatic metastases by the log-rank test. The patients with lymphatic, neural, or nodal involvement died early after surgery. Practically, only vascular permeation was identified as a significant independent variable for survival using multivariate analysis. Peripheral cholangiocarcinomas spread mainly in three modes: ductal spread, infiltration along Glisson's system, and vascular permeation. In the practically operable cases, vascular permeation is closely related to survival, and intrahepatic metastasis may be surgically controlled to some degree.