Effective Response of Intrahepatic Cholangiocarcinoma to Pembrolizumab: A Case Report

The efficacy of pembrolizumab for intrahepatic cholangiocellular carcinoma (IHCCC) is not widely reported.We began pembrolizumab treatment in a 69-year-old male with recurrent IHCCC at 18 months after his surgery because of the proven microsatellite instability (MSI)-high status. The patient had partial response, with an 82.5% reduction at the end of 18 courses. Immunostaining of the primary tumor revealed intra-tumoral infiltration of both...