Stage IV perihilar cholangiocarcinoma with loss of expression of MSH2 and MSH6: hereditary cancer syndrome?

We present the case of a 69-year-old male diagnosed with stage IV perihilar cholangiocarcinoma with loss of expression of MSH2 and MSH6 proteins, but somatic wild type MSH2 and MSH6 genes with Oncomine Comprehensive Assay (OCA) genomic sequencing panel. In his cancer family history, there was a maternal aunt with sigmoid colon adenocarcinoma also missing MSH2 and MSH6 protein expression. Subsequently, we will discuss whether or not we are facing a hereditary cancer syndrome.