Updates in the diagnosis of combined hepatocellular-cholangiocarcinoma.

Combined hepatocellular-cholangiocarcinoma (cHCC-CCA) is a rare primary liver carcinoma showing variable degrees of differentiation toward hepatocellular and cholangiocellular carcinoma. Its great heterogeneity in term of morphology, immunophenotype, molecular, radiological and clinical features represents a challenge still to overcome. The multidisciplinary 2018 International Consensus on the nomenclature of cHCC-CCA allowed to define key issues of this entity. Here we review the historical controversies of cHCC-CCA, resume the key elements of the 2018 consensus, now incorporated in the 2019 WHO classification, and propose a short survival guide to help surgical pathologists facing cHCC-CCA in their routine workup.