The 2015 WHO Classification of Tumors of the Heart and Pericardium.

This article reviews the nomenclature of benign and malignant neoplasm of the heart and pericardium in the 4th edition of the World Health Organization's Classification, with emphasis on differences since the 3rd edition of 2004. The tumours are divided into benign, malignant, and intermediate tumors of uncertain behavior, with separate sections on germ cell tumours and tumors of the pericardium. There are important updates in the sarcoma classification, with emphasis on the most common site, the left atrium. The importance of the new genetic finding in cardiac myxomas, namely somatic mutations in the PRKAR1A gene underscores the importance of this alteration in the pathogenesis of these tumors. Challenges on the classification of each entity are discussed.