Update on Lymphoma classification: The 2016 revised World Health Organization Classification of Hematopoietic and Lymphoid Neoplasms

A new monograph from the World Health Organization (WHO) on the classification of lymphoid neoplasms was published recently (Swerdlow SH, Campo E, Harris NL, et al. WHO Classification of Tumours of Haematopoietic and Lymphoid Tissues. 2017). As there were other volumes pending in the fourth edition of the WHO series, the monograph on lymphoid neoplasms was published as a major revision of the fourth edition instead of a new fifth edition. Although there were few major changes in terms of adding many new entities, some of the provisional entities in 2008 edition were made definitive, some terminology was changed, and there was a major expansion of genetic and molecular information. Notably, in this revision much emphasis is placed on the notion of precursor lesions diagnosed in very early stages of tumorigenesis.