A revised 4 edition WHO Classification of Tumors of Hematopoietic and Lymphoid Tissues, 2017: myeloid neoplasms

The paper presents new molecular data, the principles of the classification of myeloid neoplasms, and criteria for their diagnosis according to the new edition of the WHO Classification of Tumors of Hematopoietic and Lymphoid Tissues, 2017. Current concepts of clonal hematopoiesis and models of clonal evolution are presented to characterize the common features of the molecular pathogenesis of myeloid neoplasms. There are new data and general principles of diagnosis of myeloid neoplasms: Ph-negative myeloproliferative diseases, myelodysplastic syndromes, myeloid/lymphoid neoplasms with eosinophilia and rearrangements of PDGFRA, PDGFRB, FGFR1, and PCM1-JAK2, diseases from the group of myelodysplastic/myeloproliferative diseases. Emphasis is laid on the possibilities and limitations of pathological differential diagnosis when a pathologist examines bone marrow trepanobiopsy specimens in his/her routine work.