Continual progress of knowleges in hematopathology and genetics of hematologic tumors requires actualisation of widely accepted and presently used WHO classification of myeloid neoplasms published 8 years ago. However, the basic principles of this classification remain unchanged, therefore the authors of new WHO classification mention the "revision" of previous and not the introduction o new classification. The aim of this paper is to outline the most important changes of myeloid neoplasm diagnostics to pathologists, hematologists and other clinicians in Czech Republic and Slovakia. This review is based on several papers recently published by opinionleaders in this field.