Thrombocytosis (over 500.000/mmc) is classified as primary (clonal) or secondary (reactive). Increasing the number of platelets as response to various stimuli (inflammatory diseases, acute and recurrent bleeding, systemic infections or various types of malignancies) are considered to be reactive thrombocytosis [1,2,3].
Clonal or primary thrombocytosis (PT) is an abnormality of platelets production caused by clonal expansion of hematopoietic progenitor cells. In primary thrombocytosis autonomous platelets production is not regulated by physiological feedback mechanisms to maintain platelets count normal.