With the revision of the 2008 World Health Organization (WHO) classification of myeloid neoplasms, a new category entitled Myeloid and lymphoid neoplasms with eosinophilia and abnormalities of platelet-derived growth factor receptor alpha (PDGFRA), platelet derived growth factor receptor beta (PDGFRB), or fibroblast growth factor receptor 1 (FGFR1) was introduced [24]. This evidence concerns the gene FGFR1 and Increased total eosinophil count.