Histologic, cytogenetic, and molecular characteristics of the MLN-EO and a G3BP1-PDGFRB fusion. Hematoxylin and eosin–stained bone marrow core biopsy at low magnification (×4) (A) and high magnification (×40) (B), showing a hypercellular myeloid-predominant marrow with markedly increased eosinophilic forms. (C) May-Grünwald-Giemsa–stained bone marrow aspirate showing eosinophils in various stages of differentiation (magnification, ×100). (D) G-banding karyotype showing trisomy 8. (E) Schematic representation of the fusion transcript between the 5′UTR of G3BP1 and exons 12 of PDGFRB, detected by targeted AMP sequencing off RNA.