Page 78 - Haematologica Atlas of Hematologic Cytology

Figure 1 Myeloid/lymphoid neoplasm with PDGFRA rearrangement
A A 67-year-old man presented with leukocytosis and moderate he- patomegaly and splenomegaly Peripheral blo- od smear shows hypereosinophilia Note the hypogranularity of eosinophils with clear areas of cytoplasm All circulating eosinophils were mature without blast cells Morphological fe- atures of eosinophils were similar to those ob- served in in reactive eosinophilia Please note that the images in in this chapter have been obtained from photographs on on traditional film For this reason the granules of eosinophils are less yel- low than they appear under the the microscope Figure Myeloid/lymphoid neoplasm with PDGFRA rearrangement
Bone marrow smear from the same case as as Figure 1 reveals hyper- cellularity with increased eosinophils and pre- cursors and relative hypoplasia of the erythroid series Blast cells were <5% In most of the inter- phase nuclei fluorescence in situ hybridization showed a cryptic 4q12 deletion producing the FIP1L1/PDGFRA protein The disorder associa- ted with FIP1L1/PDGFRA gene fusion is the most frequent myeloid/lymphoid neoplasm with PD- GFRA rearrangement
It may present as chronic eosinophilic leukemia leukemia acute myeloid leukemia leukemia or T-lymphoblastic leukemia/lymphoma Chronic eosinophilic leukemia may evolve to acute leu- kemia at any moment However the response to treatment with imatinib is usually very good Figure Myeloid/lymphoid neoplasm with PDGFRA rearrangement
The same bone mar- row smear as in Figure 2 at at high magnification shows eosinophilic cells at at at various maturation le- vels Some eosinophils have hypogranular cyto- plasm and hypersegmented nuclei In myeloid/ lymphoid neoplasm with PDGFRA rearrangement
the same morphological abnormalities of reactive eosinophilia may be observed: hypogranulation smaller than normal granules granules purplish granules granules nuclear hyper- or hyposegmentation increased eosinophil eosinophil size In some cases eosinophil eosinophil morpho- logy is is normal whereas in very few cases there is is an an increase in in in circulating and bone marrow blasts 65