Patients with PDGFRA-rearranged hematopoietic neoplasms typically present with chronic eosinophilic leukemia and rarely with acute myeloid leukemia or T-lymphoblastic lymphoma.
The 2016 World Health Organization (2016 WHO) classification of hematopoietic malignancies classifies neoplasms with a fusion between the FIP1L1 and PDGFRA genes in 4q12 into a group called "myeloid and lymphoid neoplasms with eosinophilia and abnormalities of PDGFRA, PDGFRB or FGFR1 or with PCM1-JAK2".
Rearrangement of the PDGFRA gene defines a distinct group of hematopoietic neoplasms that commonly present with persistent eosinophilia and are highly sensitive to low-dose imatinib mesylate treatment.
The FIP1L1-PDGFRA fusion gene is generated by a cryptic interstitial chromosomal deletion, del(4)(q12q12), which indicates that these cases are clonal hematopoietic malignancies and should be reclassified as chronic eosinophilic leukemias based on current World Health Organization recommendations.