The presence of eosinophilia in acute myeloid leukemia (AML) suggests an underlying core binding factor (CBF) lesion, a platelet derived growth factor (PDGFR) translocation, or another rare translocation (such as ETV6-ABL1).
FMS-like tyrosine kinase-3 fragments from exon 14 to the end without any mutations or deletions have been reported to fuse to ETV6 (TEL) in a few cases of myeloid/lymphoid neoplasms with eosinophilia carrying a translocation t(12;13)(p13;q12).
We report here 2 male patients with ETV6-FLT3(+) myeloid/lymphoid neoplasms with eosinophilia who were treated with the multitargeted TK inhibitors sunitinib and sorafenib.
The fusion of TEL with platelet-derived growth factor receptor (PDGFR) beta (TPbeta) is found in a subset of patients with atypical myeloid neoplasms associated with eosinophilia and is the archetype of a larger group of hybrid receptors that are produced by rearrangements of PDGFR genes.
Fluorescence in situ hybridization (FISH) and reverse-transcription polymerase chain reaction (RT-PCR) detected the ETV6-PDGFRB fusion in a patient with chronic myelomonocytic leukemia characterized by bone marrow and peripheral blood eosinophilia and a four-way t(1;12;5;12)(p36;p13;q33;q24) on bone marrow cells.
We identified a novel human long fatty acyl CoA synthetase 2 gene, ACS2, as a new ETV6 fusion partner gene in a recurrent t(5;12)(q31;p13) translocation in a patient with refractory anemia with excess blasts (RAEB) with basophilia, a patient with acute myelogenous leukemia (AML) with eosinophilia, and a patient with acute eosinophilic leukemia (AEL).
Clinicohematological data in these studies as well as the restriction mapping of chromosomal breakpoints strongly suggest that (1) common features in MDSs involving the TEL gene are monocytosis and eosinophilia, (2) chromosomes other than no.