LAUSR

To the Editor, Rearrangements of PDGFRA, PDGFRB, FGFR1 or JAK2 are established features of myeloid/lymphoid neoplasms with eosinophilia (MLNEo).1 The rearrangement of the fmsrelated tyrosine kinase 3 (FLT3) gene should also be associated with MLNEo, and ETV6, SPTBN1, GOLGB1 and TRIP11 have been identified as FLT3 rearrangement partner genes2 (Figure S1). Cases of MLNEo with FLT3 rearrangement are rare but have a poor outcome. We encountered a patient who achieved a favourable longterm outcome by allogeneic haematopoietic stem cell transplantation (alloHSCT) and without using tyrosine kinase inhibitors, despite being refractory to conventional chemotherapy. The coiledcoil domain containing an 88C (CCDC88C)FLT3 translocation was identified in this patient who was diagnosed with myeloid neoplasm with Tcell lymphoblastic lymphoma (TLBL). Chronic myelomonocytic leukaemia (CMML) was one of the differential diagnoses for the current patient; the criteria of chronic myelomonocytic leukaemia included not having the specific genes, such as PDGFRA, if eosinophilia was present.1 The current case showed a FLT3 rearrangement, and therefore we considered a diagnosis of MLNEo as reasonable. The CCDC88CFLT3 translocation was identified in TLBL, CD34positive haematopoietic stem and multilineage cells.