Table 8 Myeloid/lymphoid neoplasms with eosinophilia and TK fusion
From: A practical approach on the classifications of myeloid neoplasms and acute leukemia: WHO and ICC
WHO-HAEM5 | ICC | Most common fusion | Typical clinical and BM manifestations | Targeted therapy |
|---|---|---|---|---|
PDGFRA | PDGFRA | Cryptic deletion at 4q12/ FIP1L1::PDGFRA | Common: CEL-like BM with frequent extramedullary involvement Others: B-ALL/LL, AML or mast cell proliferations | Excellent response to TKI |
PDGFRB | PDGFRB | t(5;12)(q32;p13.2)/ ETV6::PDGFRB | Common: CEL-like or monocytosis with eosinophilia Others: ALL, AML or mast cell proliferations | Excellent response to TKI |
FGFR1 | FGFR1 | t(8;13)(p11.2;q12.1)/ ZMYM2::FGFR1 | Common: Extramedullary T-ALL/LL with BM MPN-like or blast phase of MPN; Trilineage MPAL not uncommon | High rate of response to FGFR inhibitor such as pemigatinib, especially for cases in chronic phase |
JAK2 | JAK2 | t(8;9)(p22;p24.1)/ PCM1::JAK2 | Often show characteristic pronormoblast clusters | Limited responses to ruxolitinib |
FLT3 | FLT3 | t(12;13)(p13.2;q12.2)/ ETV6::FLT3 | T-ALL/LL or myeloid sarcoma with CEL-like or MDS/MPN BM features | Various responses to specific FLT3 inhibitors |
ETV6::ABL1 | ETV6::ABL1 | t(9;12)(q34.1;p13.2)/ ETV6::ABL1 | CML-like with frequent eosinophilia in chronic or blast phase | Good response to TKI in chronic phase |
Other defined tyrosine kinase fusions | Not included | ETV6::FGFR2; ETV6::LYN; ETV6::NTRK3; RANBP2::ALK; BCR::RET; FGFR1OP::RET | Variable | Unknown |