Case of cryptic TNIP1::PDGFRB rearrangement presenting with myelodysplastic syndrome achieved hematologic and cytogenetic remission with low-dose imatinib plus decitabine therapy

For a long time, FIP1L1::PDGFRA fusion seems to be the only cryptic rearrangement of myeloid/lymphoid neoplasm with tyrosine kinase gene fusions. Recently, with the wide application of RNA sequencing, more cryptic rearrangements of other TK genes have been identified, especially the PDGFRB. Here we report a case of myelodysplastic syndrome with severe thrombocytopenia. Conventional karyotype analysis revealed a t (5;19) (q33; p13.2) but no PDGFRB rearrangement was detected by the PDGFRB break-apart probe. The TNIP1::PDGFRB fusion was eventually found by RNA sequencing, leading us to treat with low-dose imatinib plus decitabine, and the patient achieved hematologic improvement and cytogenetic remission.