Acute myeloid leukemia associated with FGFR1 abnormalities.

Hematologic malignancies associated with FGFR1 abnormalities present in heterogeneous forms, including myeloproliferative neoplasm, acute myeloid leukemia (AML), T- or B-lineage lymphoblastic leukemia/lymphoma, and even mixed phenotype acute leukemia. In the present report, we describe three new cases of AML associated with FGFR1 abnormalities: AML with minimal differentiation with 45,XY,-7,t(8;13)(p11.2;q12), acute myelomonocytic leukemia with eosinophilia with 48,XY,t(8;9)(p11.2;q33),+19,+21, and AML with minimal differentiation with 46,XX,add(8)(p11.2). FGFR1 abnormalities were confirmed by fluorescence in situ hybridization. We reviewed the records of 19 patients reported from Asian countries, and found that approximately 40 % of cases manifested as acute leukemia associated with myeloid lineage, and 47 % were not accompanied with eosinophilia. These findings highlight the need for detection of FGFR1 abnormalities, not only in myeloproliferative disorder, but also in AML patients even without eosinophilia. The prognosis for this group of neoplasms is poor, and there is no recognized effective targeted treatment. Two patients, including our case, who received allogeneic hematopoietic stem cell transplantation (allo-HSCT) survived. Accumulation of long-term follow-up data can help determine the allo-HSCT protocol or the need for new therapeutic trials to improve the survival rate of patients with FGFR1 abnormalities.