Abstract
Myeloid and lymphoid neoplasms associated with FGFR1 abnormalities (MLN-FGFR1 abnormalities) are rare hematologic malignancies associated with chromosome 8p11.2 abnormalities. Translocations of 8p11.2 were detected in 10 of 17,039 (0.06%) unique patient cytogenetic studies performed at nine institutions in Japan. No inversions or insertions of 8p11.2 were detected. Among the 10 patients with 8p11.2 translocations, three patients were diagnosed with MLN-FGFR1 abnormalities, which were confirmed by FISH analysis. Peripheral blood eosinophilia was observed in all three patients, and all progressed to AML or T-lymphoblastic lymphoma/leukemia. The prevalence of 8p11.2 translocations in clinical practice and the proportion of MLN-FGFR1 abnormalities in patients with 8p11.2 translocations in Japan were consistent with those in previous reports from Western countries.