Ph-Negative Chronic Myeloid Leukemia and Fusion Signal bcr/abl on Chromosome 9

Abstract

We report a 10-year-old girl with Ph-negative chronic myeloid leukemia (CML) and fusion signal bcr/abl on chromosome 9. She complained of right femoral swelling. She was diagnosed as having CML in accelerated phase by laboratory investigations and bone marrow. The biopsy of the femoral swelling showed granulocytes at all stages of development. Cytogenetic studies (G-banding) revealed a 46, XX normal female karyotype in bone marrow cells. Fluorescence in situ hybridization studies revealed the bcr/abl fusion signal on chromosome 9, two bcr signals both on chromosomes 22 and an abl signal on chromosome 9. Molecular studies (RT-PCR) revealed the presence of a b3a2 rearrangement. An allogeneic bone marrow transplantation (BMT) from her HLA-identical sister was performed 6 months after diagnosis. She developed a lymphoid blast crisis 3 months after BMT. Despite attempts at chemotherapy and donor lymphocyte infusion twice, the disease progressed and she died 14 months after transplant. In past reports, the prognosis of the patients with both fused bcr/abl gene located on chromosome 9 and extramedullary disease is poor. The correlation between fused bcr/abl gene located on chromosome 9 and extramedullary disease is unknown.