Bilineal T lymphoblastic and myeloid blast transformation in chronic myeloid leukemia with TP53 mutation-an uncommon...

Bilineal blast transformation of myeloid and T lymphoid type is a rare event in chronic myeloid leukemia. Here, we report a case in which an adult presented with high white cell counts and lymphadenopathy. Bone marrow studies confirmed the presence of 9 and 22 chromosomal translocation, and a diagnosis of chronic myeloid leukemia in chronic phase was made. Examination of a lymph node showed both myeloid and T lymphoblastoid blast crisis. Molecular studies demonstrated the presence of BCR-ABL fusion transcripts in both the myeloid and the T lymphoblastic component, indicating that the myeloid and T lymphoid blast crisis components shared common progenitors. TP53 deletion was demonstrated by fluorescence in situ hybridization.