Table 1.

MD Anderson and World Health Organization definitions of accelerated phase and blast crisis in chronic myeloid leukemia [7–9]

Phase	MD Anderson criteria	World Health Organization criteria
Accelerated	Peripheral blood blasts ≥15% Peripheral blood blasts and promyelocytes ≥30% Peripheral blood basophils ≥20% Platelet count ≤100 × 109/L unrelated to therapy Clonal evolution	Blasts 10–19% of white blood cells in peripheral and/or nucleated bone marrow cells Peripheral blood basophils ≥20% Persistent thrombocytopenia (<100 × 109/L) unrelated to therapy or persistent thrombocytosis (>1,000 × 109/L) unresponsive to therapy Increasing spleen size and increasing white blood cell count unresponsive to therapy Cytogenetic evidence of clonal evolution
Blast crisis		Blasts ≥20% of peripheral blood white cells or of nucleated bone marrow cells Extramedullary blast proliferation Large foci or clusters in the bone marrow biopsy