Blast Phase Chronic Myeloid Leukemia, BCR-ABL1 Positive

**Semantic type:** Neoplastic Process

**Definition:** An advanced phase of chronic myeloid leukemia. It is characterized by: 1. the presence of blasts in the peripheral blood or bone marrow that are at least 20% of the peripheral blood white cells or of the nucleated cells in the bone marrow respectively, or 2. an extramedullary proliferation of blasts, and/or 3. when there are large aggregates and clusters of blasts in the bone marrow biopsy specimen (adapted from WHO, 2001).

**Synonyms:** - Blast Phase CML - Blast Phase Chronic Granulocytic Leukemia - Blast Phase Chronic Myelocytic Leukemia - Blast Phase Chronic Myelogenous Leukemia - Blast Phase Chronic Myelogenous Leukemia, BCR-ABL1 Positive - Blast Phase Chronic Myelogenous Leukemia, BCR-ABL1 Positive - Blast Phase Chronic Myelogenous Leukemia, BCR::ABL1 Positive - Blast Phase Chronic Myeloid Leukemia - Blast Phase Chronic Myeloid Leukemia, BCR::ABL1 Positive - Blastic Phase CML - Blastic Phase Chronic Granulocytic Leukemia - Blastic Phase Chronic Myelocytic Leukemia - Blastic Phase Chronic Myelogenous Leukemia - Blastic Phase Chronic Myeloid Leukemia - blast crisis - blastic phase chronic myelogenous leukemia