Chronic Myeloid Leukemia, Philadelphia Chromosome Negative, BCR-ABL1 Positive

**Semantic type:** Neoplastic Process

**Definition:** A chronic myeloid leukemia that does not have the characteristic t(9;22)(q34;q11.2) translocation but it has either a variant translocation or a cryptic translocation that cannot be detected by conventional cytogenetic analysis. In such cases the BCR-ABL1 fusion gene is always detected by RT-PCR, FISH, or Southern blot analysis.

**Synonyms:** - Chronic Myeloid Leukemia, Philadelphia Chromosome Negative, BCR::ABL1 Positive - Ph Negative CML - Ph Negative Chronic Myelogenous Leukemia - Ph' Chromosome Negative Chronic Granulocytic Leukemia - Ph' Chromosome Negative Chronic Myelocytic Leukemia - Ph' Chromosome Negative Chronic Myeloid Leukemia - Ph' Negative Chronic Granulocytic Leukemia - Ph- CML - Ph- Chronic Myelogenous Leukemia - Ph1 Chromosome Negative Chronic Myelocytic Leukemia - Ph1 Chromosome Negative Chronic Myelogenous Leukemia - Philadelphia Chromosome Negative BCR-ABL1 Positive Chronic Myelogenous Leukemia - Philadelphia Chromosome Negative CML - Philadelphia Chromosome Negative Chronic Granulocytic Leukemia - Philadelphia Chromosome Negative Chronic Myelocytic Leukemia - Philadelphia Chromosome Negative Chronic Myelogenous Leukemia - Philadelphia Chromosome Negative Chronic Myeloid Leukemia - Philadelphia Chromosome Negative, BCR-ABL1 Positive Chronic Myelogenous Leukemia - Philadelphia Chromosome Negative, BCR-ABL1 Positive Chronic Myelogenous Leukemia - Philadelphia Chromosome Negative, BCR::ABL1 Positive Chronic Myelogenous Leukemia