What are the stages of chronic myeloid leukemia?

• A. Chronic phase, accelerated phase, and blast crisis (acute leukemia)
• B. Initial phase, progressive phase, terminal phase
• C. Acute phase, chronic phase
• D. Remission, relapse

Answer: (A)

Chronic myeloid leukemia progresses through three clinical phases: chronic phase, accelerated phase, and blast crisis. In the chronic phase the disease grows slowly and many patients have few symptoms, with relatively low blast counts in the marrow and blood. If it advances, the accelerated phase shows worsening blood counts, more symptoms, and rising blasts—typically in the range of about 10–19% in marrow or blood. The final phase is blast crisis, where blasts are abundant (usually 20% or more) and the leukemia behaves like an acute leukemia, requiring aggressive therapy. This blast-phase transformation marks a shift to a rapidly progressing, high-risk state. The other options don’t reflect this established sequence, and they may describe remission/relapse or nonstandard phase names that don’t capture the progressive nature of CML.