Chronic myelomonocytic leukemia, in relapse

This code signifies a chronic myelomonocytic leukemia (CMML) that has returned or worsened after a period of remission or improvement. CMML is a clonal hematopoietic stem cell disorder characterized by persistent peripheral blood monocytosis and features of both myelodysplastic syndromes and myeloproliferative neoplasms.

Apply this code when documentation clearly indicates a diagnosis of CMML and specifies that the disease is currently in a state of relapse. This would typically be supported by physician notes detailing a recurrence of symptoms, an increase in blast count, or other laboratory findings consistent with disease progression after a period of stability or remission.

• Differentiate from CMML in remission (C93.11) or CMML, unspecified (C93.10).
• Ensure the medical record explicitly states "in relapse" for accurate code assignment.
• Always sequence this code as the primary diagnosis if it is the reason for the encounter.