Adult T-cell lymphoma/leukemia (HTLV-1-assoc), in relapse

This code identifies a specific type of mature T-cell non-Hodgkin lymphoma and leukemia, directly linked to Human T-lymphotropic virus type 1 (HTLV-1) infection, that has recurred after a period of remission. It signifies the re-emergence of the disease in an adult patient.

Apply this code when documentation explicitly states a diagnosis of Adult T-cell lymphoma/leukemia (HTLV-1-associated) and specifies that the disease is currently in relapse. This typically follows a period of successful treatment and subsequent recurrence.

• Ensure the documentation clearly specifies "relapse" and not "remission" or "unspecified."
• Verify the patient is an "adult" as per the code description; pediatric cases would be coded differently if applicable.
• Confirm the HTLV-1 association is documented, as other T-cell lymphomas exist without this etiology.