Hairy cell leukemia, in remission

This code signifies a diagnosis of hairy cell leukemia (HCL) where the disease is currently in a state of remission. HCL is a rare, slow-growing cancer of the blood and bone marrow, characterized by abnormal B lymphocytes with hair-like projections. "In remission" indicates that the signs and symptoms of the cancer have significantly decreased or disappeared, often due to successful treatment.

Apply this code when documentation clearly states a patient has a history of hairy cell leukemia and is currently in remission. This typically follows a period of active disease and successful therapeutic intervention, such as chemotherapy or immunotherapy. Supporting documentation would include physician notes confirming remission status, often based on bone marrow biopsies, blood counts, and physical examination findings.

• Always confirm the specific type of leukemia (hairy cell) and the remission status from the physician's documentation.
• Do not confuse this with active hairy cell leukemia (C91.40) or other types of leukemia in remission.
• If the patient is still receiving maintenance therapy for the leukemia in remission, ensure that the appropriate Z code for long-term drug therapy is also reported.