Z85.6

Personal history of leukemia

The ICD-10-CM code Z85.6 is a clinical status designation used to document that a patient has a past medical diagnosis of leukemia but is currently in complete remission and not undergoing active treatment for the primary malignancy. Leukemia is a group of cancers that typically begin in the bone marrow and result in high numbers of abnormal white blood cells. This history code is vital for guiding long-term survivorship care, which includes rigorous monitoring for disease recurrence, secondary primary malignancies—often arising from previous exposure to alkylating agents or ionizing radiation—and the assessment of late treatment effects. Clinical surveillance for individuals with a history of leukemia often involves serial complete blood counts (CBC), peripheral blood smears, and physical examinations to detect signs of lymphadenopathy or organomegaly. Documentation of this history informs risk assessment for subsequent medical procedures and assists in interpreting new hematological abnormalities.

Clinical Symptoms

  • Persistent fatigue or malaise
  • Unexplained weight loss
  • Increased frequency or severity of infections
  • Easy bruising or petechiae (pinpoint red spots on the skin)
  • Frequent nosebleeds or bleeding gums
  • Bone or joint pain and tenderness
  • Drenching night sweats
  • Recurrent low-grade fevers
  • Painless swelling of lymph nodes (lymphadenopathy)
  • Abdominal discomfort or fullness due to splenomegaly or hepatomegaly
  • Shortness of breath and pallor due to anemia

Common Causes

  • Genetic predispositions (e.g., Down syndrome, Li-Fraumeni syndrome)
  • Prior exposure to high-dose ionizing radiation
  • Previous treatment with cytotoxic chemotherapy (especially alkylating agents and topoisomerase II inhibitors)
  • Occupational or environmental exposure to benzene and other organic solvents
  • Evolution from a pre-existing myelodysplastic syndrome (MDS) or myeloproliferative neoplasm
  • Presence of specific chromosomal translocations (e.g., Philadelphia chromosome t(9;22))
  • Tobacco use (documented risk factor for acute myeloid leukemia)
  • Infection with Human T-lymphotropic virus type 1 (HTLV-1)

Documentation & Coding Tips

Distinguish between Personal History and In Remission status. If the leukemia type has a specific code for in remission (e.g., C91.01 for Acute Lymphoblastic Leukemia), that code should be utilized instead of Z85.6. Use Z85.6 only when a more specific remission code does not exist or when the patient is considered completely cured and no longer monitored for active disease recurrence.

Example: Patient seen for annual wellness exam. Documentation notes a history of Acute Promyelocytic Leukemia (APL) diagnosed in 2015, treated with ATRA and arsenic trioxide, completed in 2017. Currently in molecular remission with no clinical evidence of disease. Given the specific nature of APL and the lack of a distinct history code for that subtype, Z85.6 is assigned to capture the historical context of the hematologic malignancy during this preventative visit.

Billing Focus: Specificity of leukemia subtype and duration since last active treatment.

Explicitly document the completion of all active treatment modalities. To support the use of a history code rather than an active malignancy code, the clinical record must state that chemotherapy, immunotherapy, and radiation therapy have been concluded.

Example: The patient is a 55-year-old male with a history of Chronic Myeloid Leukemia (CML). He was managed on Imatinib for five years but achieved a deep molecular response and successfully discontinued therapy under a treatment-free remission protocol 24 months ago. No current antineoplastic agents are prescribed. Documenting the cessation of TKI therapy supports the transition from active CML (C92.10) to personal history (Z85.6).

Billing Focus: Treatment status (completed versus active).

Document late effects of leukemia treatment alongside the history code. Many survivors of leukemia suffer from long-term sequelae such as cardiomyopathy, peripheral neuropathy, or secondary malignancies. Linking these to the history of leukemia provides a complete clinical picture.

Example: Established patient presents with symptoms of Grade 2 peripheral sensory neuropathy. Assessment: Peripheral neuropathy likely secondary to historical treatment with Vincristine for childhood leukemia (Z85.6). Patient is 20 years post-treatment but continues to require gabapentin for symptom management. Documentation of the historical cause for current symptoms justifies the diagnostic workup for neurotoxicity.

Billing Focus: Causality between historical treatment and current symptoms.

Specify the type of leukemia in the narrative even if the ICD-10 code is generic. While Z85.6 is the catch-all for leukemia history, the clinical note should specify if the history was AML, ALL, CLL, or CML to guide appropriate surveillance protocols.

Example: Follow-up visit for 40-year-old female with personal history of Acute Myeloid Leukemia (AML), M3 subtype. Patient underwent successful bone marrow transplant in 2018. Current labs show stable chimerism and normal CBC. Using Z85.6 in the problem list while specifying AML and BMT status in the history of present illness ensures the level of surveillance (e.g., bone marrow biopsies) is clinically supported.

Billing Focus: Detailed clinical narrative supporting medical necessity for high-level labs.

Include bone marrow transplant (BMT) or Stem Cell Transplant status if applicable. Personal history of leukemia often involves prior transplants, which should be coded separately (e.g., Z94.81) alongside Z85.6 to reflect the full complexity of the patient's immune status.

Example: Patient presents for management of chronic GVHD. History: Acute Lymphoblastic Leukemia (Z85.6), status post allogeneic stem cell transplant in 2021 (Z94.81). Patient is no longer on chemotherapy but requires immunosuppression for GVHD. The combination of history of leukemia and transplant status accurately reflects the high risk for infection and ongoing medical complexity.

Billing Focus: Presence of transplant status (Z94.81) as a co-morbidity.

Relevant CPT Codes

Related Diagnoses

Hierarchy