ICD-10 Code C88.2 – Heavy chain disease (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code C88.2 – Heavy chain disease
What it is
C88.2 identifies heavy chain disease, a rare B-cell disorder in which abnormal immunoglobulin heavy chains are produced. It is a hematologic malignancy or lymphoproliferative condition, depending on the documented subtype.
Clinical signs
Clinical features vary; refer to documentation. Patients may present with lymphadenopathy, splenomegaly, anemia, weight loss, or other signs of lymphoid involvement, depending on the heavy chain disease subtype.
When to use this code
Use C88.2 when the provider documents heavy chain disease, including alpha, gamma, or mu heavy chain disease, if the record does not specify a more precise diagnosis. Code it from confirmed clinical documentation, pathology, or hematology assessment.
Do not assign it for general monoclonal gammopathy or unspecified lymphoma unless heavy chain disease is explicitly stated. Check documentation when the chart only mentions abnormal immunoglobulins or a suspected plasma cell disorder.
Do not use for
Do not use C88.2 for multiple myeloma, Waldenström macroglobulinemia, or other lymphomas unless heavy chain disease is documented. Check documentation when the diagnosis is uncertain or only suspected.
Coding tip
Code the most specific heavy chain disease type documented, and query when the record only says “heavy chain disorder” or gives incomplete pathology.