ICD-10 Code C84.Z7 – Other mature T/NK-cell lymphomas, spleen (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code C84.Z7 – Other mature T/NK-cell lymphomas, spleen
What it is
This code identifies a mature T-cell or natural killer (NK)-cell lymphoma involving the spleen. Use it when documentation specifies this splenic site and the lymphoma is not otherwise classified elsewhere.
Clinical signs
Clinical features vary; refer to documentation. Commonly recorded findings may include splenomegaly, abdominal discomfort, cytopenias, or systemic “B” symptoms in a confirmed T/NK-cell lymphoma.
When to use this code
Use C84.Z7 when the provider documents a mature T/NK-cell lymphoma with splenic involvement and does not assign a more specific subtype. It also fits cases where the spleen is the documented primary site or dominant site of disease. Check documentation if the record only says lymphoma, splenic mass, or enlarged spleen without histologic confirmation.
Do not use for
Do not use this code for B-cell lymphomas, Hodgkin lymphoma, or unspecified lymphoma without T/NK-cell confirmation. If the spleen is involved by another malignancy or the diagnosis is unclear, check documentation.
Coding tip
Code the documented histology and splenic site together, and do not assume T/NK-cell lineage from imaging alone.