ICD-10 Code C84.Z5 – Other mature T/NK-cell lymphomas, lymph nodes of inguinal region and lower limb (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code C84.Z5 – Other mature T/NK-cell lymphomas, lymph nodes of inguinal region and lower limb
What it is
This code identifies a mature T-cell or NK-cell lymphoma involving lymph nodes in the inguinal region or lower limb. Use it when the record specifies this anatomic site and a diagnosis of other mature T/NK-cell lymphoma.
Clinical signs
Clinical features vary; refer to documentation. Commonly, lymphoma may present with enlarged inguinal nodes, localized swelling, or other signs of nodal disease, but the exact presentation depends on the confirmed subtype.
When to use this code
Use this code when the provider documents a mature T/NK-cell lymphoma affecting lymph nodes of the groin or lower extremity and no more specific ICD-10-CM code applies. It is appropriate for confirmed diagnoses, not merely suspected disease. Check documentation if the site or histology is unclear.
Do not use for
Do not use it for lymphomas outside the inguinal or lower-limb nodal region, or for non-mature B-cell lymphomas. If the chart does not confirm both the lymphoma type and site, check documentation.
Coding tip
Verify both the histology and the nodal location in the pathology or oncology note before assigning C84.Z5.