ICD-10 Code C84.94 – Mature T/NK-cell lymphomas, unspecified, lymph nodes of axilla and upper limb (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code C84.94 – Mature T/NK-cell lymphomas, unspecified, lymph nodes of axilla and upper limb
What it is
C84.94 identifies a mature T-cell or NK-cell lymphoma involving lymph nodes of the axilla or upper limb, when the subtype is not specified. Use it when documentation confirms this site and lymphoma type but does not name a more specific entity.
Clinical signs
Clinical features vary; refer to documentation. Commonly recorded findings may include enlarged axillary or upper-extremity lymph nodes, persistent lymphadenopathy, or biopsy-confirmed lymphoma involving those nodes.
When to use this code
Use this code when the provider documents mature T/NK-cell lymphoma in axillary or upper-limb lymph nodes and does not specify a more precise subtype. It also fits pathology or oncology notes that clearly localize disease to these nodes. If the record gives another site or a different lymphoma classification, choose the documented code instead.
Do not use for
Do not use C84.94 for unspecified lymphoma without T/NK-cell lineage or for disease in non-axillary, non-upper-limb nodes. Check documentation if the site is primary skin, blood, or another lymph node region.
Coding tip
Verify both the lymphoma lineage and the nodal site before coding; if either is unclear, check documentation.