ICD-10 Code C84.98 – Mature T/NK-cell lymphomas, unspecified, lymph nodes of multiple sites (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code C84.98 – Mature T/NK-cell lymphomas, unspecified, lymph nodes of multiple sites
What it is
C84.98 identifies a mature T-cell or natural killer cell lymphoma when the subtype is not specified and the disease involves lymph nodes at multiple sites. Use it for documented nodal involvement without a more precise lymphoma classification.
Clinical signs
Clinical features vary; refer to documentation. Commonly recorded findings include enlarged lymph nodes in more than one region and pathology confirming a mature T/NK-cell lymphoma, but the exact subtype is not named.
When to use this code
Use this code when the provider documents mature T/NK-cell lymphoma, specifies multiple lymph node sites, and does not identify a more specific histology or site code. It is appropriate for confirmed lymphoma involving nodal disease across several regions. Check documentation if the record mentions extranodal disease or a defined subtype.
Do not use for
Do not use C84.98 for a lymphoma with a specific mature T-cell or NK-cell subtype, or when the disease is limited to a single lymph node site. Check documentation if the record instead describes leukemia, Hodgkin lymphoma, or an unspecified lymph node disorder.
Coding tip
Code the most specific lymphoma term documented first; only use C84.98 when the subtype remains unspecified and multiple nodal sites are clearly stated.