ICD-10 Code C86 – Other specified types of T/NK-cell lymphoma (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code C86 – Other specified types of T/NK-cell lymphoma
What it is
C86 identifies a group of lymphomas arising from T cells or natural killer cells that do not fit a more specific ICD-10 category. Use it when the record documents an “other specified” T/NK-cell lymphoma.
Clinical signs
Clinical features vary; refer to documentation. These lymphomas may present with lymph node enlargement, systemic symptoms, or extranodal disease, but the exact pattern depends on the subtype and site involved.
When to use this code
Use C86 when the clinician documents a T-cell or NK-cell lymphoma that is specified but not named in a more precise code. It also fits when pathology or oncology notes confirm an “other specified” T/NK-cell lymphoma. If the subtype is unclear, check documentation before coding.
Do not use for
Do not use C86 for unspecified lymphoma or for B-cell lymphomas. If the record names a more specific T/NK-cell lymphoma category, code that diagnosis instead.
Coding tip
Match the code to the exact lymphoma wording in the pathology or oncology note, and verify whether a more specific T/NK-cell code applies.