ICD-10 Code C82.99 – Follicular lymphoma, unspecified, extranodal and solid organ sites (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code C82.99 – Follicular lymphoma, unspecified, extranodal and solid organ sites
What it is
C82.99 identifies follicular lymphoma when the site is extranodal or a solid organ and the record does not specify a more exact location. Use this code for a documented follicular lymphoma outside lymph nodes, when the site detail is limited.
Clinical signs
Clinical features vary; refer to documentation. Follicular lymphoma is a B-cell non-Hodgkin lymphoma that may present with mass effect, organ involvement, or incidental imaging findings, depending on the extranodal site.
When to use this code
Use C82.99 when the provider documents follicular lymphoma involving an extranodal or solid organ site but does not name a more specific location. It also fits when the chart says “unspecified” site or the exact organ is not available. Verify that the diagnosis is follicular lymphoma, not another lymphoma subtype.
Do not use for
Do not use this code for follicular lymphoma limited to lymph nodes or for a clearly documented specific extranodal site with a more precise code. Check documentation if the record names another lymphoma type or a different primary cancer.
Coding tip
Code the most specific site documented; if the extranodal organ is named, confirm whether a more detailed ICD-10-CM option applies.