ICD-10 Code C82.21 – Follicular lymphoma grade III, unspecified, lymph nodes of head, face, and neck (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code C82.21 – Follicular lymphoma grade III, unspecified, lymph nodes of head, face, and neck
What it is
This code identifies follicular lymphoma grade III involving lymph nodes of the head, face, or neck, with the grade not further specified. Use it when the record confirms this lymphoma subtype and site.
Clinical signs
Typical findings include enlarged lymph nodes in the head and neck region, often painless and persistent. Clinical features vary; refer to documentation for biopsy, pathology, and staging details.
When to use this code
Use this code when the provider documents follicular lymphoma grade III and specifies lymph nodes of the head, face, or neck, but does not identify a more exact grade subtype. It is appropriate for confirmed diagnoses supported by pathology or oncology notes. Check documentation if the site is described only generally or if another nodal region is documented.
Do not use for
Do not use this code for follicular lymphoma in other lymph node regions or for grades other than III. If the record says unspecified lymphoma or a different non-Hodgkin lymphoma type, choose the documented diagnosis instead.
Coding tip
Confirm both the grade and the anatomic nodal site in the pathology or oncology report before assigning C82.21.