ICD-10 Code C82.31 – Follicular lymphoma grade IIIa, lymph nodes of head, face, and neck (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code C82.31 – Follicular lymphoma grade IIIa, lymph nodes of head, face, and neck
What it is
This code identifies follicular lymphoma grade IIIa involving lymph nodes in the head, face, or neck. Use it when documentation specifies this histologic grade and anatomic site.
Clinical signs
Findings often include enlarged lymph nodes in the neck or nearby regions, with pathology confirming follicular lymphoma grade IIIa. Clinical features vary; refer to documentation.
When to use this code
Use C82.31 when the provider documents follicular lymphoma grade IIIa and states the involved lymph nodes are in the head, face, or neck. Code from the pathology or oncology note, not from suspicion alone.
If the record only says follicular lymphoma without grade or site, check documentation before assigning this code. Confirm whether the diagnosis is confirmed, current, and specific enough for coding.
Do not use for
Do not use this code for other follicular lymphoma grades or for nodal disease in a different body region. Do not use it when the site is unspecified or not documented.
Coding tip
Match both the grade and lymph node location exactly; if either is missing, query the record before coding.