ICD-10 Code C83.31 – Diffuse large B-cell lymphoma, lymph nodes of head, face, and neck (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code C83.31 – Diffuse large B-cell lymphoma, lymph nodes of head, face, and neck
What it is
This code identifies diffuse large B-cell lymphoma involving lymph nodes in the head, face, or neck. It is used when the diagnosis specifically localizes this aggressive non-Hodgkin lymphoma to those nodal sites.
Clinical signs
Typical findings include enlarged lymph nodes in the neck or nearby facial regions, often with a rapidly enlarging mass. Clinical features vary; refer to documentation for biopsy confirmation and exact nodal location.
When to use this code
Use C83.31 when the record states diffuse large B-cell lymphoma and clearly documents lymph node involvement of the head, face, or neck. Apply it for confirmed primary or involved nodal disease in these sites. Check documentation if the site is broader or unspecified.
Do not use for
Do not use this code for lymphoma in other lymph node regions or for unspecified diffuse large B-cell lymphoma. If the chart only says “B-cell lymphoma” or does not identify the nodal site, check documentation.
Coding tip
Code the exact anatomic site from pathology or oncology notes; the nodal location drives this code.