ICD-10 Code C83.91 – Non-follicular (diffuse) lymphoma, unspecified, lymph nodes of head, face, and neck (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code C83.91 – Non-follicular (diffuse) lymphoma, unspecified, lymph nodes of head, face, and neck
What it is
This code identifies a non-follicular, diffuse lymphoma affecting lymph nodes in the head, face, or neck region. Use it when the record names this lymphoma type but does not specify a more exact subtype.
Clinical signs
Common findings include enlarged, firm, or persistent lymph nodes in the head and neck area. Clinical features vary; refer to documentation for biopsy, imaging, or pathology details confirming lymphoma.
When to use this code
Use C83.91 when the provider documents non-follicular diffuse lymphoma and localizes it to lymph nodes of the head, face, or neck. It is appropriate when the subtype is unspecified and no more detailed lymphoma code is documented. Check documentation if the site or histology is unclear.
Do not use for
Do not use this code for follicular lymphoma, other specified lymphoma subtypes, or lymphoma in a different anatomic site. If the record names a more specific diagnosis, code that instead.
Coding tip
Confirm both the lymphoma type and the involved nodal region before assigning C83.91.