ICD-10 Code C83.04 – Small cell B-cell lymphoma, lymph nodes of axilla and upper limb (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code C83.04 – Small cell B-cell lymphoma, lymph nodes of axilla and upper limb
What it is
This code identifies small cell B-cell lymphoma involving lymph nodes in the axilla or upper limb. Use it when documentation specifies this lymphoma subtype and the nodal site is in the armpit or arm region.
Clinical signs
Findings often include enlarged lymph nodes in the axilla or upper extremity, sometimes discovered on exam or imaging. Clinical features vary; refer to documentation for the exact lymphoma subtype and anatomic site.
When to use this code
Use C83.04 when the record clearly states small cell B-cell lymphoma and identifies lymph nodes of the axilla or upper limb as the involved site. Apply it for confirmed diagnoses, specialty notes, pathology reports, or oncology assessments that match this wording. If the site is different or unspecified, check documentation.
Do not use for
Do not use this code for other lymphoma types, reactive lymphadenopathy, or lymphoma with a different nodal location. If the chart does not specify axillary or upper-limb nodes, do not assume this code.
Coding tip
Match both the histology and the exact lymph node site before assigning C83.04.