ICD-10 Code C83.3 – Diffuse large B-cell lymphoma (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code C83.3 – Diffuse large B-cell lymphoma
What it is
C83.3 identifies diffuse large B-cell lymphoma, an aggressive non-Hodgkin lymphoma that starts in B lymphocytes. Use it when the record specifically documents this diagnosis.
Clinical signs
Clinical features vary; refer to documentation. Common findings include rapidly enlarging lymph nodes, extranodal masses, and “B symptoms” such as fever, night sweats, or weight loss.
When to use this code
Use C83.3 when the provider documents diffuse large B-cell lymphoma as the confirmed diagnosis. It may appear in pathology, oncology, or discharge records describing nodal or extranodal disease. If the record only says “lymphoma” or the subtype is unclear, check documentation before coding.
Do not use for
Do not use this code for other non-Hodgkin lymphoma subtypes, Hodgkin lymphoma, or unspecified lymphoma. If the documentation does not identify diffuse large B-cell lymphoma, choose a more accurate code.
Coding tip
Code from the final pathology or oncologist’s diagnosis, and verify laterality or site details only when the chart supports them.