ICD-10 Code C85.10 – Unspecified B-cell lymphoma, unspecified site (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code C85.10 – Unspecified B-cell lymphoma, unspecified site
What it is
C85.10 identifies a B-cell lymphoma when the record confirms the diagnosis but does not specify the exact subtype or the primary site. Use it when documentation supports lymphoma, yet details remain incomplete.
Clinical signs
Clinical features vary; refer to documentation. Commonly recorded findings include enlarged lymph nodes, constitutional symptoms, or other signs of lymphoma, but the exact presentation and site must be documented.
When to use this code
Use C85.10 when the provider documents unspecified B-cell lymphoma and does not name a more specific histology or anatomic site. It also fits when pathology or oncology notes confirm B-cell lymphoma, but the chart lacks further detail. If the site is known, code that information instead.
Do not use for
Do not use this code when the lymphoma type is more specific, such as diffuse large B-cell lymphoma or follicular lymphoma. Do not assign it if the record identifies a definite primary site or if documentation is incomplete and needs clarification.
Coding tip
Check pathology, oncology, and discharge notes first; if subtype or site is documented, code the more specific option instead of C85.10.