ICD-10 Code C85.15 – Unspecified B-cell lymphoma, lymph nodes of inguinal region and lower limb (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code C85.15 – Unspecified B-cell lymphoma, lymph nodes of inguinal region and lower limb
What it is
This code identifies a B-cell lymphoma in the inguinal lymph nodes or lower limb region when the subtype is not specified. Use it when the record confirms lymphoma involvement at that site but does not name a more specific B-cell type.
Clinical signs
Findings often include enlarged inguinal nodes or a mass in the lower limb region, with pathology showing lymphoma. Clinical features vary; refer to documentation.
When to use this code
Use this code when the provider documents an unspecified B-cell lymphoma affecting lymph nodes of the groin or lower extremity and no further subtype is named. It also fits pathology or oncology notes that localize disease to this nodal region without a more specific diagnosis. If the record later identifies a defined lymphoma type, code that instead.
Do not use for
Do not use it for lymphomas outside the inguinal or lower limb nodal region, or when the documentation names a specific B-cell lymphoma subtype. Check documentation.
Coding tip
Confirm both the anatomic site and that the lymphoma is truly unspecified before assigning C85.15.