ICD-10 Code C85.26 – Mediastinal (thymic) large B-cell lymphoma, intrapelvic lymph nodes (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code C85.26 – Mediastinal (thymic) large B-cell lymphoma, intrapelvic lymph nodes
What it is
This code identifies mediastinal (thymic) large B-cell lymphoma involving intrapelvic lymph nodes. Use it when the record documents this specific lymphoma subtype and the pelvic nodal site.
Clinical signs
Clinical features vary; refer to documentation. Large B-cell lymphoma may present with lymph node enlargement, and mediastinal disease can be associated with a chest mass or related compressive findings.
When to use this code
Use C85.26 when the provider clearly documents mediastinal (thymic) large B-cell lymphoma and specifies intrapelvic lymph node involvement. It may appear in pathology, oncology, or discharge documentation confirming this exact site and histology. If the record only says lymphoma without site detail, check documentation.
Do not use for
Do not use this code for unspecified lymphoma, other large B-cell lymphoma subtypes, or lymphoma limited to a different nodal region. If the mediastinal or intrapelvic site is not confirmed, check documentation.
Coding tip
Verify both the histologic subtype and the nodal site before assigning C85.26.