ICD-10 Code C81.21 – Mixed cellularity Hodgkin lymphoma, lymph nodes of head, face, and neck (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code C81.21 – Mixed cellularity Hodgkin lymphoma, lymph nodes of head, face, and neck
What it is
This code identifies mixed cellularity Hodgkin lymphoma when it involves lymph nodes in the head, face, or neck. It is a specific site-based diagnosis used when documentation confirms that an involved node region is in this area.
Clinical signs
Clinical features vary; refer to documentation. Hodgkin lymphoma is commonly described with enlarged lymph nodes, and pathology may specify the mixed cellularity subtype. You should code only when the record clearly links the subtype and nodal location.
When to use this code
Use C81.21 when the provider documents mixed cellularity Hodgkin lymphoma affecting lymph nodes of the head, face, or neck. This includes pathology, oncology, or discharge documentation that names both the histology and the anatomic site. If the site is broader or unclear, check documentation.
Do not use for
Do not use this code for other Hodgkin lymphoma subtypes or for unspecified nodal involvement. Also avoid it when the record names a different lymph node region, or when the diagnosis is only suspected. Check documentation.
Coding tip
Confirm both the mixed cellularity subtype and the head, face, or neck node location before assigning C81.21.