ICD-10 Code C84.02 – Mycosis fungoides, intrathoracic lymph nodes (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code C84.02 – Mycosis fungoides, intrathoracic lymph nodes
What it is
C84.02 identifies mycosis fungoides involving intrathoracic lymph nodes. Use it when documentation shows this cutaneous T-cell lymphoma has spread to lymph nodes inside the chest.
Clinical signs
Findings may include known mycosis fungoides with imaging or biopsy evidence of intrathoracic nodal involvement. Clinical features vary; refer to documentation.
When to use this code
Use this code when the provider documents mycosis fungoides affecting intrathoracic lymph nodes, such as mediastinal or hilar nodes. It applies when the record clearly links the lymphoma to those nodes. If the site is not specified, check documentation before assigning the code.
Do not use for
Do not use C84.02 for mycosis fungoides limited to skin or for other lymph node regions. If the chart only says “lymphoma” or “adenopathy,” check documentation.
Coding tip
Confirm the exact nodal site and that mycosis fungoides is specifically documented before coding C84.02.