Mycosis fungoides, lymph nodes of head, face, and neck

This code describes the involvement of lymph nodes in the head, face, and neck region by mycosis fungoides, a type of cutaneous T-cell lymphoma. It signifies the systemic spread of the disease beyond the skin, specifically to regional lymphatic structures.

Use this code when diagnostic imaging (e.g., CT, MRI, PET scan) or biopsy confirms mycosis fungoides involvement of lymph nodes located in the head, face, or neck. Documentation should clearly state the diagnosis of mycosis fungoides and the specific anatomical location of the affected lymph nodes.

• Always sequence a code for the primary cutaneous mycosis fungoides (e.g., C84.00) before this code, as this indicates metastatic involvement.
• Ensure documentation specifies "lymph nodes" and not just "skin lesions" in the head/neck area to justify this code.
• Distinguish from other lymphomas affecting head/neck lymph nodes; this code is specific to mycosis fungoides.