Merkel cell carcinoma of unspecified part of face

This code signifies a rare and aggressive neuroendocrine carcinoma of the skin, specifically originating on the face, without further anatomical specification. Merkel cell carcinoma (MCC) is characterized by rapid growth and a high propensity for local recurrence and metastasis. It typically presents as a firm, shiny, flesh-colored to reddish-blue nodule.

Apply this code when the medical record clearly documents a diagnosis of Merkel cell carcinoma located on the face, but the specific facial subsite (e.g., nose, eyelid, cheek) is not specified. This code is appropriate when pathology confirms MCC and the physician's documentation indicates the facial region without further anatomical detail.

• Ensure the pathology report confirms Merkel cell carcinoma; do not use for other types of skin cancer.
• If a more specific facial subsite is documented (e.g., C4A.11 for eyelid, C4A.12 for ear), use that more precise code.
• Always sequence this code as a primary diagnosis when it is the reason for the encounter, unless another condition directly led to the MCC diagnosis (e.g., screening for a known genetic predisposition).