Merkel cell carcinoma of left upper eyelid, inc canthus

This code signifies a rare and aggressive neuroendocrine carcinoma, specifically Merkel cell carcinoma, originating in the left upper eyelid, including the canthal region. This malignancy is characterized by rapid growth and a high propensity for local recurrence and metastasis.

Apply this code when documentation clearly specifies a confirmed diagnosis of Merkel cell carcinoma affecting the left upper eyelid, encompassing any involvement of the canthus. This diagnosis is typically established through biopsy and histopathological examination.

• Ensure the laterality (left) and specific anatomical site (upper eyelid, including canthus) are explicitly documented.
• Do not use this code for other types of eyelid malignancies, such as basal cell or squamous cell carcinoma.
• Sequence this code as the primary diagnosis when it is the reason for the encounter, followed by any relevant secondary diagnoses or complications.