Merkel cell carcinoma of left lower eyelid, inc canthus

This code signifies a rare and aggressive neuroendocrine tumor, Merkel cell carcinoma, specifically located on the left lower eyelid, encompassing the canthal region. This malignancy originates from Merkel cells in the skin and is characterized by rapid growth and a high propensity for metastasis.

Apply this code when documentation clearly indicates a confirmed diagnosis of Merkel cell carcinoma affecting the left lower eyelid, including any involvement of the inner or outer canthus. This code is appropriate for initial diagnoses, as well as for subsequent encounters related to the primary tumor site.

• Ensure the laterality (left) and specific eyelid involvement (lower) are explicitly documented.
• Verify that the pathology report confirms Merkel cell carcinoma, not another type of skin cancer.
• Code any associated metastases separately, following the primary tumor code.