Merkel cell carcinoma (MCC) is an uncommon and aggressive cutaneous neoplasm that lacks distinguishing clinical features. More than half of Merkel cell carcinomas (MCCs) occur in the head and neck of elderly people in areas of actinically damaged skin. The most common site of occurrence is the periorbital region. Merkel cell carcinoma (MCC) has a propensity to recur and to cause local and distant metastases. Distant metastases indicate a condition that is nearly always fatal.
The diagnosis is based on a combination of light microscopy, electron microscopy, and immunohistochemistry. Current treatment consists of wide local excision with adjuvant irradiation. Neck dissection is used for clinically positive nodes, and chemotherapy is given for advanced disease.