CK 20-positive and CK 7-negative Merkel cell carcinoma of the cheek

Merkel cell carcinomas (MCCs) are uncommon, highly malignant skin tumors that develop in sun-exposed areas of the skin. Most of the MCCs are CK 20-positive and CK 7-negative such as our case. About 80% of Merkel cell carcinoma is associated with Merkel cell polyomavirus.