Merkel cell carcinoma (MCC) is an aggressive form of skin cancer that usually occurs in older individuals, often with a history of prolonged sun exposure. This rare malignancy has been associated with various factors, including ultraviolet light, compromised immune function, and the presence of the Merkel cell polyomavirus (MCPyV). Despite ongoing discussions regarding the origin of the cancer cells, this tumor exhibits characteristics similar to the Merkel cells normally found in the skin, both in terms of appearance and immunohistochemical markers. This report describes a case from the Mohamed VI University Hospital Center in Marrakech, where a 79-year-old patient presented with a rapidly growing mass on their upper lip. The diagnosis of MCC relies on comprehensive pathological analysis, including immunohistochemical profiling, and it is essential to differentiate it from other malignancies to ensure proper treatment.
