Merkel cell carcinoma: banal-appearing, aggressive actor.

Merkel cell carcinoma is a rare but often deadly cutaneous malignancy. It carries a 40 percent five-year mortality rate, in contrast to 15 percent for malignant melanoma, and the incidence is increasing among older and immunosuppressed patients. Dermatologists need to be aware of the particular diagnostic and treatment challenges as the incidence increases. New data is helping to identify patients most at risk, accurately stage the tumor and to optimize treatment regimens. With the recent discovery of a virus as part of the etiology of this tumor, approaches to use the body's immune system to attack the tumor have potential to significantly increase survival rates in the future. Merkel Cell carcinoma (MCC) is a rare but aggressive cutaneous malignancy. Its aggressive behavior, combined with its asymptomatic clinical presentation, means that tumors are often allowed to grow and spread before detection. As the tumor becomes better characterized and its etiology better understood, research is rapidly advancing in both pathogenesis and treatment. Since the discovery of a viral etiology for this tumor in 2008, progress is advancing rapidly.