Merkel cell carcinoma: If no breslow, then what?

Merkel cell carcinoma (MCC) is a skin tumor of neuroendocrine origin with a mortality of 33%, the highest of any cutaneous malignancy. Within the United States the estimated annual incidence is increasing and is estimated at 0.44 per 100,000 persons, resulting in roughly 1,000 new cases per year [1]. Several factors may be contributing to this trend, including changes in the major risk factors for this disease: the increasing age of the general population, higher rates of immunosuppression, and increasing sun exposure. Additional likely contributors to the trend include improved detection and reporting.Whilereported rates havetripled between 1986 and 2001, MCC remains approximately 50-fold less common than melanoma [1]. This rarity has hampered our ability to study this disease systematically. To date there are no controlled trials to assess treatment and outcome. Further obscuring matters is the lack of uniform agreement on staging and treatment. While its high mortality and increasing incidence have brought greater attention to MCC recently, our ability to accurately predict prognosis based on histology remains