Merkel cell carcinoma (MCC) is a rare and very aggressive skin cancer of the elderly. It is a primary neuroendocrine carcinoma consisting of malignant small cells typically expressing cytokeratin 20 and neuroendocrine markers. The nationwide investigation into the epidemiology of MCC in Japan presented 174 cases at the year of 1995, so that the estimated prevalence of MCC in Japan was 1.45 per million . It is known that MCC is associated with advanced age and immunosuppressive condition such as patients with renal transplant and AIDS, raising the possibility that MCC may have an infectious origin. Recently, Feng et al. identified a new human polyomavirus, which was named Merkel cell polyomavirus (MCV) and found the virus DNA in 8 of 10 (80%) MCC patients . Subsequent studies have confirmed…