Lack of evidence for basal or squamous cell carcinoma infection with Merkel cell polyomavirus in immunocompetent patients with Merkel cell carcinoma.

Background: Merkel cell polyomavirus (MCV) was discovered by digital transcriptome subtraction as a monoclonal infection of Merkel cell carcinoma (MCC) tumors. Subsequent studies have repeatedly confirmed that MCV is the likely cause for most MCC. Polymerase chain reaction-based detection of the virus in other nonmelanoma skin cancers, however, has been inconsistent and controversial.