Polymerase chain reaction, immunohistochemistry, and viral copy number per haploid human genome of MCPyV-positive skin tumors.

<p>IHC, immunohistochemistry; MCC, Merkel cell carcinoma; BCC, Basal cell carcinoma; AK, Actinic keratosis; MLNM, Multiple lymph node metastases; ST, small T; LT, large T; CN, copy number, Tumor ratio: 1, <10%; 2, >10% and <30%; 3, >30% and <70%; 4, >70%.