Merkel Cell Virus

We can now conclude that all Merkel cell carcinomas are caused by viral infection, likely associated with a compromised immune system.

Merkel cell carcinomas (MCCs) occur more often in immunocompromised patients than in others. Many MCCs harbor a viral genome for Merkel cell polyomavirus (MCPyV) in tumor DNA, presumably as a consequence of infection by MCPyV itself. MCPyV DNA clonally integrates into the tumor and produces mutations and deletions of critical genes governing the large T antigen of MCPyV. Several study groups have detected either MCPyV DNA (by polymerase chain reaction [PCR]) or large T antigen, or both, in about 80% of formalin-fixed, paraffin-embedded MCC tissue samples (see JW Dermatol Jun 17 2011). Are the remaining 20% of tumors also caused by undetected MCPyV or by some nonviral cause?

Investigators recently attempted to increase the sensitivity of dete…

Reviewing Author

Mark V. Dahl, MD

Disclosures

Consultant / Advisory board Ulthera, Inc.; AuBio LifeSciences, LLC; Paris Therapeutics

Equity Elorac, Inc.; Makucell, Inc.; Paris Therapeutics

Editorial boards UpToDate

Leadership positions in professional societiesNational Rosacea Society (Chairman, Medical Board)