Case 180. Reference case 180B

　 　 　 　
　 Electron micrograph of verruca vulgaris, showing small-sized 40 nm viral particles in the nuclear matrix. HPV antigen was undetectable in this case. 　
　 　 　 　

　

 　 EM features are consistent with production of viral virions, while immunostaining using HPV antiserum failed to identify positive signals.