Case 182. HPV-60 infection (plantar cystic wart) (13 y-o F)
Excision of an intradermal nodule on the sole
Key words : human papillomavirus, plantar cystic wart
The cyst wall contains a few eosinophilic cytoplasmic inclusions. Round, vacuolated structure is characteristic and pathognomonic of HPV-60-related plantar cystic wart (HE, low power).   The overlying epidermis reveals marked formation of eosinophillic cytoplasmic inclusions (HE, high power). Note the difference in staining from myrmecia (case 181) .
HPV antigen is expressed in some nuclei with eosinophilic inclusions (immunostaining). The cytoplasmic inclusions are not immunoreactive.   Electron micrograph of the plantar cystic wart. The eosinophilic inclusion is filled with interlacing bundles of cytokeratin. The compressed nucleus shows clustering of virions (viral inclusion bodies).
The intranuclear viral inclusion is composed of small viral particles. Ubiquitin immunostaining was negative.