Fig. 2

Photomicrographs of a representative example of the presence of HPyV6 detected by FISH in a keratoacanthoma: a DNA sequence nuclear hybridization signals in the keratinocytes of the lesion (red), located mainly in the middle and upper epidermis (scale bar 30 μm). b HE staining of keratoacanthoma used for HPyV6 FISH. c DNA sequence nuclear hybridization signals with dot-like specific positivity in the keratin layer of the lesion (red) (scale bar 30 μm). d overlay DAPI staining of nuclei of keratinocytes (blue) of the area of the lesion shown in C, showing no nuclei in the keratin layer with the positive FISH signals