Non-melanoma skin cancers commonly contain Human Papillomavirus (HPV), but the types found have varied depending on the polymerase chain reaction (PCR) primer systems used. Whole genome amplified DNA (not amplified by any specific PCR primers) from 91 skin lesions [41 squamous cell skin carcinomas (SCCs), 8 keratoacanthomas, 22 actinic keratoses, 3 basal cell carcinomas and 17 SCCs in situ] were sequenced. All samples were sequenced both at 160 Mb and 1.8 Gb sequencing depth per sample. The sequences from 10 different HPVs in 47/91 specimens were found. Sequences represented four established HPV types (HPV types 16, 22, 120, 124), two previously known putative types (present in GenBank) and four previously unknown HPV sequences (new putative types). The most commonly detected virus was cloned, sequenced and designated as HPV197. Type-specific real-time PCR detected HPV197 in 34/91 specimens. For comparison, a pool of the same samples after general primer PCR amplification was also sequenced. This revealed 40 different HPVs, but only two HPV types were detected both with sequencing without prior PCR and with sequencing PCR amplicons, suggesting that sequencing without prior PCR gives a more unbiased representation of the HPVs present. In summary, it was found that HPV can be sequenced from most skin disease specimens and HPV197 appeared to be the most commonly present virus.

To assess presence of virus DNA in skin lesions, swab samples from 82 squamous cell carcinomas of the skin (SCCs), 60 actinic keratoses (AKs), paraffin-embedded biopsies from 28 SCCs and 72 kerathoacanthomas (KAs) and fresh-frozen biopsies from 92 KAs, 85 SCCs and 92 AKs were analyzed by high throughput sequencing (HTS) using 454 or Ion Torrent technology. We found total of 4,284 viral reads, out of which 4,168 were Human Papillomavirus (HPV)-related, belonging to 15 known (HPV8, HPV12, HPV20, HPV36, HPV38, HPV45, HPV57, HPV59, HPV104, HPV105, HPV107, HPV109, HPV124, HPV138, HPV147), four previously described putative (HPV 915 F 06 007 FD1, FA73, FA101, SE42) and two putatively new HPV types (SE46, SE47). SE42 was cloned, sequenced, designated as HPV155 and found to have 76% similarity to the most closely related known HPV type. In conclusion, an unbiased approach for viral DNA detection in skin tumors has found that, although some new putative HPVs were found, known HPV types constituted most of the viral DNA.

A large spectrum of HPV types from Betapapillomavirus and Gammapapillomavirus have tropism for the nasal mucosa. The implication of the relatively high prevalence of these viruses in the nasal mucosa is unknown.

Condylomas are caused by human papillomavirus (HPV), but may in rare cases be "negative for HPV" by PCR. Metagenomic sequencing can be used for an unbiased assessment of the presence of virus. Ten swab sample pools, each containing four cases of "HPV-negative" condylomas, were subjected to metagenomic sequencing. One pool contained Molluscum contagiosum. Five pools contained HPV, of which three pools contained novel putative HPV-types. The 12 samples in these three pools were sequenced individually. Six of these contained HPV and two contained Molluscum contagiosum. Altogether, 1337 HPV-related reads were detected, representing 23 novel putative Gammapapillomaviruses, 10 established HPV types (genital HPV types 6, 57, 58 and 66, Betapapillomavirus types 5, 105, 124, and Gammapapillomavirus types 50, 130, 150) and two described HPV sequences (KC7 and FA69). Complete genomes of Gammapillomavirus FA69 and SE87 were compiled. Metagenomic sequencing reveals that seemingly "HPV-negative" condylomas contain known and previously unknown HPV types.