In general, human papillomavirus (HPV) infections are considered benign. However, HPV subtypes 16, 18 and several others have oncogenic potential and have been shown to be associated with malignant transformation. (51) Neoplastic transformation to squamous cell carcinoma can occur  in association with HPV infection of the skin, oral mucosa cervix, vulva, penis and anogenital mucosa. Precursor lesions to HPV-associated squamous carcinoma of the cervix, vulva, penis and anus are termed high-grade squamous intraepithelial lesions (HSIL). Previous terminology such as anal intraepithelial neoplasia (AIN) are no longer routinely used. (52)  

Clinical presentation 

Infection of the skin by low-risk HPV genotypes results in development of verrucae, or ‘warts’. Clinical features vary by anatomic site, and may vary from flat papules (typically on the face or dorsal hands), clustered papules (usually on plantar surfaces) or filiform lesions (frequently on the scalp or beard area). (53) Although warts may be larger or more numerous in PLWHIV, most commonly the warts look like those found in the general population. While most cases are asymptomatic, some patients may experience pruritus, mild burning or bleeding. (54) 

In the anogenital areas however, it can be more difficult with both common genital warts (condyloma accuminatum, usually secondary to low-risk HPV types 6 and 11) as well as other lesions due to other HPV subtypes. (55, 56) For example, Bowenoid papulosis is a HPV-associated papular eruption typically involving the penis or vulva which clinically mimics genital warts but histologically resembles HSIL and is caused by high-risk genotypes (including 16, 18, 31 and 33). (57)  Penile, anal or vulval HSIL, due to high-risk HPV subtypes, otherwise often presents as erythematous lesions which may be associated with pain, bleeding or pruritus. (58) These may be difficult to different from invasive carcinoma of these anatomical sites, which can develop from HSIL precursors, and thus features including rapid growth or ulceration should raise clinical suspicion.  (52)