Slightly raised wart 2-5 mm in diameter often associated with viral infections, commonly persistent in immunodeficient individuals.

Squamous cell carcinoma of the skin is a malignant tumor of squamous epithelium.

Human papillomaviruses (HPVs) are small oncogenic viruses. HPV has been shown to cause a variety of lesions and malignancies, which predominantly affect the anogenital region. Low-risk, non-oncogenic HPV types are associated with anogenital warts and recurrent respiratory papillomatosis while high-risk, oncogenic types are associated with cervical, penile, anal, vaginal, vulvar, and oropharyngeal cancers. Infection with anogenital HPV is usually asymptomatic and resolves spontaneously without consequences in the immunocompetent host. When disease does occur, the most common manifestation is genital warts, which may be small papules, or flat, smooth or pedunculated lesions. This resolution of HPV lesions is not generally seen in the immunosuppressed, resulting in severe, persistent and extensive manifestations of HPV disease.