<unk> <unk>  carcinoma is the second-most common<unk>  of the<unk>  (after basal-cell carcinoma but more common than melanoma). It usually occurs in areas exposed to the sun. Sunlight exposure and immunosuppression are risk factors for SCC of the<unk> , with chronic sun exposure being the strongest environmental risk factor. There is a risk of metastasis starting more than 10 years after diagnosable appearance of<unk> <unk>  carcinoma, but the risk is low, though much higher than with basal-cell carcinoma.<unk> <unk><unk> s of the lip and ears have high rates of local recurrence and distant metastasis. In a recent study, it has also been shown that the deletion or severe down-regulation of a gene titled Tpl2 (tumor progression locus 2) may be involved in the progression of normal keratinocytes into becoming<unk> <unk>  carcinoma. SCCs represent about 20% of the non-melanoma<unk><unk> s, but 80-90% of those with metastatic potential are located on the head and neck. Tobacco smoking is also increases the risk for cutaneous<unk> <unk>  carcinoma. The vast majority of SCCs are those of the<unk> , and are often the result of ultraviolet exposure. SCCs usually occur on portions of the body commonly exposed to the Sun; the face, ears, neck, hands, or arm. The main symptom is a growing bump that may have a rough, scaly surface and flat reddish patches. Unlike basal-cell carcinomas, SCCs carry a higher risk of metastasis, and may spread to the regional lymph nodes, Erythroplasia of Queyrat (SCC in situ of the glans or prepuce in males, M or the vulvae in females.) may be induced by human papilloma virus. It is reported to occur in the corneoscleral limbus. Erythroplasia of Queyrat may also occur on the anal mucosa or the oral mucosa. Some sources state that this condition is synonymous with Bowen's disease, however generally speaking Bowen's disease refers to carcinoma in situ of any location on the<unk>  such as the lower leg. Genetically, SCC tumors harbor high frequencies of NOTCH and p53 mutations as well as less frequent alterations in histone acetyltransferase EP300, subunit of the SWI/SNF chromatin remodeling complex PBRM1, DNA-repair deubiquitinase USP28, and NFKB signaling regulator CHUK . Immunosuppression People who have received solid organ transplants are at a significantly increased risk of developing<unk> <unk>  carcinoma due to the use of chronic immunosuppressive medication. While the risk of developing all<unk><unk> s increases with these medications, this effect is particularly severe for SCC, with hazard ratios as high as 250 being reported, versus 40 for basal<unk>  carcinoma. The incidence of SCC development increases with time posttransplant. Heart and lung transplant recipients are at the highest risk of developing SCC due to more intensive immunosuppressive medications used.<unk> <unk><unk> s of the<unk>  in individuals on immunotherapy or suffering from lymphoproliferative disorders (i.e. leukemia) tend to be much more aggressive, regardless of their location. The risk of SCC, and non-melanoma<unk><unk> s generally, varies with the immunosuppressive drug regimen chosen. The risk is greatest with calcineurin inhibitors like cyclosporine and tacrolimus, and least with mTOR inhibitors, such as sirolimus and everolimus. The antimetabolites azathioprine and mycophenolic acid have an intermediate risk profile.
Squamous cell skin cancer
Basal-cell carcinoma
Melanoma
Mucosal melanoma
Wart
Animal-type melanoma
Actinic keratosis
Skin cancer