Squamous cell carcinoma | |
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Synonyms | epidermoid carcinoma, squamous cell epithelioma |
SCC of the skin tends to arise from pre-malignant lesions, actinic keratoses; surface is usually scaly and often ulcerates (as shown here). | |
Classification and external resources | |
Specialty | Dermatology, plastic surgery, otorhinolaryngology |
ICD-10 | C44 |
ICD-9-CM | 199 |
ICD-O | M8070/3 |
MedlinePlus | 000829 |
eMedicine | derm/401 |
MeSH | D002294 |
Squamous cell carcinoma (SCC or SqCC), also known as squamous cell cancer, is cancer that begins from squamous cells, a type of skin cell. It is one of the main types of skin cancer. Cancers that involve the anus, cervix, head and neck, and vagina are also most often squamous cell cancers. The esophagus, urinary bladder, prostate, and lung are other possible sites.
Frequent exposure to direct, strong sunlight without adequate topical protection also increases risk. Despite sharing the name squamous cell carcinoma, the SCCs of different body sites can show differences in their presenting symptoms, natural history, prognosis, and response to treatment.
SCC typically initially occurs in the sixth decade of life (the 50s), but is most common in the eighth decade (the 70s). It is twice as common in men as in women. People with darker skin have a lower risk than individuals with lighter colored skin. Populations with fair skin, light hair and eyes are at highest risk of developing the disease.
Symptoms are highly variable depending on the involved organs.
SCC of the skin begins as a small nodule and as it enlarges the center becomes necrotic and sloughs and the nodule turns into an ulcer.
About one-third of lingual and mucosal tumors metastasize before diagnosis (these are often related to tobacco and alcohol use).
Human papilloma virus (HPV) has been associated with SCC of the oropharynx, lung, fingers, and anogenital region.
Squamous cell carcinoma is the second-most common cancer of the skin (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 skin, 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 squamous cell carcinoma, but the risk is low, though much higher than with basal-cell carcinoma. Squamous cell cancers of the lip and ears have high rates of local recurrence and distant metastasis (20–50%). 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 squamous cell carcinoma.