Second most common skin cancer
Higher rates of metastasis than basal<unk>  carcinoma
UV radiation
Chronic arsenic exposure
Ionizing radiation
Immunosuppression
Chronic skin inflammation
Squamous cell carcinoma
Basal cell carcinoma
Kaposi's sarcoma
Melanoma
Juvenile nasopharyngeal angiofibroma
Seborrheic keratosis
Eumycetoma
Bullosis diabeticorum