Skin basal cell carcinoma.

Basal cell carcinoma (BCC) is a low-grade malignancy of basal keratinocytes, the cells responsible for epidermis formation. Melanocytes are seen between the keratinocytes, but they are not responsible for this tumor type. The etiology is multifactorial, related to ultraviolet sun exposure, radiation, and immunosuppression, among other factors. This is one of the most common cancers in humans. The tumors will typically present in older adults, although young adults can also develop this tumor. There is a slight male predilection, but this may be due to differences in sun exposure rather than gender variance. Caucasians and light-skinned people have a higher incidence than dark-skinned people.