User:Mr. Ibrahem/Basal-cell carcinoma

Basal-cell carcinoma (BCC), also known as basal-cell cancer, is a type of skin cancer. The classic appearance is a painless small raised bump in the skin, which may be shiny with overlying small blood vessels, and have a central dip or ulcer, crusting, or blood. Larger ones may have a rolled edge. Other patterns may include blue-grey fluid-filled small bumps, white plaques, or dry scaly marks. There are generally no symptoms; though if scratched, they may bleed. It tends to grow slowly, damage surrounding tissue, but is unlikely to spread to distant areas or result in death.

Risk factors include exposure to ultraviolet light, having lighter skin, radiation therapy, long-term exposure to arsenic and poor immune-system function. The use of tanning beds and exposure to UV light during childhood is particularly harmful. It is believed to originate from a type of cell associated with the hair follicle. Diagnosis is by its appearance and confirmed by tissue biopsy.

It remains unclear whether sunscreen affects the risk of basal-cell cancer. Treatment is typically by surgical removal. This can be by simple excision if the cancer is small; otherwise, Mohs surgery is generally recommended. Other options include electrodesiccation and curettage, cryosurgery, topical chemotherapy, photodynamic therapy, laser surgery or the use of imiquimod, a topical immune-activating medication. In the rare cases in which distant spread has occurred, chemotherapy or targeted therapy may be used.

Basal-cell cancer is the most common type of skin cancer and the most common cancer overall. It accounts for at least 32% of all cancers globally. Of skin cancers other than melanoma, about 80% are basal-cell cancers. It occurs most frequently in Australia, where 50% of people develop BCC before the age of 70. In the United States, about 35% of white males and 25% of white females are affected by BCC at some point in their lives.