Nonmelanoma skin cancer is the most common form of skin cancer. There are about 1.3 million cases each year in the United States. Basal cell carcinoma (80%) and squamous cell carcinoma (16%) are the most common forms of nonmelanoma skin cancers, accounting for about 96% of all new cases of skin cancer.
Other nonmelanoma skin cancers account for less than 1% of nonmelanoma skin cancers, according to American Cancer Society. These less common skin cancers include:
- Kaposi's sarcoma, which usually starts within the deeper layers of the skin but can also form in internal organs. The tumors consist of bluish-red or purple lesions. This cancer occurs in people with compromised immune systems such as those with HIV infection or AIDS as well as transplant recipients who are on immune-suppressing drugs.
- cutaneous lymphoma, a type of lymphoma that begins in the skin.
- skin adnexal tumors, rare tumors that start in the hair follicles or sweat glands, and are usually benign.
- sarcomas, which usually start in tissues deep beneath the skin, but can develop in the skin as well.
- Merkel cell carcinoma, a rare cancer of neuroendocrine origin that develops on or just beneath the skin and in hair follicles. These cancers usually appear as firm, reddish/purple shiny skin lumps.
