Massachusetts General Hospital

Basal Cell Carcinoma

What is basal cell carcinoma?

Basal cell cancer, a type of nonmelanoma skin cancer, usually appears as a small, fleshy bump or nodule on the head, neck, or hands. Occasionally, these nodules appear on the trunk of the body, usually as flat growths. Basal cell carcinoma accounts for the majority of all skin cancers in the United States. It is often easily detected and has an excellent record for successful treatment.

Nearly all basal cell carcinomas can be treated successfully, although in some cases they may recur (come back after treatment). Although this type of cancer rarely spreads to other parts of the body, it can extend below the skin to the bone and cause considerable local damage if not treated. And, having a basal cell carcinoma places people at high risk for developing additional skin cancers.

Who is at risk for basal cell carcinoma?

Basal cell carcinoma is the most common skin cancer found in whites and is much less common in people with dark skin. People who have this cancer frequently have light hair, eyes, and complexions, and they do not tan easily. Other risk factors for basal cell carcinoma include:

• Excess exposure to UV radiation (sunlight or tanning beds)

• Older age

• Male gender

• Exposure to certain chemicals

• Radiation exposure

• Long-term skin inflammation or injury

• Treatment for psoriasis using psoralens and ultraviolet light treatments  

• History of skin cancer

• Basal cell nevus (Gorlin) syndrome (a rare inherited disorder) 

How does basal cell carcinoma develop?

This highly treatable cancer starts in the basal cell layer of the epidermis (the top layer of skin) and grows very slowly. A basal cell carcinoma usually appears as a small, shiny bump or nodule on the skin, and mainly on the areas exposed to the sun, such as the head, neck, arms, hands, and face.