Non melanoma skin cancer includes 2 main types:
- basal cell skin cancer - also called basal cell carcinoma (BCC)
- squamous cell skin cancer - also called squamous cell carcinoma (SCC)
They're named after the types of skin cells where the cancer develops. It's possible for a non melanoma skin cancer to be a mixture of both these types.
Non melanoma skin cancer is different from melanoma. Melanoma is the type of skin cancer that often develops from a mole. This can be a mole that is already on your skin or a new mole or lesion that has recently appeared.
Basal cell skin cancer
BCC is the most common type of skin cancer. About 75 out of every 100 non melanoma skin cancers (75%) are BCCs. They develop from basal cells and these are found in the deepest part of the outer layer of the skin (the epidermis).
They develop mostly in areas of skin exposed to the sun, including parts of the face such as the nose, forehead and cheeks. Also, on your back or lower legs.
They are most often diagnosed in people who are middle aged or older.
Doctors might also call a basal cell cancer a rodent ulcer.
There are a number of different types of BCC. Each type can look and behave differently. They include:
- nodular basal cell skin cancer
- superficial basal cell skin cancer
- morphoeic basal cell skin cancer - also known as sclerosing or infiltrating basal cell skin cancer
- pigmented basal cell skin cancer
Nodular basal cell cancer is the most common subtype.
It's very rare for basal cell skin cancer to spread to another part of the body to form a secondary cancer. It's possible to have more than one basal cell cancer at any one time and having had one does increase your risk of getting another.
Squamous cell skin cancer
SCC is generally faster growing than basal cell cancers. About 20 out of every 100 skin cancers (20%) are SCCs. They begin in cells called keratinocytes, which are found in the epidermis.
Most SCCs develop on areas of skin exposed to the sun. These areas include parts of the head, neck, and on the back of your hands and forearms. They can also develop on scars, areas of skin that have been burnt in the past, or that have been ulcerated for a long time.
SCCs don't often spread. If they do, it's most often to the deeper layers of the skin. They can spread to nearby lymph nodes and other parts of the body, but this is unusual.
Rarer types of non melanoma skin cancer
There are other less common types of skin cancer. These include:
- Merkel cell carcinoma
- Kaposi’s sarcoma
- T cell lymphoma of the skin
- Sebaceous gland cancer
These are all treated differently from basal cell and squamous cell skin cancers.
Merkel cell carcinoma
Merkel cell carcinoma is very rare. Treatment is with surgery or radiotherapy, or both. This usually works well, but sometimes the cancer can come back in the same place. And sometimes it spreads to nearby lymph nodes or to other parts of the body.
Sebaceous gland cancer
Sebaceous gland cancer is another rare type of skin cancer affecting the glands that produce the skin's natural oils. Treatment is usually surgery for this type of cancer.
Kaposi’s sarcoma is a rare condition. It's often associated with HIV but also occurs in people who don't have HIV. It's a cancer that starts in the cells that form the lining of lymph nodes and the lining of blood vessels in the skin. Treatment is surgery or radiotherapy, and sometimes chemotherapy.
T cell lymphoma of the skin
T cell lymphoma of the skin can also be called primary cutaneous lymphoma. It's a type of non Hodgkin lymphoma. There are a number of different types of treatment for this type of cancer.
Bowen’s disease is a very early form of non melanoma skin cancer that's slow growing. It can appear anywhere on the skin and usually looks like a small red scaly patch that might be itchy.
It's most commonly found on skin exposed to the sun such as the head and neck area. Women tend to be affected more than men on the lower parts of the leg.
It can also develop on moist membranes of the body such as the mouth and genital area.
If not treated Bowen's disease might develop into squamous cell skin cancer.