Types of Skin Cancer
If the biopsy indicated that you have skin cancer, it also most likely gave your doctor enough information to identify whether you have a nonmelanoma skin cancer or melanoma. The result of the biopsy will direct the treatment plan and follow up procedures.
There are three main types of skin cancer, which include:
- Squamous cell carcinoma (SCC)
- Basal cell carcinoma (BCC)
Basal cell cancer and squamous cell cancer are the two most common types of skin cancer. These cancers often form on the head, face, neck, hands, and arms; areas that are often exposed to the sun.
Melanoma is much less common than the other types but much more likely to invade nearby tissue and spread to other parts of the body. Most deaths from skin cancer are caused by melanoma.
Basal Cell Carcinoma (BCC)
BCCs are abnormal, uncontrolled growths or lesions that arise in the skin’s basal cells, which line the lowest layer of the epidermis, called the basal cell layer. It usually occurs on areas of the skin that have been exposed to the sun and often looks like open sores, red patches, shiny bumps, pink growths, or scars. This type of cancer is most commonly found on the face. BCC grows slowly, rarely spreading to other parts of the body. However, if it is left untreated, it can grow into nearby areas and invade the bone or other tissues beneath the skin.
Squamous Cell Carcinoma (SCC)
Squamous cell skin cancer is an uncontrolled growth of abnormal cells that also occurs on parts of the skin that have been exposed to the sun— primarily the upper layers (epidermis). These areas typically include the rim of the ear, lower lip, face, neck, balding scalp, hands, arms, and legs. However, places on your body that do not receive any sun exposure, including inside the mouth and on the genitals, can also be affected. SCCs often look like scaly red patches, open sores, elevated growths with a central depression, or warts. At times, these skin abnormalities may crust or bleed. Although not usually life-threatening, untreated squamous cell cancer can sometimes spread to lymph nodes and organs inside the body, causing serious complications.
If skin cancer spreads from its original place to another part of the body, the new growth has the same kind of abnormal cells and the same name as the primary growth, it is treated as skin cancer.
While melanoma is much less common than basal cell and squamous cell skin cancers, it is the most serious type of cancer of the skin and has become more common every year. In fact, in the United States alone, the percentage of people who develop melanoma has more than doubled in the past 30 years. This is because it is much more likely to spread if not caught early. The times it is recognized and treated early, however, melanoma is usually curable. If it is not caught early this type of skin cancer can advance and spread to other parts of the body, where it becomes more difficult to treat.
Melanoma starts in cells in the skin called melanocytes, which are the cells found between the dermis and epidermis. They often look like moles, and some actually start out as moles.
These cancerous growths develop when UV radiation triggers genetic defects to skin cells that lead to a rapid multiplication of skin cells that form malignant (cancerous) tumors. In most cases, melanomas are black or brown, however, some may be skin-colored, pink, red, purple, blue or white.
Melanomas can develop anywhere on the skin, but they are more likely to develop on the trunk (chest and back) in men and on the legs in women. Other common areas include the neck and face. Find out how to check your skin for signs of skin cancer.
If you notice new spots on the skin or see changes in existing ones, tell your doctor or dermatologist. Click to view some photos that can help you identify whether a mole may be melanoma. These photos are meant as a guide, but it is always best to see a doctor who can give you an exam and perform a biopsy if needed.
Lesser-Known Skin Cancers
While basal cell carcinoma, squamous cell carcinoma, and melanoma account for 99% of all skin cancer cases, there are other forms of skin cancer worth being aware of.
Merkel Cell Carcinoma (MCC)
This is a rare, aggressive skin cancer that primarily occurs on sun-exposed skin such as the head and neck, as well as the arms, legs, and trunk. MCC usually appears as a firm, pink, red, or purple lump on the skin, which is usually painless. Because MCC is a fast-growing cancer it can be hard to treat if it spreads to areas beyond the skin. Learn more about Merkel cell carcinoma from The American Cancer Society.
Kaposi Sarcoma (KS)
This type of cancer develops from the cells that line lymph or blood vessels. It can appear on the skin as a darkish/purple-colored tumor (or lesion) or on the inside of the mouth. Although lesions typically do not cause symptoms, they can spread to other parts of the body. KS is caused by the human herpesvirus-8 (HHV-8), however, not everyone infected with HHV-8 will develop this type of skin cancer. Infected people whose immune systems have been weakened by disease or by drugs given after an organ transplant are usually at a higher risk.
Types of Kaposi Sarcoma
There are a few different types of KS that are named from the populations that they are present in; however, the changes within the KS cells are all very similar. The different types of KS include:
- Classic (Mediterranean) Kaposi sarcoma
- Latrogenic (transplant-related) Kaposi sarcoma
- Endemic (African) Kaposi sarcoma
- Epidemic (AIDS-related) Kaposi sarcoma
- Kaposi sarcoma in HIV negative men who have sex with men
Epidemic (AIDS-related) Kaposi sarcoma develops in those who are HIV infected. Human immunodeficiency virus (HIV) is the virus that causes AIDS. This type is the most common type of KS in the United States. Learn more about Kaposi sarcoma from The American Cancer Society.
Lymphoma of the Skin
Lymphoma is a broad term for cancer that begins in cells of the lymphatic system— a network of tissues and organs that rid the body of toxins and waste. In addition, the lymphatic system transports infection-fighting white blood cells through the body. While lymphoma commonly involves the lymph nodes, it can begin in other lymphoid tissues such as the spleen, bone marrow, and the skin. The two main types of lymphomas are Hodgkin lymphoma and non-Hodgkin lymphoma. Lymphomas that originated only in the skin are called skin lymphoma (or cutaneous lymphoma).
In addition to some of the typical skin cancer treatments such as photodynamic therapies, chemotherapy, and targeted therapies, lymphoma of the skin may also be treated by stem cell transplants, immunotherapy treatments, and clinical trials involving lymphoma vaccines. Learn more about lymphoma of the skin from The American Cancer Society.