What is skin cancer?
Some types of skin cancer are potentially more dangerous than others.
Skin cancer is the abnormal and uncontrolled growth of skin cells. Skin cancer usually arises on skin exposed to the sun, such as the face, lips, ears, scalp, neck, chest, arms and hands and on the legs, especially in women. Though more common in people who have lighter skin tones, skin cancer affects people with all skin tones. There are three major types of skin cancer
Each type of skin cancer has a different pathology and presentation.
Does skin cancer kill you?
Malignant melanoma is a highly aggressive skin cancer that tends to spread to other parts of the body. All other types of skin cancers have the potential to be locally invasive and spread to other parts of the body. Nonmelanoma skin cancers are comparatively less aggressive. Self-examination of the skin for suspicious changes, changes in existing moles, persistent inflammation, ulcers, etc. can help detect skin cancer at its earliest stages. Early detection of skin cancer gives the patient the greatest chance of having successful skin cancer treatment.
What are the types of skin cancer?
The main types of skin cancers are
Basal cell carcinoma usually occurs in sun-exposed areas of the body, such as the face, lips or neck. Basal cell carcinoma may present as
- A pearly or waxy bump
- A flat, flesh or brownish scar-like lesion
- An ulcer that bleeds and has crusting
- An ulcer heals and recurs quickly
Squamous cell carcinoma usually arises in sun-exposed areas of the body, such as the face, ears, hands or legs. People with darker skin tones may develop squamous cell carcinoma on areas that are not exposed to the sun. Squamous cell carcinoma presents as
- A firm, red nodule
- A flat lesion that may be scaly or crusty
Melanoma can develop anywhere on the body. It may arise from an existing mole that becomes cancerous or from normal skin cells. Melanoma tends to occur on the face or the trunk in men. In women, it tends to occur on the legs. Melanoma can occur on areas not exposed to the sun. Melanoma can affect people of all skin tones but it is more common in people who have lighter skin tones. Melanoma presents as
- A large brownish spot with darker speckles
- A mole that changes in color, size or feel or bleeds
- A large brownish patch or spot
- A small lesion with an irregular border with areas that appear red, pink, white, blue or blue-black
- Pain, itching or burning of the lesions
Rare types of skin cancers
Other rare types of skin cancer that may occur are
- Kaposi sarcoma: This is caused by the herpes simplex virus 8 (HSV-8) and is usually seen in people who have diseases associated with a weak immune system like AIDS. It arises from the blood vessels in the skin. The lesions appear as red or reddish-brown or purple patches on the skin or mucous membranes.
- Merkel cell carcinoma: This presents with firm, shiny nodules that occur on or just beneath the skin and hair follicles. The lesions commonly occur on the head, neck and trunk.
- Sebaceous gland carcinoma: This is a rare and aggressive cancer that originates in the sebaceous glands (oil glands) in the skin. It presents as hard, painless nodules that can occur anywhere, but commonly appear on the eyelids and may be misdiagnosed as other eyelid problems.
Self-examination is important in the detection of skin cancer.
What causes skin cancer?
Various factors that may increase the risk of skin cancer include
- Lighter skin tones
- History of sunburns in the past
- Excessive sun exposure
- Several moles
- Precancerous skin lesions
- Family history
- History of skin cancer
- Weak immune system
- Exposure to radiation
- Exposure to toxins
How is skin cancer treated?
The treatment depends on the type and extent of skin cancer. Treatment options include
- Cryosurgery: Destroying small precancerous lesions and early-stage cancer by freezing with a liquid nitrogen gun.
- Excisional surgery: Surgical excision (cutting out) of the cancerous tissue along with a surrounding margin of healthy skin.
- Mohs surgery: This procedure is performed for large, invasive and recurring skin cancer. The lesion is surgically removed layer by layer, and each layer is analyzed under the microscope until no abnormal cells are found. This procedure prevents excessive removal of surrounding healthy skin.
- Curettage: After the majority of the cancerous growth is removed, the remaining layers of cancer cells are scraped away using a sharp device called a curet.
- Radiation therapy: Radiation therapy uses external radiation beams to destroy cancer cells.
- Chemotherapy: Anticancer drugs are used to kill cancer cells.
- Photodynamic therapy: This treatment destroys skin cancer cells using a combination of laser light and medication that makes cancer cells sensitive to light and hence destroys them.
- Biological therapy: Biological therapy modulates the immune system to kill cancer cells.