More about Skin Cancer
Skin cancer is a common, usually low-grade cancerous (malignant) growth of the skin. It starts from cells that begin as normal skin cells and transform into those with the potential to reproduce in an out-of-control manner. Unlike other cancers, the vast majority of skin cancers have no potential to spread to other parts of the body (metastasize) and become life-threatening.
- There are two major types of skin cancer: basal cell carcinoma (the most common) and squamous cell carcinoma (the second most common). Melanoma is also a form of skin cancer but is far less common, though more dangerous, than the other two varieties.
- The exact cause of skin cancer is unknown. It appears basal cell skin cancers arise from basaloid cells in the upper layer of the skin. Uncontrolled growth of these cells is regulated by other factors in the skin. When that regulation is lost, skin cancer cells begin to grow into tumors.
- In squamous cell skin cancers, the tumors arise from a normal cell in the top layer of the skin, the epidermis. As with basal cell cancers, these cells are prevented from growing wildly by genetically controlled factors. When there is an alteration in the genes that regulate these cells, the control is lost and skin cancers start to grow. In many instances, the genes are altered by sunlight exposure.
What are the signs and symptoms of skin cancer?
Most basal cell carcinomas have few if any signs or symptoms. Squamous cell carcinomas may be painful. Both forms of skin cancer may appear as a sore that bleeds, oozes, crusts, or otherwise will not heal. There is often a slowly growing bump on the skin that may bleed after minor trauma. Both kinds of skin cancers may have raised edges and a central ulceration.
Signs and symptoms of basal cell carcinomas include:
- Appearance of a shiny pink, red, pearly, or translucent bump
- Pink skin growths or lesions with raised borders that are crusted in the center
- Raised reddish patch of skin that may crust or itch, but is usually not painful
- A white, yellow, or waxy area with a poorly defined border that may resemble a scar
Signs and symptoms of squamous cell carcinomas include:
- Persistent, scaly red patches with irregular borders that may bleed easily
- Open sore that does not go away for weeks
- A raised growth with a rough surface that is indented in the middle
- A wart-like growth
Actinic keratoses (AK), also called solar keratosis are scaly, crusty lesions caused by damage from ultraviolet light, often in the facial area, scalp, and hands. In some cases these are considered potential precancers. If untreated, up to 10% of actinic keratosis growths can develop into squamous cell carcinoma, and in rare cases some can turn into basal cell carcinomas.