Skin Cancer
Common Types
Basal Cell Carcinoma
This tumor of the skin usually appears as a non-healing area, blemish that 
won’t heal, enlarging red patch, or bump on the skin. The frequency of basal cell carcinomas increases in lighter skinned individuals and with increased sun exposure. Although more uncommon, these can occur in darker skinned people.
These tumors don't spread quickly. It may take many months or years for one to reach a diameter of one half inch. Untreated, the cancer will begin to bleed, crust over, and repeat the cycle.
Although this type of cancer generally does not metastasize (spread to other parts of the body), it can extend below the skin to the bone and cause considerable local damage.
Squamous Cell Carcinoma
These tumors may appear as nodules or as red, scaly patches. Squamous Cell is the second most common skin cancer found in Caucasians. It 
typically is found on sun-exposed areas and unlike basal cell carcinomas can grow very quickly. It is rarely found on dark-skinned individuals. This cancer frequently will increase in size, developing in time into a relatively large tumor. Unlike Basal cell carcinoma, it can metastasize.
The cure rate for both basal cell and squamous cell carcinoma is very high, when properly treated. Early detection greatly improves cure rate, cosmetic end result after treatment, and occasionally risk of metastasis.
Malignant Melanoma
Melanoma has its beginnings in melanocytes, the skin cells which produce the dark protective pigment called melanin. It is melanin which is responsible for suntanned skin acting as a partial protection against the sun. Melanoma cells usually continue to produce melanin, which accounts for the cancers appearing in mixed shades of tan, brown and black. Melanoma has a tendency to spread, making it essential to treat.
Melanoma may suddenly appear without warning but it may also begin in or near a mole or other dark spot in the skin. For that reason it is important that we know the location and appearance of the moles on our bodies so any change will be noticed.
Increased exposure to he sun, especially when younger, is thought to increase the risk of developing malignant melanoma. Heredity may play a part especially in individuals where increased numbers of normal moles or atypical (dysplastic) moles run in their family. These act as a marker for the development of a melanoma either within a preexisting mole or on normal skin. This can occur in either sun exposed areas or sun protected areas
Dark brown or black skin is not a guarantee against melanoma. Dark skinned people can develop this cancer, especially on hands or feet.
The ABCDs of Melanoma - Signs to Look For
- Asymmetry
One half doesn't match the other half. - Border irregularity
The edges are ragged, notched or blurred.
- Color
The pigmentation is not uniform. Shades of tan brown and black are present.
- Diameter
Greater than six millimeters (about the size of a pencil eraser). Any growth in size of a mole should be of concern.
Some additional warning signs of melanoma would include: changes in the surface of a mole; scaliness, oozing, bleeding or the appearance of a bump or nodule; spread of pigment from the border into surrounding skin; and change in sensation including itchiness, tenderness, or pain.
Melanoma, like its less aggressive cousins, basal cell and squamous cell carcinomas, is frequently entirely curable in its early stages.
Prevention
Prevention is a matter of sun protective measures (protective clothing and sunscreens) and self examination (for early detection).
If any growth, mole, sore or discoloration appears suddenly or begins to change, please have it checked by your primary care provider or a dermatologist at your earliest convenience.
Fortunately, skin cancers are relatively easy to detect and most can be cured. Even malignant melanoma, if caught in its early stages, can be treated successfully.
Treatment
Early detection is the surest way to a cure. It is a simple routine to inspect your body for any skin changes - particularly anything resembling the illustrations on the Skin Cancer information page.
If any growth, mole, sore or discoloration appears suddenly or begins to change, please have it checked by your primary care provider or a dermatologist at your earliest convenience. It is very important to identify skin cancers early! Fortunately, skin cancers are relatively easy to detect and most can be cured. Even malignant melanoma, if caught in its early stages, can be treated successfully.
Very rarely, a cancer will grow back. In order to detect this rare event, the treated area should be checked periodically. If you become concerned about the treated area or if other skin growths appear, please be evaluated.