"A" stands for asymmetry. Growths with irregular shapes, such as two very different-looking halves, should be checked out by a doctor. 
Border Irregularity"B" stands for border irregularity. Moles with irregular, notched or scalloped borders are cause for concern, as these are all characteristics of melanoma.
Color"C" stands for color variety. Look for growths that have many colors or an uneven distribution of color.
Diameter"D" stands for diameter greater than 5 millimeters. "We all have beauty marks, but if it becomes large, you should be concerned," Dr. Jody A. Levine, a dermatologist from Plastic Surgery & Dermatology of NYC, told FOXNews.com.
Evolving "E" stands for evolving.Has the mole or skin lesion changed color, size or shape? Does it looks different than the others?
Basal CellBasal cell carcinoma is the most common form of cancer, with an estimated 1 million new cases each year in the U.S.
Basal Cell 2Basal cell carcinoma can look like a red, scaly growth on the skin, or similar to a pimple. It could bleed or look like a cut that isn’t going away.
Basal Cell 3Any mark on the skin that cannot be attributed to a specific cause should be looked at, Levine says.
Squamous Cell Squamous cell carcinoma is the second most common form of skin cancer, with over 250,000 new cases per year estimated in the United States.
Squamous Cell 2 Most cases of squamous cell carcinoma are caused by chronic overexposure to the sun.
Squamous Cell 3 Squamous cell carcinoma can metastasize if it starts on a mucous membrane such as the lips or eyes.
Source: American Academy of Dermatology, Foxnews.com