Common Types of Skin Cancers

Bay Area Dermatology Associates diagnose and treat all types of skin cancer. The most common types are basal cell carcinoma, squamous cell carcinoma, and melanoma.

Basal Cell Carcinoma is the most common type of skin cancer. It originates from the basal cells of the epidermis and occurs most frequently on sun-exposed areas of the body. It can invade surrounding tissue but rarely spreads to other organs. Signs of this type of cancer are an open sore, a reddish patch, a growth with a raised edge and dimple in the center, or a bump or scar-like area.

Squamous Cell Carcinoma is the second most common form of skin cancer. It originates from the squamous cells in the epidermis and is also related to sun exposure. It can invade surrounding tissue, deeper tissues and may spread to neighboring lymph nodes. Signs include scaly red patches, raised growths with a dimple in the center, wart-like growths and open sores. All may develop a crusty surface or bleed.

Melanoma is a very serious form of skin cancer that comes from the cells of the skin that produces the pigment melanin. These tumors may appear as a dark brown, black, or multicolored growth, with irregulary shaped border that may become crusty or bleed. Rarely, it can occur as a red or flesh-toned bump. A melanoma is summarized by the ABCDE's of skin exam:

A = Asymmetry. One side of the mole does not look like the other. You cannot cut it like a pie and have two matching pieces.

B = Border Irregularity. The border is not smooth; it may have small jagged edges or a notch or look like a map of the coastline.

C = Color Variation. A benign lesion should have the same color all the way across. Colors such as black, red, white, blue, or two colors of brown in the same lesion are suspect.

D = Diameter greater than a pencil eraser. Lesions wider than 6 millimeters (a #2 pencil eraser for those of us in the United States!) are suspicious.

E = Evolution. A change in size, color, thickness or a lesion that become itchy, "burns" or bleeds is suspicious. A new mole after the age of 50 has a 25% chance of being a melanoma. Thus, we ask anyone over 40 with a new mole to come in to have it checked.