This page was reviewed under our medical and editorial policy by
Maurie Markman, MD, President, Medicine & Science
This page was updated on June 1, 2022.
Because many skin cancers develop where they can be seen, there is a good chance of catching them early. Regular examination of the skin for any new or unusual growths, or changes in existing moles is critical.
Patients who find anything suspicious should discuss it with a primary care physician, a dermatologist (skin doctor) or a health care professional who is qualified to diagnose skin cancer.
A variety of skin changes may indicate skin cancer or precancerous conditions.
In addition to looking for the specific signs below, also be on the lookout for the following mole irregularities (using what's known as the ABCDE system), which may indicate skin cancer.
| Asymmetry | One side of a mole is distinctly different from the other side. |
| Borders that are irregular | A mole or lesion has edges that aren’t even, such as being notched, blurred or ragged. |
| Color that’s uneven | Moles may have a variety of colors, including brown, black, tan, white, gray, pink or even blue. |
| Diameter | Moles have changed in size or are bigger than the size of a pea. |
| Evolving | Moles have changed in size, shape or color in the recent past. |
Common skin cancer symptoms may include:
An unusual skin growth or sore that doesn't go away may be the first indication of a non-melanoma skin cancer. Skin cancer may initially appear as a nodule, rash or irregular patch on the surface of the skin. These spots may be raised and may ooze or bleed easily. As the cancer grows, the size or shape of the visible skin mass may change and the cancer may grow into deeper layers of the skin.
Even if a dermatologist has already examined a mole or lesion and said it's not cancerous, it's important to continue monitoring these skin irregularities. Any changes in the shape, color or size of existing spots should be examined by a health care professional.
Basal cell carcinomas on the head or neck may first appear as a pale patch of skin or a waxy translucent bump. The patient may see blood vessels or an indentation in the center of the bump. If the carcinoma develops on the chest, it may look more like a brownish scar or flesh-colored lesion. As the cancer develops, it may bleed if injured or ooze and become crusty in some areas.
Squamous cell carcinomas may also develop as a lump on the skin. These firm lumps are typically rough on the surface, unlike the smooth and pearly appearance of a basal cell carcinoma. If a nodule doesn't form, the cancer may develop more like a reddish, scaly patch. Unlike a skin rash that goes away with time, these rough, lesion-like patches continue to develop slowly. This type of cancer is typically found on the head, neck, hands or arms, but they may also develop in other areas, such as the genital region or in scars or skin sores.
Merkel cell carcinomas may appear as red or flesh-colored moles that are raised and grow quickly. These small tumors usually appear on sun-exposed areas of the skin, such as the face, neck or scalp.
Regular examination of the skin for any new or unusual growths, or changes in the size, shape or color of an existing spot, is key to finding and treating skin cancers early. Discuss anything suspicious with a primary care physician or a dermatologist.
While many skin cancers develop in areas exposed to the sun, they may also develop in areas that are usually hidden from the sun. It is important to examine all of these areas. In addition to examining the legs, trunk, arms, face and neck, look for signs of skin cancer in the areas between the toes, underneath nails, palms of the hands and soles of the feet, genitals and even the eyes.
Next topic: What are the types of skin cancer?