Signs of skin cancer

Skin cancer, like all other types of cancer, has its warning signs. These signs are skin changes which do not necessary imply that a person has skin cancer, but they could turn into cancer over time. On average, between 40 and 50 percent of Caucasian adults develop at least one pre-cancerous skin change by the age of 65. Skin cancer can be cured if detected on time.

Who is most susceptible to skin cancer?

Sun exposure is the most common cause of skin cancer. However, skin cancer can also appear in areas of the body that are not exposed to sunlight. Exposure to radiation, genetic predisposition or a weakened immunity due to some other malignant illness can also cause cancer. Anyone can get skin cancer, but most susceptible categories of the population are:

  • Persons with a fair complexion with light eyes
  • Persons with a large number on moles on their body
  • Persons with a hereditary factor
  • Persons living in high altitudes
  • Persons being treated for radiation exposure
  • Persons who have had much exposure to the sun or to artificial sources of UVA radiation

Pre-cancerous skin changes

Solar keratosis (actinic keratosis)

These are red marks which appear after a high level of sun exposure. They are most common on the scalp, neck and hands. However, they can also appear on other areas of the body. These are the first signs of skin cancer. Actinic keratosis most often affects persons in their 40-ies, but it has recently been noted to present in the younger population as well. Persons with a fair complexion – along with red hair, light or blond hair, blue or green eyes – are most at risk.

Actinic cheilitis (Farmer’s lip)

Similar to actinic keratosis, actinic cheilitis is a pre-cancerous condition which usually affects the lower lip. Symptoms include red spots and flaking skin or constantly dry and chapped lips. Lip swelling and blurring of the demarcation between the lips and the surrounding skin is less common. If not timely treated, actinic cheilitis can transform into invasive carcinoma.

Cutaneous horns

Cutaneous horns are conical projections above the skin surface composed of keratin (a component of epithelial cells) which can vary in shape and size, but usually have a diameter of several millimeters. This type of skin growth is more common in adults who have a history of frequent and long sun exposure. Pre-cancerous changes or skin cancer might be detected in the base of the skin growth.

When is a mole considered problematic?

Moles are benign skin growths which can always transform into cancer; they can become atypical and transform into melanoma. Normal moles can be level with the skin surface or they can be slightly raised without posing any danger. They can grow in size over time. Moles often begin to appear in children and young adults, they are less likely to develop at an older age.

Mole self-assessment

All moles differ in size, shape and color, but some of them can develop characteristics of suspicious lesions over time. You need to consult with a dermatologist if you notice any type of change on the skin or mole.

  • Asymmetry – Most normal moles are symmetrical, which means that both halves are equal. Imagine a line across the middle of the mole, and if the two halves do not match, consult your dermatologist.
  • Edges – If the edges of the mole are ragged and irregular, visit your dermatologist because melanoma often presents with uneven edges.
  • Color – Normal moles have one even color. If your mole is streaked with different colors, including pink, black, tan; or if parts of it had brightened or darkened, visit your dermatologist.
  • Diameter – Benign moles rarely have a diameter greater than 6 millimeters. If the diameter of your mole is greater than 6 millimeters, visit your dermatologist.
  • Evolution – If part of the mole has become raised, visit a dermatologist. Due to melanoma, part of the mole often rises above the skin surface and this happens very quickly. Any change in surface, color, size or diameter needs to be examined.

You can do a mole self-assessment at least once per month, after a shower, while the skin is still wet. In men, melanomas are most common on the back, and in women behind the knees. Also search all hidden parts of the body: between the legs, between the toes, on soles of the feet, behind the knees, on the neck, behind the ears etc. If you notice a change, photograph it and observe whether there have been any changes over the next two weeks. Mole self-assessments are particularly important for teenagers, pregnant women or menopausal women, when hormones have the greatest effects on the body.

Early detection of changes in the mole and timely removal of the changed mole is the only sure way to prevent the occurrence of melanoma.

How are moles assessed?

Atypical moles are not cancer, but there is a higher probability of cells becoming malignant over time. They usually appear in places which get most sun exposure and they vary in shape and size. They can be flat or raised, brown, pink or a mixture of colors. Every atypical mole examined by a dermatologist is assessed based on dermoscopic criteria. In some cases, the entire mole is removed in order to perform a biopsy – to examine the cells under a microscope by a pathologist. Surgery is proposed in cases of moles which have transformed into carcinoma, and surrounding tissue is removed. The wound is stitched and further treatments are also needed in many cases.


Melanoma is different from other types of skin cancer, it is the most dangerous type and is the most difficult to treat. Any change on a mole could potentially be melanoma, so it needs to be examined by a dermatologist. Timely removal of a melanoma is the only way to ensure a successful treatment outcome. Postponement of the intervention could allow the formation of metastases of one of the most aggressive of all cancers.

Planocellular skin carcinoma

This is a non-melanoma skin tumor which can appear as a thickened red knot, flaking, bleeding or forming a scab, but can also appear as a wound which cannot heal. It usually appears on the nose, forehead, eyes, hands or other body parts which are exposed to the sun. Planocellular carcinoma is treatable if treated at an early stage. If the skin carcinoma progresses, treatment depends only on its development stage.

Bowen disease

Bowen disease is also called planocellular skin carcinoma ‘in situ’. This is a type of skin tumor which spreads out to the surrounding tissue. As opposed to the Bowen disease, ‘invasive carcinoma’ expands inwards, into deeper skin levels. If not treated, Bowen disease can turn into invasive planocellular carcinoma.

Basal cell skin carcinoma

This is the most common and least dangerous type of skin carcinoma both in terms of treatment and in terms of the cancer being the least invasive in regard to the surrounding tissue. It is locally invasive, which means that it expands into deeper skin layers and outwards and it can damage surrounding tissue. Basal cell carcinoma spreads slowly and it is most common in adults. It can take many forms, including the appearance of a pearly white waxy growth with visible blood vessels – forming on the nose, neck and face. In its flat form, it can be flesh-colored or tan, or it can present as brown spots most often on the back or chest. It can also appear in the form of a light and indented scar, but this is rarely the case.

Spec. Dr. Svetlana Djurisic, dermatologist
Dermatological clinic DERMATIM, Belgrade