Skin cancer: symptoms, causes, treatment

Skin cancer is the presence of abnormal cells in the skin that multiply uncontrollably and form a carcinoma. Depending on the type of cancer, these cells may remain localized in the skin, so-called “in situ” or localized cancer, or metastasize to lymph nodes close to the tumor or even to other organs (invasive melanomas).


Basal cell carcinoma, squamous cell carcinoma or squamous cell carcinoma, melanoma, which are the most serious?

The nonmelanoma carcinoma family includes two types: basal cell carcinomas and squamous cell carcinomas. These two types of skin cancer are the most common.

The third type of skin cancer, the most dangerous, is melanoma; it develops from melanocytes in the skin.


– Basal cell carcinoma

Basal cell carcinomas develop from the epidermis. They are the most common of all skin cancers. There are several variants: the superficial form, the modular form, and the infiltrating form. These types of skin cancers develop mostly in people who are exposed to a lot of sun ultraviolet light and form on areas that are exposed to the sun. These carcinomas often occur on the face, arms, back, etc. Fortunately, they are the most curable of all skin cancers. It develops very slowly and never metastasizes.


– Squamous cell skin cancer or squamous cell carcinoma

Squamous cell carcinomas develop from keratinocytes (squamous skin cells) and are more aggressive skin cancers than basal cell carcinomas because they, although rare (1% of cases), can metastasize. This disease accounts for 20% of skin cancers. They are directly related to ultraviolet light, but especially affect fair-haired and fair-skinned people. Sometimes it develops on so-called precancerous lesions – actinic keratoses. It can also appear on burn scars or chronic wounds.


– Melanoma

Melanoma accounts for about 10% of skin cancers, but it is a serious cancer that can occur at any age, but is more likely to develop in people who received sunburns in childhood, before the age of eight. In most cases, melanoma develops gradually on a perfectly healthy skin surface, in the form of a small pigmented spot. But it can also develop, in about 15-20% of cases, from a simple mole (nevus) that begins to transform. Melanomas are classified according to their thickness: when they are less than 0.8 millimeters thick, they are not very aggressive, from 1 to 2 millimeters thick they are intermediate, and when they are over 2 millimeters thick, they are the most aggressive.

Melanomas are cancerous tumors that form from the cells responsible for coloring the skin and eyes. In 90% of cases, melanomas occur on the skin, but they can also appear in the mouth, nose, sinuses, and rectum, as well as on the genitals. They can occur at any age. Melanomas make up 10% of skin cancers, but are the most dangerous because they can progress quickly.


There are four forms of melanoma:


Superficially spreading melanoma

Superficially spreading melanoma is the most common form of melanoma (70-80% of all cases). It is mostly associated with sunburns in childhood, especially in fair-skinned people. Superficial extensive melanoma appears as an irregular brown or black patch on the neck, chest, and legs. It gradually enlarges over several years and then changes rapidly when it begins to sprout deep into the skin.


Dubreuil’s melanoma

Dubreuil’s melanoma, which accounts for 5 to 10% of melanomas, is most common in people over 50 years of age and begins with the appearance of a brown spot on the face, neck, or back of the hands. Like extensive superficial melanoma, it grows first on the surface and then penetrates the deeper layers of the skin. It is associated with overexposure to sunlight.


Acral lentiginous melanoma

Acral lentiginous melanoma is more commonly seen in people with very dark or black skin. In the form of a spot or nodule, it usually develops in the area of the nail bed, on the palms of the hands, soles of the feet, or under the fingernails. It can easily be confused with a wart or callus.


Nodular melanoma

Nodular melanoma accounts for 10-15% of melanomas. It appears as a normal or dark-colored spot raised above the rest of the skin. This type of skin cancer most commonly occurs on the head, scalp, neck, or torso (but can appear anywhere on the skin, even if it is protected from the sun). It grows quickly and tends to sprout immediately deep into the skin without spreading to the surface.


How does melanoma develop?

Melanomas arise from a few cancer cells that appear on the surface of the skin when exposed to ultraviolet light.  These cells then multiply, and after a while begin to rapidly invade the deeper layers of the skin, at which point the melanoma becomes invasive. In the invasive form of this type of skin cancer, and if untreated, the cancer cells gradually migrate through the lymph flow and bloodstream, then settle and multiply in the liver, lungs, bones, brain, etc. These secondary tumors are called metastases.


What are the symptoms?

An unusual mole, a spot on the skin that has changed color, a pimple that won’t go away. A careful skin exam can help you detect skin cancer at an early stage. As a preventive measure, it is recommended that you visit your dermatologist once a year to examine all areas of your body, including those that you cannot see yourself.


Moles or cancer: how can you tell the difference?

There are dozens of moles on our bodies. While most are benign, some can be cancerous, so it’s important to keep an eye on them. How can you tell a normal mole from a melanoma?

Self-monitoring of your skin condition contributes to the early detection of lesions caused by skin cancer.



The diagnosis of skin cancer involves a clinical examination of the skin and microscopic analysis of a sample of the suspected lesion.

When examining a patient’s skin, the dermatologist may use a special device called a dermatoscope, which allows you to see through the most superficial layer of skin. Or use a lamp that emits ultraviolet light – a Wood’s lamp – to look for abnormal pigmentation in the skin.


If the lesion seems suspicious, the dermatologist will remove it and a few millimeters around the lesion under local anesthesia and send it to the lab for microscopic analysis, and close the wound with one or two stitches.


At our Health and Prevention Center, in Geneva, we perform skin cancer tests with a more accurate machine than a dermatoscope. We’re talking about a confocal microscope. A machine that allows us to image a single skin cell. This method allows us to study the epidermis, the papillary layer of the dermis and the resolution of the upper reticular layer of the dermis is comparable to histology, therefore, there is no need to dissect tissue for biopsy. Read more…


If the analysis confirms it is a cancerous lesion, your doctor will decide to do additional tests to look for possible metastases: blood tests, ultrasound of adjacent lymph nodes, CT scan, MRI, etc.




– Treatment for skin cancer, and melanoma in particular, varies depending on the stage of its development. The main method of treatment for skin cancer is surgical excision of the tumor and possibly the affected lymph nodes, as well as medications.


– Chemotherapy, to block the reproduction of abnormal cells.


– Immunotherapy, to stimulate the immune defense of the patient.

– Targeted therapy, which targets the abnormal protein in cancer cells.


– Radiation therapy, irradiation, used only to treat metastases.




– Treatment of basal cell carcinomas, cutaneous squamous cell carcinomas, and actinic keratoses (precancerous lesions) is not much different from treatment of melanomas and also primarily involves surgery.


If surgery is not possible, the doctor may also prescribe :

– Cryotherapy (destruction of the lesion with liquid nitrogen);

– Electrocoagulation (electric scalpel or laser, as in the treatment of warts);

– Localized radiation therapy;

– Immunostimulant cream for several weeks;

– Dynamic phototherapy (the lesion site is exposed to a specific spectrum of light after sensitization with a drug).


Causes and risk factors


Frequent exposure to the sun

The role of sun exposure in the development of skin cancer is well known. Although the vast majority of patients are aware of the harmful effects of sun exposure, few take preventative safety measures. On average, 6 out of 10 skin cancers are known to be directly related to excessive exposure to UVA and UVB rays, the latter causing mutations in cell genes and the latter altering cell membranes and nuclei. Alternating winter breaks from sunbathing and then a strong summer tan creates an additional risk of skin cancer.


Excessive sun exposure as a child

Sunburns as a child are associated with the development of pigmented nevi, which can later cause the risk of melanoma.


Tanning in a tanning bed

Many studies point to an increased risk of developing skin cancer when using tanning beds for tanning.  Tanning beds are even prohibited for children under the age of 18 because their skin is especially fragile.


Familial predisposition

Approximately 10% of malignant melanomas occur in a family whose members have had 2 melanomas within 3 generations. That’s why family members who already have melanoma should be very vigilant – systematically check the condition of their skin with a dermatologist and limit their exposure to the sun.


Number of moles

The presence of a large number of moles (50 or more) is a risk factor. Every odd mole (large, irregularly shaped, pinkish-brown in color) should be under medical supervision.


Medical exposure and medication

People who have had a large number of radiation therapy sessions or exams with radiation tend to be at greater risk for skin cancer. In addition, in rare cases, certain medications may contribute to the development of carcinoma (your doctor should warn you about this when prescribing the medication).


Phenotype (skin type)

People with fair skin are more likely to develop skin cancer when exposed to sunlight because of their relative lack of pigmentation.


See your doctor if :

If you have unusual skin lesions, a pinkish spot on your face, a modified mole, or if it itches, you should see a dermatologist. Particular caution should be exercised by people with very fair skin and those with many birthmarks.


How dangerous is skin cancer?

Skin cancer is curable in certain cases:

– If it is not melanoma

– If it is detected at an early stage and it is not metastatic

In rare cases, skin cancer will metastasize. But it can happen with melanoma or, in even rarer cases, squamous cell carcinoma. Fortunately, new treatments are increasing survival rates for metastatic skin cancer.


Prevention of skin cancer


– The first step is to use protective creams and apply them every 2 hours when out in the sun. Preferably, the sun protection factor should be higher than 30. Do not forget to apply sunscreen even if you are already sunburned.

– It is very important for children to wear clothes in the sun up to the age of 8. In addition, it is important to avoid exposure from 12 to 5 p.m.

– Any change in the skin that does not go away, a wound that has not healed, a pimple that does not go away, should be consulted, because the sooner cancer treatment is started, the better the chances of a cure.



At our Medical Center in Geneva, you can also undergo a non-surgical skin cancer consultation.

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