Skin cancer: definition, causes, symptoms, diagnosis and treatment

By Cristiano Antonino Last updated Jun 18, 2023

When we talk about skin cancer, we must distinguish its type and severity in the vast panorama of all tumors that can affect the skin and cells of the dermis

In fact, among the skin tumors we recognize: basal cell carcinoma, squamous cell carcinoma and melanoma

These are three malignant tumors but with very different characteristics, evolutions and prognoses.

Let’s see their characteristics together.

What is non-melanoma skin cancer?

The skin is undoubtedly the most important and extensive organ of the human body, continuously exposed to external agents of all kinds and therefore the target of various pathologies.

As we are already taught in elementary school, the skin is made up of layers such as the epidermis, dermis and hypodermis.

The epidermis, i.e. the most superficial layer of the skin, is mainly made up of melanocytes and keratinocytes.

While the melanocytes are responsible for the production of melanin, a dark substance which gives color to the skin and which has the function of protecting it from UV rays, the keratinocytes, present in all its layers, represent the last stage of the keratinocyte life cycle and have mainly a protective function from attacks by pathogenic organisms, heat, UV radiation and water loss being responsible for the formation of the hydrolipidic film which characteristically protects the body from the outside and prevents the body from losing the water of which it is mainly composed .

From keratinocytes spinocellular carcinomas can originate (when they come from the outermost keratinocytes of the epidermis) or basal cell carcinomas (or basaliomas) when they develop in the deeper layer (stratum basale).

These are called non-melanoma skin cancers to distinguish them from melanomas, which we will discuss later.

Basal cell carcinoma

Among the most common skin cancers is basal cell carcinoma, which affects a very significant percentage of the population every year.

It is a malignant tumor that develops, as we have seen, on the epidermis, due to some genetic mutations often linked to cellular damage which determines an incorrect repair of the DNA of these cells.

Sadly, every year we witness awareness campaigns on exposure to UV rays from the sun, which still remain among the main causes linked to the development of skin cancers.

Signs of basal cell carcinoma: It is distinguished by being a particular skin sign, which can appear on the skin of the face, hands, ears and scalp, on the mouth, genitals and even on the toes.

It looks like a small lesion which however tends to extend, until it becomes important and profound.

It usually appears as a whitish or pearly bump with visible blood vessels that may also form a crust.

Basal cell carcinomas are also those that appear brown and scaly, especially on the back and chest.

They can appear suddenly: it is therefore advisable to go to the doctor immediately for an objective evaluation, so that the situation progresses and becomes more invasive.

How to diagnose basal cell carcinoma: in addition to the objective examination by the doctor, a biopsy is performed (taking tissue from the skin for observation under a microscope).

The treatment: we proceed with a surgical intervention aimed at removing the skin of the basal cell carcinoma, choosing among the various techniques present in medicine based on the size and evolution of the carcinoma.

Squamous cell carcinoma

It is a malignant tumor which, as the name implies, affects the squamous cells.

It is the first cause of carcinoma due to excessive exposure to the sun, whose UV rays cause these important lesions.

Unlike melanoma and basal cell carcinoma, squamous cell carcinoma looks like a real “wound”.

Among skin cancers, it is the least dangerous because it tends to remain in place and almost never metastasizes to adjacent tissues.

However, it should never be underestimated.

Signs of Squamous Cell Carcinoma: As mentioned earlier, this tumor looks like a wound and produces bleeding and crusting.

How to diagnose squamous cell carcinoma: following the physical examination by the dermatologist, a biopsy is performed by taking a small piece of tissue.

The treatment: the skin wound is surgically removed, opting for techniques such as laser therapy, curettage, cryotherapy, photodynamic therapy, Mohs surgery, surgical excision.

Sometimes topical drugs or radiation therapy can be used to kill the cancer cells.

Melanoma

Skin melanoma is a malignant tumor that starts from melanocytes, located in the basal layer of the epidermis.

Although less frequent than basal cell carcinoma, melanoma remains to all intents and purposes a dangerous tumor that must be treated as soon as possible.

It can be generated both on healthy skin and without apparent lesions, or following a trauma or burn, or starting from a mole already present on the skin. The causes of its occurrence can be the most diverse.

Signs and symptoms of melanoma: it is usually the patients themselves who notice that something is wrong from an objective examination, such as the sudden change in the appearance of a mole.

This is the first alarm bell, which can be accompanied by enlarged lymph nodes, nodules, papules, itching, skin ulcers, macules, rashes or bleeding or inflamed margins.

The appearance of the melanoma is asymmetrical, with irregular edges, black or polychrome in color, and often large in size.

How melanoma is diagnosed: in addition to the objective examination, the doctor proceeds with a biopsy (taking tissue from the skin for observation under a microscope).

Then follow radiography, liver ultrasound and any abdominal, pelvic and cerebral CT scans to evaluate any distant metastases.

The treatment: the removal of the melanoma takes place surgically, if the melanoma is taken in an initial state, in order to remove it in depth.

If needed, the patient will follow cycles of chemotherapy and/or radiotherapy.

We looked at what the signs, symptoms, diagnoses, and various treatments are related to skin cancers.

Now let’s see in particular what the different types of melanoma are, of which at least four are known.

Skin cancer, the various types of melanoma

Plane melanoma: it is a lesion that grows protruding outwards, and it is also the most frequent form of melanoma known.

Nodular melanoma: also known as cupoliform melanoma, this variant is quite dangerous since it tends to penetrate deeply and therefore invade other districts of the body, and has a high risk of metastatic progression.

Melanoma in situ: Lentigo maligna (or melanoma in situ) is initially a flat spot, which then slowly evolves over the years. It is rarely a lethal form.

Acral-Lentiginous Melanoma: Acral-Lentiginous Melanomas are defined as those that develop in areas such as the soles of the feet and the palms of the hands. It differs from classic melanoma because this particular type of melanoma also affects people with very dark skin who usually have a lower risk of developing melanoma.

Risk factors

Patients at risk are defined as those who, in general, expose themselves excessively to the sun’s UV rays without the necessary protections.

However, there are some categories of people who are more likely than others to develop melanoma, such as:

Subjects in adulthood; more people aged 30 and over are affected by melanoma, with a higher incidence for the over 50s.
repeat offenders; people who have previously had melanoma or skin cancer.
Caucasian people; people with very light, diaphanous skin, especially if with light eyes and reddish hair are more sensitive to UV rays.
People with freckles.
Those who constantly submit to tanning beds and lamps.
Familiarity; people who already have other cases of melanoma and skin cancer in the family.
People with many moles on the body.
People who work a lot outdoors (farmers, fishermen, etc.).
Cigarette smoke.
Insufficiency of the immune system.
AIDS.
Higher incidence for men.

Skin cancer prevention

Among the best advice that can be given to avoid the onset of skin cancer, there is certainly that of always protecting yourself from UV rays by constantly applying a maximum grade sunscreen.

Even if you have olive-colored skin that tends to tan, protect yourself with a protection factor of 50+ or total, the only one able to partially counteract the onset of skin cancer.

So avoid exposing yourself to the sun during the hottest hours, wear sunglasses and check your skin often.

Ask friends, family and companions to check the skin where you can’t, such as in the back or anus area, and always consider the appearance of any new symptom even if it seems minor.

The various therapies

As illustrated, all skin cancers are usually treated with surgical eradication, with melanomas being the most focussed.

For the other types, if the tumor is located in a superficial layer, it is possible to opt for interventions with local anesthesia such as curettage and electrodrying.

The doctor could choose Mohs surgery, or the removal of very thin layers of tissue to make sure of the tumoral nature of the lesion.

If not, surgical removal will be much better from an aesthetic point of view.

However, the most common is laser surgery, used for both squamous cell and basal cell tumors.

Cryotherapy – i.e. burning the tumor with liquid nitrogen – is also very common, as is the application of chemotherapy drugs.

Where necessary and essential, as in the case of melanomas, radiotherapy and systematic chemotherapy of the whole body will also have to be used.

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