Skin basal cell carcinoma (basal cell carcinoma). Basal cell skin cancer, photos, treatment and prognosis

The main malignant skin tumors are: basal cell carcinoma (basal cell carcinoma), squamous cell carcinoma and melanoma. Other sections of the site are devoted to basal cell carcinoma and melanoma.
Squamous cell skin cancer is the second most common malignant disease after basal cell carcinoma. This is what oncologists simply call “skin cancer.”
It can appear without any prerequisites or harbingers. And it can arise from precancerous skin diseases, such as actinic (solar) keratosis, keratoacanthoma, cutaneous horn, Bowen's disease.
Precancerous lesions can exist for many years without causing concern. Suddenly, precancer turns into a malignant form- this is very common occurrence. For many people, this transition to squamous cell skin cancer is misleading and delays timely treatment. It seems to people that they simply injured themselves, or caught a cold, or overheated a tumor, or that side effects medicines. And, over time, it will return to its previous size.

Skin cancer in the form of a dense node on the dorsum of the finger. Similar to keratoacanthoma.

The ulcer on the leg appeared due to problems with blood vessels. Then it turned into skin cancer.

Squamous cell skin cancer. What is the reason for the appearance?

Accumulated over a lifetime ultraviolet radiation- the main leading cause of the development of squamous cell skin cancer. This is evidenced by statistics in the form of the number of cases per year per hundred thousand population (morbidity).
Most tumors appear on exposed areas of the body in fair-skinned patients over 60 years of age. Between 70% and 80% of tumors appear on the head and neck. Especially on the lower lip, ears, and scalp. Slightly less common are lesions on the dorsum of the hand, forearm, anterior surface of the leg and dorsum of the foot. Squamous cell skin cancer is much less common in areas not exposed to sunlight.
The human papillomavirus (HPV) also makes its contribution. It can cause both precancerous lesions and skin cancer. HPV types 16, 18, 31, 33, 35, 39, 40, 51, 60 are often found in areas of squamous cell skin cancer; HPV types 5, 8, 9 were also found. Less important is decreased immunity, constant trauma, inflammatory diseases skin, contact with harmful chemicals (especially arsenic compounds).

Incidence of squamous cell skin cancer.

The incidence of skin cancer is the number of affected people per 100 thousand population. Among white-skinned people in the southern regions it increases significantly. In the USA, for example, on average, the incidence is 10 per 100,000 population, and in Hawaii it is already 62 per 100,000. The rates for white-skinned people in Australia are approximately the same. In Russia, with statistics, everything is much more confusing. Many tumors are treated without proper histological examination. And, even if there is one, the patient may not be registered, considering the disease too mild.
In the USA, squamous cell skin cancer sooner or later will appear in 9-14% of men and 4-9% of women. The incidence increases sharply with age and after intense sunbathing throughout life. Men get sick about twice as often as women. Over the past two decades, it has been celebrated sharp increase in incidence. Apparently this is due to tanning fashion.
Most people (73%) will only develop one tumor in their lifetime. A smaller number (21.2%) will develop two to four lesions of squamous cell skin cancer. And only a small number of patients will develop several tumor foci during their lifetime.

Squamous cell skin cancer, its symptoms.

The signs of squamous cell skin cancer and its danger depend largely on the degree of differentiation. Highly differentiated means that cancer cells under a microscope are quite look like normal, such cancer is the least dangerous. Poorly differentiated most dangerous, its cells under a microscope very different from normal. Moderately differentiated occupies an intermediate position.
A sign of squamous cell skin cancer can be considered the appearance of a plaque or node with a weeping, bleeding surface or with dense yellowish crusts. The density of the formation varies significantly in each case. Symptoms of poorly differentiated cancer are the node is soft to the touch and lacks horny crusts. Usually, the skin cancer on the surface of which has yellow horny masses, and dense to the touch.
Cancer should be suspected in any case if there is a suspicious formation that does not go away within a month. Rapidly growing squamous cell carcinoma can grow within several weeks, its symptoms are pain, softness of the node.
Greatest similarity squamous cell skin cancer has amelanoma, inflammatory ulcer, pyogenic granuloma, basoscamous or ulcerative basal cell carcinoma.
If there is any doubt about the diagnosis, it is indicated tumor biopsy followed by histological examination. The pronounced nature of the thickening of the skin surrounding squamous cell carcinoma also helps in diagnosis.
If the tumor is up to 2 cm in diameter and is highly differentiated, only examining the regional lymph nodes with the doctor’s fingers (palpation) is sufficient. Compaction of the lymph node and an increase of more than 1.5 cm is a common sign of metastasis in it. It is possible to perform a biopsy from the node using a syringe needle and an ultrasound machine.
If the tumor is more than 2 cm in diameter and/or is poorly differentiated, it is advisable to do an ultrasound of the regional lymph nodes, even if everything is fine on palpation. And, sometimes, conduct a more in-depth examination.

Squamous cell poorly differentiated skin cancer. Grows quickly, bleeds, soft to the touch.

Highly differentiated skin cancer of the upper eyelid. It grows for a relatively long time and has horny masses on the surface.

Stages of skin cancer. TNM.

Squamous cell skin cancer is divided into stages, depending on the characteristics of the tumor. To determine the stage, it is first selected with suitable values ​​in the TNM system. Where T characterizes the size of the tumor, N refers to regional lymph nodes, and M encrypts the fact of the absence or presence of distant metastases.

TNM values ​​for staging squamous cell skin cancer.

Index	Its signs
Tis	The tumor has just appeared and does not invade the basement membrane of the epithelium (regardless of the size of the lesion). Otherwise known as Bowen's disease (cancer in situ)
T1	up to 2 cm
T2	From 2 cm to 5 cm
T3	more than 5 cm
T4	Germination into tissues located under the skin (muscles, cartilage, bones)
N0	There is no lesion in regional lymph nodes
N1	There are metastases to the nearest regional lymph nodes
M0	There are no metastases in lymph nodes from other regions or in internal organs
M1	There are metastases to the lymph nodes from other regions, or to any other organ (liver, lungs, bones)

Determination of skin cancer stage based on TNM features.

Clinical stage of skin cancer	T	N	M
0 Stage	Tis	N0	M0
Stage I	T1	N0	M0
Stage II	T2	N0	M0
Stage II	T3	N0	M0
III Stage	T4	N0	M0
III Stage	Any T	N1	M0
Stage IV	Any T	Any N	M1

Forecast. Metastases of squamous cell skin cancer.

Squamous cell skin cancer mainly destroys tissue only in the area of ​​​​appearance and causes metastases relatively less frequently than cancer of other organs. But the possibility of metastasis is still higher than that of basal cell carcinoma. First of all, the lymph nodes closest to the tumor (regional) are affected.
On average, abroad high level early diagnosis . In this regard, the treatment results are quite good. The relapse rate within five years does not exceed 8%. The risk of metastases to nearby lymph nodes or internal organs (usually the lungs) is, on average, 5%. IN Russia indicators may vary significantly due to later diagnosis. Metastases of skin cancer (like any other) can appear several years after tumor removal, most often within 1-3 years. Most likely, they are large tumors that recur and grow into the nerves.
Squamous cell carcinomas that invade the subcutaneous fat or are more than 4 mm in depth are almost 8 times more likely to metastasize (45.7% risk of metastasis) than tumors located within the upper layers of the skin.
Tumor size is the most important factor affecting the risk of recurrence or metastasis. When the tumor grows more than 2 cm, the risk of relapse increases by 2 times and the risk of metastases increases by 3 times.
It has long been noted that squamous cell skin cancer from areas with scars, from ulcers, from areas of burns and radiation, much worse according to forecast.

Squamous cell skin cancer. The influence of tumor features on the number of relapses and metastases.

Sign	Relapse rate	Metastasis rate
Size
less than 2 cm	7.4%	9.1%
more than or equal to 2 cm	15.2%	30.3%
Depth
less than 4 mm (1-2 degree of invasion according to Clark)	5.3%	6.7%
more than or equal to 4 mm (4-5 degree of invasion according to Clark)	17.2%	45.7%
Degree of differentiation
Highly differentiated	13.6%	9.2%
Poorly differentiated	28.6%	32.8%
Region
We irradiate with the sun	7.9%	5.2%
Ear	18.7%	11.0%
Lips	10.5%	13.7%
Skin cancer from scar	Not studied	37.9%
Previously treated (relapse)	23.3%	30.3%
With germination into nerves	47.2%	47.3%
Proven decreased immunity	Not studied	12.9%

Treatment of squamous cell skin cancer.

In general, the success of treating stage 1 squamous cell carcinoma (up to 2 cm in diameter) is quite good. The effectiveness of treatment is assessed by the absence of relapses and metastases for 5 years. Often, this effectiveness is higher than for basal cell carcinoma. Perhaps this is due to the more wary attitude of doctors and more clear outline of the tumor.
The final result of treating squamous cell skin cancer by any method depends on the skills and experience of the doctor more than on the instruments used. In the right hands, treatment is more than 90% effective, regardless of the method chosen.

Surgical treatment of skin cancer.

The surgical method is the most common. It consists of cutting out a flap where the squamous cell skin cancer is located, with a proper indentation from the edge of the tumor. A skin tumor up to 2 centimeters is excised with a margin of 4 mm. Tumors more than 2 cm in diameter, as well as poorly differentiated, penetrating the skin, or located in dangerous areas ( hairy part heads, ears, eyelids, nose, lips) require excision with a margin of more than 6 mm.

Mohs method against squamous cell skin cancer.

Mohs removal is preferable to conventional surgery in cases of large, deep tumors. Histological examination is carried out at the time of surgery. Allows you to continue removal in the desired direction if squamous cell skin cancer cells are found in the edge of the flap. The Mohs method gives the least number of relapses and metastases. Contraindications and cosmetic results are the same as for conventional surgical treatment.

Radiation treatment of squamous cell skin cancer.

Radiation treatment also quite common. But its effectiveness seriously inferior surgical treatment . Indicated in those patients who cannot undergo surgical treatment.
It may also be indicated in cases where the expected cosmetic results of surgical treatment are not at all ideal. For example, when squamous cell skin cancer appears on the lips, lower eyelid, and occasionally on the ears. Radiation therapy may be prescribed as an additional treatment after surgery. This is especially true when, under a microscope, squamous cell skin cancer cells are found in the edge of the removed skin flap (despite the indentation). Or in case of penetration into nerves.
The scar from radiation treatment for squamous cell skin cancer begins to look worse and worse over time. Radiation treatment can also be carried out on regional lymph nodes. Over time, many new tumors may appear due to the radiotherapy itself.

Treatment of skin cancer with liquid nitrogen (cryodestruction).

Squamous cell skin cancer, like basal cell carcinoma, can be treated with liquid nitrogen (cryodestruction). The tumor is literally frozen, turning into a piece of ice. During thawing, small ice crystals destroy cell membranes and clog blood vessels. Within a few weeks, the tumor masses are rejected and replaced by a scar similar in structure to the skin. The effectiveness of the method depends on the performer and the availability of proper equipment.

Electrodissection and curettage.

Electrodissection and curettage of squamous cell skin cancer are possible only in extremely rare cases, with very small and relatively benign tumors. With this method, the tumor is scooped out with a special spoon - a curette, and also burned using a coagulator to stop the bleeding. The effectiveness of treatment with this method is extremely dependent on the performer.

Prevention of skin cancer.

• All patients diagnosed with skin cancer or precancerous lesions should avoid sun exposure. Especially during hot periods from 10 am to 4 pm.
• Use sunscreen with a protection factor of at least 15.
• Regular monitoring by an oncologist and treatment of precancerous diseases using cryodestruction or other methods will help to avoid unnecessary surgical interventions.
• As a preventative measure, it is possible to use retinoids (isotretinoin) in ointments (retinoic ointment).
• Periodic use of 5-fluorouracil cream may reduce the severity of precancerous lesions and improve the appearance of the skin, but a reduction in the incidence of cancer has not been proven.
• Examine your skin once a month for the presence of new growths.

In contact with

The most common type of non-melanoma malignant skin tumors is basal cell skin cancer (basal cell carcinoma), which accounts for 45 to 90% of all skin cancers. Incidence rates vary significantly, from low in regions with low solar radiation to high in regions with hyperinsolation.

IN medical statistics There is no special recording of the incidence of basal cell carcinoma. At the same time, the incidence in the Russian Federation of any type of non-melanoma epithelial tumor per 100,000 population is about 43 people and ranks first in the structure of all cancer incidence. Its annual increase is approximately 6% among the male population and 5% among the female population.

Risk factors

Basal cell skin cancer is a slow-growing and recurrent malignant formation that develops in the epidermal layer or skin appendages, has destructive growth (can penetrate into surrounding tissues and destroy them), and in rare cases - the ability to metastasize and lead to death outcome.

The etiopathogenesis of the tumor is not well understood. However, in the mechanisms of disease development, the main role of one (SHH) of the intracellular molecular signaling pathways that control cell metabolic processes, their growth, motility, DNA-based RNA synthesis and other intracellular processes is considered to be proven.

It is assumed that the difference in the morphological forms and biological behavior (degree of aggressiveness) of basal cell skin cancer is due to genetic and suprogenetic regulatory mechanisms. The disease begins to develop as a result of mutations in a certain chromosomal gene encoding the receptor of the SHH signaling pathway, resulting in its pathological activity with the subsequent growth of atypical cells.

Factors contributing to gene mutation and the implementation of mechanisms for the development of cancer cells are:

1. The influence of sunlight. Their role is given the utmost importance. Moreover, if the intensity of ultraviolet rays is more important for development, then for development it is the duration, “chronic” nature, that is, the cumulative effect of their exposure. This probably explains the difference in localization malignant tumors: melanomas, as a rule, develop in closed areas of the body, basal cell carcinomas - in open ones.
2. Age and gender, the influence of which is partly explained by the cumulative effect of UV rays - in 90% of basal cell carcinoma develops at the age of 60 years, and average age applying for medical care on this occasion is 69 years old. Skin cancer occurs more often in men compared to women. Most likely, more frequent and prolonged exposure to the sun plays a role in this due to the characteristics of professional activity. At the same time, such a difference in the incidence of the disease in last years increasingly erased due to changes in lifestyle and women's fashion ( open areas body).
3. Exposure of the skin to X-rays and radioactive rays, high temperature (burns), inorganic compounds and arsenic compounds contained in contaminated water and seafood.
4. Chronic inflammatory processes skin, frequent mechanical trauma in the same area of ​​the body, skin scars.
5. Chronic conditions associated with immunosuppression diabetes mellitus, hypothyroidism, HIV infection, blood diseases (leukemia), taking glucocorticoid drugs and immunosuppressants for various diseases.
6. Individual characteristics of the body - a tendency to form freckles in childhood, skin phototype I or II according to the Fitzpatrick classification (in persons with dark skin, basal cell carcinoma develops much less frequently), albinism, genetic disorders (hereditary xeroderma pigmentosum).
7. Localization of the neoplasm. So, the risks of a tumor and its more frequent recurrence are higher when localized in the head, especially the face, neck, and much less with primary lesions, for example, the skin of the back and extremities.

Risk factors for relapse include tumor subtype, its nature (primary or recurrent), and size. In the latter case, an indicator such as the maximum diameter of carcinoma (more/less than 2 cm) is taken into account.

Symptoms of basal cell skin cancer

This tumor is very typical slow growth(many months and even years). The peripheral parts of the lesion have the greatest growth activity. Here the phenomena of cell apoptosis are noted, as a result of which an erosive or ulcerative surface is formed in the center of the neoplasm.

This fact is taken into account during surgical treatment, for choosing the volume of which it is very important to clearly define the boundaries of the peripheral growth zone, since the most aggressive cancer cells are localized there.

In the case of long-term development, the initial stage of basal cell carcinoma gradually passes into the next, which are characterized by infiltration and destruction of deeper underlying soft tissues, periosteum and bone, and metastasis to regional lymph nodes. In addition, pathological cancerous tissues tend to spread along the periosteum along the tissue layers along the nerve branches. The most vulnerable in this regard are the border zones of contact of the embryonic layers, represented, for example, by nasolabial folds on the face.

The histopathological picture is characterized by the presence of cells containing a small amount of cytoplasm and large ovoid-shaped nuclei, which consist mainly of matrix. The index, determined by the ratio of the nucleus to the cytoplasm, significantly exceeds that of normal cells.

Intercellular tissue (stroma) grows along with tumor cells. It is located in bundles between cell cords and divides them into separate lobules. In the peripheral sections, the formation is surrounded by a layer of cells, the arrangement of whose nuclei resembles a palisade. This layer contains cells with a high potential for aggressiveness and malignant growth.

In accordance with clinical and histological characteristics, several subtypes, or variants of basal cell carcinoma, are distinguished.

Nodular (nodular) or solid basal cell carcinoma

Accounts for an average of 81% of all cases of the disease. It is a slowly growing, rounded, pink-colored formation that rises above the healthy surface of the skin, the size of which in its largest diameter can range from several to 20-30 millimeters.

The entire lesion is represented by papules with a pearlescent shiny surface and small branched telangiectasias. The surface of the entire tumor bleeds easily with minor trauma. Its size gradually increases, and over time a crust appears in the center and subsequently an ulcer. Over 90% of formations of this variant are localized in the head (cheeks, nasolabial folds, forehead, eyelids, ears) and neck.

On histological examination, a solid tumor consists of compactly grouped epithelial cells, similar to the cells of the basal layer of the epidermis, between which neutral mucopolysaccharides and glycosaminoglycans are located. These complexes have unclear boundaries and are surrounded by elongated elements, resulting in a characteristic “picket fence” appearance. As a result of the progression of destruction normal tissue small (various sizes) cavities are formed in the form of cystic cells. Calcium salts are sometimes deposited in the destroyed cell mass.

1. Solid form of basal cell skin cancer
2. Sclerosing form

Ulcerative form

It is considered as the result of a natural further development of the previous version. Processes of programmed cell death (apoptosis) in the central zone of the tumor are the cause of destruction of the malignant focus with the formation ulcerative defect, covered with purulent-necrotic crusts, surrounded by an elevation in the form of a pink roller with small “pearls” (nodular thickenings) of a grayish color.

Basal cell carcinoma of the ulcerative form, as a rule, does not metastasize. However, it can exist for up to 10-20 years, during which the ulcers increase from millimeters (1-2) to gigantic sizes (5 cm or more), penetrating deeply into the underlying tissue and destroying surrounding structures as they grow. Advanced cases can cause bleeding, purulent and other complications with a fatal outcome.

Surface form

Approximately 15%. It is characterized by the appearance of a pink spot with raised edges, clearly defined boundaries and a shiny or flaky surface, on which a brown crust often forms. The most common (60%) localization is various parts of the trunk and limbs. Multiple lesions are quite common. As a rule, the disease affects younger people - the average age is 57 years.

This form is characterized by benign growth - existing for decades, the tumor slowly increases in area and, as a rule, does not penetrate into neighboring tissues or destroy them, but after surgical treatment it often recurs in the peripheral parts of the postoperative scar.

Histologically, the formation consists of many complexes that are located only in the upper layers of the dermis up to the reticular layer. Some (about 6%) superficial tumors contain excess melanin and are classified as the pigmented form. They have a brownish or even black color and cause certain difficulties in differential diagnosis with melanocytic tumors.

Superficial form of pathology

Pigmented basal cell carcinoma

Flat or sclerosing form of basal cell carcinoma

Averages 7%. It is a plaque with unclear boundaries, raised edges and a depression. The color of the formation is flesh-colored, ivory with a pearlescent tint or reddish. Visually, it is similar to a “patch” or has the appearance of a scar. There may be small crusts, erosions or telangiectasias on its surface. The predominant areas of localization are the head (especially the face) and neck (95%). The course of the flat form is more aggressive with germination into the subcutaneous fatty tissue and muscles, but there is no ulceration or bleeding.

Infiltrative option

Develops in cases of progression of nodular and flat forms of basal cell carcinoma. It is characterized by a pronounced infiltrative component of the tumor, a tendency to recur after treatment and a more negative prognosis.

Pincus fibroepithelioma

It is a rare type of basal cell carcinoma. It is characterized by localization in the skin of the lumbosacral region and clinical similarity to fibroepithelial polyps or. Histological examination reveals epithelial strands consisting of dark small cells of the basaloid type. The strands are interconnected and extend from the epidermis, sometimes small cysts are visible in them. Elements of the surrounding stroma are often enlarged and edematous, and contain many basophils and capillaries.

Basosquamous or metatypical form

Characterized by the fact that upon histological examination, one part of the tumor has signs of basal cell carcinoma, and the other - squamous cell carcinoma. Some of the metatypical formations are formed as a result of the overlap of these two types of skin cancer. The metatypical variant is the most aggressive in terms of growth, spread and distant metastasis like squamous cell carcinoma.

Basal cell neoplasia syndrome (Gorlin–Goltz syndrome)

A rare autosomal dominant disorder characterized by variable, multiple symptoms. The most characteristic and frequently occurring is a combination of such signs as:

1. The presence of multiple areas of basal cell carcinoma in different parts of the body.
2. Palmar and plantar pits are dark or pink in color, which arise as a result of a defect in the stratum corneum.
3. Cystic formations in the jaw bone that can destroy bone tissue, change the shape of the jaw and lead to tooth loss. Often these cysts are detected by chance on an x-ray.

The course of the syndrome is usually non-aggressive - without involving deep-lying soft tissues and facial bones in the process. Other (also variable) symptoms may include increased sensitivity to sunlight, abnormal skeletal bone development, a large body, and several others. Even within the same family, symptoms and their combination may vary among its members. The presence of neoplasms in at a young age or their multiplicity should be a reason for the presumptive diagnosis of Gorlin syndrome.

Treatment of basal cell skin cancer

According to statistics, about 20% of patients or more with various forms of basal cell carcinoma were treated before seeing a doctor folk remedies or various external medications. Such independent therapy is unacceptable, since it is not only ineffective, but can increase the area and depth of the lesion and even provoke the development of metastases.

Main methods of treatment:

1. Surgical.
2. Close focus radiation therapy.
3. Curettage with electrocoagulation.
4. Cryodestruction.
5. Photodynamic therapy (PDT).
6. Chemotherapy.

Surgical method

It consists of an ellipse-shaped excision within healthy tissue at a distance of 4-5 mm from the tumor borders with mandatory subsequent histological examination of the edges of the removed area. In the case of locally infiltrative growth of the formation, extensive resection is performed followed by plastic reconstructive surgery.

The effectiveness of surgical treatment of the primary tumor is 95.2% with an average follow-up of 5 years. High rates of relapse were noted when the lesion size was more than 10 mm, removal of recurrent tumors, as well as cancer localization in the nose, ears, scalp, eyelids and periorbital area.

In most cases, the microsurgical technique is considered standard. It allows you to preserve unaffected tissue areas as much as possible, which is especially important during operations on the face, fingers and genital area. The method consists of excision of a visually visible tumor, followed by serial layer-by-layer horizontal sections of tissue and their histological examination and mapping. This method makes it possible to achieve clean edges economically.

Close focus radiation therapy using X-rays

The main method in the presence of contraindications for the use of surgical excision. It is indicated mainly for people 60 years of age and older. Beam method can cause diffuse alopecia, radiation dermatitis, provoke the development of malignant neoplasms, etc.

Curettage with electrocoagulation

Used most often in the treatment of basal cell skin cancer, due to high availability, ease of implementation, low cost and quick results. The essence of the method is to remove the bulk of the affected tissue (with exophytic growth of the tumor) using a metal curette and subsequent electrocoagulation of the tumor bed. Its disadvantages are the impossibility of histological control, a high risk of relapse for tumors larger than 1 cm, and unsatisfactory cosmetic results (the formation of areas with reduced pigmentation is also possible).

Cryodestruction using liquid nitrogen

Despite the possibility of outpatient use, the low cost of the procedure and satisfactory cosmetic results, it is rarely used for the treatment of basal cell carcinoma. This is explained by the need for repeated sessions, the impossibility of histological control, and the presence of a high percentage of relapses.

Photodynamic therapy

It is a relatively new technique in which the treatment of basal cell skin cancer with a low-intensity wavelength laser is carried out against the background of the action of a photosensitizer and oxygen. The impact is:

• damage to tumor vessels;
• direct toxic effect on cells of substances that are formed as a result of a light-chemical reaction; these substances lead tumor cells to apoptosis, as a result of which the latter become foreign to the body;
• formation of an immune response to foreign cells.

Chemotherapy

Doesn't have widespread because it is not effective enough. It can be used for superficial lesions of a small area, mainly as an additional remedy to other methods or in cases of contraindications to their use.

With monotherapy, the effectiveness of the method can reach 70%. Systemic chemotherapy for basal cell skin cancer consists of drip intravenous administration Cisplastin in combination with Doxorubicin according to the scheme or Cisplastin in combination with Bleomixin and Methotrexate also according to the scheme. In addition, creams, emulsions and ointments containing bleomycin, cyclophosphamide, prospidin, and methotrexate are produced for topical use.

Forecast

The prognosis for basal cell skin cancer is generally quite favorable, since metastasis occurs mainly in cases of transformation of its various forms into metatypical, which metastasizes on average in 18%.

In practice, it is especially important to carry out timely differential diagnosis of dermatological pathology and, in particular, different types of carcinoma, which allows you to choose the right method of therapy, prevent the possibility of relapse and achieve acceptable cosmetic results.

Basalioma (syn. basal cell carcinoma) is the most common malignant epithelial neoplasm of the skin (80%), arising from the epidermis or hair follicle, consisting of basaloid cells and characterized by locally destructive growth; metastasizes extremely rarely.

Usually develops after 40 years of age due to prolonged insolation, exposure to chemical carcinogens or ionizing radiation. More common in men. In 80% of cases it is localized on the scalp and neck, in 20% it is multiple.

Clinically, the following forms of basal cell carcinoma are distinguished:

superficial– characterized by a flaky pink spot, round or oval in shape with a thread-like edge, consisting of small shiny pearl nodules, dull pink in color;

ABOUT downy begins with a dome-shaped nodule, reaching a diameter of 1.5–3.0 cm over several years,

ulcerative develops primarily or by ulceration of other forms; basalioma with a funnel-shaped ulceration of a relatively small size is called ulcus rodeus (“corroding”), and spreading deeper (down to the fascia and bone) and along the periphery is called ulcus terebrans (“penetrating”);

scleroderma-like basalioma has the appearance of a dense whitish plaque with a raised edge and telangiectasia on the surface.

Histologically, the most common (50–70%) type of structure, consisting of strands of various shapes and sizes and cells of compactly located basaloid cells, resembling a syncytium. They have round or oval hyperchromatic nuclei and scanty basophilic cytoplasm, along the periphery of the strands there is a “picket fence” of prismatic cells with oval or slightly elongated nuclei - a characteristic sign of basal cell carcinoma. Mitoses often occur; the cellular fibrous connective tissue stroma forms fascicle structures, contains a mucoid substance and an infiltrate of lymphocytes and plasma cells.

The course of basalioma is long. Relapses occur after inadequate treatment, more often with a tumor diameter of more than 5 cm, with poorly differentiated and invasive basal cell carcinomas.

The diagnosis is established on the basis of clinical and laboratory (cytological, histological) data.

Treatment of solitary basaliomas is surgical, as well as using a carbon dioxide laser, cryodestruction; when the tumor diameter is less than 2 cm, intralesional administration of intron A is effective (1,500,000 units every other day No. 9, the course consists of two cycles). For multiple basal cell carcinomas, cryodestruction, photodynamic therapy, and chemotherapy are performed (prospidin 0.1 g intramuscularly or intravenously daily, 3.0 g per course). X-ray therapy (usually close-focus) is used to treat tumors located near natural openings, as well as in cases where other methods are ineffective.

Squamous cell carcinoma

Squamous cell skin cancer (syn.: spinocellular cancer, squamous cell epithelioma) is a malignant epithelial tumor of the skin with squamous differentiation.

Affects mainly elderly people. It can develop on any part of the skin, but more often in open areas (upper face, nose, underlip, dorsum of the hand) or on the mucous membranes of the mouth (tongue, penis, etc.). As a rule, it develops against the background of skin precancer. Metastasizes lymphogenously with a frequency of 0.5% in malignant solar keratosis to 60–70% in squamous cell carcinoma of the tongue (on average 16%). Foci of squamous cell skin cancer can be solitary or primary multiple.

Clinically, tumor and ulcerative types of skin cancer are distinguished.

Tumor type, initially characterized by a dense papule surrounded by a halo of hyperemia, which turns over the course of several months into a dense (cartilaginous consistency) sedentary red-pink node (or plaque) fused with subcutaneous fatty tissue with a diameter of 2 cm or more with scales or warty growths on the surface (warty variety), easily bleeds at the slightest touch, necrotizing and ulcerating; its papillomatous variety is characterized by more vigorous growth, individual sponge-like elements on a broad base, which sometimes have the shape of a cauliflower or tomato. Ulcerates in the 3rd–4th month of the tumor’s existence.

Ulcerative type characterized by a superficial ulcer irregular shape with clear edges, spreading not in depth, but along the periphery, covered with a brownish crust (superficial variety); the deep type (spreading along the periphery and into the underlying tissues) is an ulcer with a yellowish-red color (“greasy”) base, steep edges and a lumpy bottom with a yellow-white coating. Metastases to regional lymph nodes occur in the 3rd–4th month of tumor existence.

Histologically, squamous cell skin cancer is characterized by cords of cells of the spinous layer of the epidermis proliferating into the dermis. Tumor masses contain normal and atypical elements (polymorphic and anaplastic). Atypia is manifested by cells of different size and shape, hyperplasia and hyperchromatosis of their nuclei, and the absence of intercellular bridges. There are many pathological mitoses. There are keratinizing and non-keratinizing squamous cell carcinoma. Well-differentiated tumors demonstrate pronounced keratinization with the appearance of “horny pearls” and individual keratinized cells. Poorly differentiated tumors do not have pronounced signs keratinization, they contain strands of sharply polymorphic epithelial cells, the boundaries of which are difficult to determine. The cells have different shapes and sizes, small hyperchromic nuclei, pale shadow nuclei and nuclei in a state of decay are found, pathological mitoses are often detected. Lymphoplasmacytic infiltration of the stroma is a manifestation of the severity of the antitumor immune response.

The course is steadily progressive, with germination into the underlying tissues, pain, and dysfunction of the corresponding organ.

The diagnosis is established based on the clinical picture, as well as the results of cytological and histological studies. Differential diagnosis carried out with basal cell carcinoma, keratoacanthoma, solar keratosis, Bowen's disease, cutaneous horn, etc.

Treatment is carried out by surgical removal of the tumor within healthy tissue (sometimes in combination with x-ray or radiotherapy), chemosurgical treatment, cryodestruction, photodynamic therapy and etc. The choice of treatment method depends on the stage, localization, extent of the process, the nature of the histological picture, the presence of metastases, age and general condition of the patient. Thus, when the tumor is localized in the area of ​​the nose, eyelids, lips, as well as in elderly people who are unable to undergo surgical treatment, radiotherapy is often performed. The success of treatment largely depends on early diagnosis. Prevention of squamous cell skin cancer consists primarily of timely and active treatment of precancerous dermatoses. The role of sanitary propaganda among the population of knowledge about the clinical manifestations of squamous cell skin cancer is important, so that patients consult a doctor as early as possible when it occurs. It is necessary to warn the population about the harmful effects of excessive sun exposure, especially for blondes with fair skin. Compliance with safety precautions in workplaces where there are carcinogenic substances is also important. Workers employed in such industries must undergo systematic medical examinations.

• There are three main types of skin cancer: basal cell carcinoma, squamous cell carcinoma (non-melanoma skin cancer), and melanoma.
• Skin cancer is the most common form of cancer in humans. Ultraviolet light and solar radiation are the leading cause of skin cancer.
• The most common early sign of skin cancer is a change in the appearance of the skin, such as lumps or sores that are difficult to treat. Such unexplained changes in the appearance of the skin and the absence of any treatment results lasting more than two weeks should definitely be consulted with a dermatologist.
• Non-melonoma skin cancer usually responds well to treatment, unless of course it is detected in an advanced and advanced stage of skin cancer.
• Treatment for nonmelanoma skin cancer depends on the type and location of the growth, the risk of scarring, and the patient's age and health. In its treatment, methods such as curettage and desiccation, surgical excision, cryosurgery, radioactive exposure and Mohs micrographic surgery are used.
• Sun protection and abstinence for sun-sensitive individuals is the best way to prevent the development of all types of skin cancer. Regular follow-up with a dermatologist, especially if there is a predisposition, as well as regular self-examination are good tools for reducing risks. Patients who have previously been diagnosed with any form of skin cancer should undergo regular medical examinations.

Introduction

Skin cancer is the most common form of cancer in humans. It is estimated that more than 2 million new cases are diagnosed each year. At the same time, the growth rate of all forms of skin cancer is increasing from year to year, causing serious concern among dermatologists and oncologists. Thus, American doctors have calculated that almost half of all Americans who live to be 65 years old may develop skin cancer at least once in their lives.

The most common early symptom skin cancer is a change in the appearance of the skin, the appearance of ulcers, age spots or neoplasms that are difficult to treat.

The term "skin cancer" is usually applied to three different conditions:

• basal cell carcinoma (or basal cell epithelioma, basal cell carcinoma)
• squamous cell carcinoma (squamous epithelioma, photosensitive keratosis, spinalioma)
• melanoma

Fig. 1 Differences between different types of skin cancer

The two most common forms of skin cancer are basal cell carcinoma and squamous cell carcinoma. Both of these types are also referred to as non-melanoma skin cancer. Melanoma is the most serious form of skin cancer because it tends to spread (metastasize) throughout the body very quickly. Skin cancer is also known as skin neoplasms.
In this article, we will discuss two types of non-melanoma skin cancer.

Fig.2 Basal cell and squamous cell skin cancer (photo)

Basal cell carcinoma

What is basal cell carcinoma?

Basal cell carcinoma is the most common form of skin cancer. This type of cancer rarely spreads (metastasizes) to other parts of the body. However, it can cause skin damage by germinating and invading surrounding tissue.

What are the known risk factors for developing basal cell skin cancer?

Light skin, sun exposure and age are key factors in the development of basal cell carcinoma. In the population, people with fair skin and advanced age are more likely to have basal cell carcinoma. Most typical place detection of basal cell carcinomas is the face. But it also happens that this type of skin cancer can form in areas of the body that are practically not exposed to sunlight, such as the chest, back, arms, legs and head. A general weakening of the immune system, such as due to illness or medications, may also increase the risk of developing basal cell carcinoma. Other risk factors include:

• sun exposure: There is evidence that, unlike squamous cell carcinoma, basal cell carcinoma can form as a result of occasional, rather than chronic, sun exposure, such as occurring during vacations or vacations, especially at an early age. According to the US National Institutes of Health, ultraviolet (UV) radiation from the sun is the leading cause of skin cancer. The risk of developing skin cancer is also affected by where a person lives. People who live in areas with high levels of UV radiation from the sun are more likely to develop skin cancer. In the United States, for example, skin cancer is more common in southern states such as Texas, where skin cancer is more common than in Minnesota, where the sun and therefore ultraviolet radiation are not as powerful. When comparing countries around the world, the highest prevalence of skin cancer occurs in South Africa and Australia, areas receiving greater amounts of ultraviolet radiation.
• age: Most skin cancers appear after age 50, but harmful effects sun damage begins at an early age. Therefore, it is better for parents to think about protection in order to prevent skin cancer at a later age.
• exposure to ultraviolet radiation in a solarium: Solariums are very popular, especially among young girls and people, and they are available to people who are rarely exposed to solar radiation or who live in cold climates.
• therapeutic radiation: types of radiation used to treat other forms of cancer.

What does basal cell carcinoma look like?

In the initial stages, basal cell carcinoma appears as a small, dome-shaped protrusion and is often covered by a network of small, superficial blood vessels called telangiectasia. Visually, carcinoma tissue appears shiny and translucent, which is why it is referred to as a “pearl” formation. It is often difficult to distinguish basal cell carcinoma from a benign flesh-colored neoplasm without a biopsy. Some basal cell carcinomas contain the pigment melanin, causing them to appear dark rather than shiny as described above.
Superficial basal cell carcinomas often appear on the chest or back and look more like patches of “wet” or dry skin. As a rule, basal cell carcinomas grow slowly over several months or even years.

It takes at least a year for a tumor of significant size to form. Although spreading to other parts of the body (metastasis) is uncommon for basal cell carcinoma, its growth into tissue can cause damage and disfiguring changes to the eyes, ears, or nose if the tumor grows nearby.

How is basal cell carcinoma diagnosed?

Diagnosing skin cancer is usually straightforward. For accurate diagnosis It may be sufficient to remove part or all of the tumor and examine its tissue under a microscope. This procedure is called a biopsy. The biopsy is usually performed under local anesthesia, when the sampling site around the tumor is first injected with an anesthetic and a small piece of skin is cut off with a scalpel or a special device. This method is called thin-section biopsy.

Fig.3 Thin section skin biopsy (Punch biopsy)

How is basal cell skin cancer treated?

There are a large number of methods for treating basal cell skin cancer with a good chance of recovery. The main goal of the oncologist is to remove or destroy the cancer completely while leaving a scar as small as possible. To determine the optimal treatment tactics for each patient, the oncologist determines everything possible factors risk: location and size of skin cancer, scarring risks and the person's age, general health and medical history.

The following methods of treatment for basal cell carcinoma are usually used:

• Drying and curettage: Dermatologists often prefer this method of treatment, in which the basal cell carcinoma is “dried out” and “scraped out” using a special spoon called a curette. The tumor is dried using electric current low power, which allows you to stop possible bleeding and kill remaining cancer cells. In this case, the skin heals without scar formation. This method is best suited for small tumors in aesthetically unimportant anatomical areas such as the trunk and extremities.
• Surgical excision: the tumor is cut out along with the surrounding healthy tissue and a skin suture is applied.
• Radiation therapy: Dermatologists often use radiation therapy for skin cancer, especially in anatomical areas that are difficult to access with surgical correction. A course of 25-30 treatment sessions can achieve a good cosmetic result.
• Cryosurgery: Some dermatologists or oncologists who have received special training in this treatment technique in this technique receive good results in the treatment of basal cell carcinoma using the freezing method. Typically, liquid nitrogen is used to remove a tumor, which damages the abnormal cancer cells and causes them to die.
• Mohs micrographic surgery: The method is so named after its discoverer, Dr. Frederic Moosa, who developed a layer-by-layer technique for removing skin cancer. This technique is also called microscopically controlled ablation. During the operation, the surgeon carefully removes small pieces of the tumor layer by layer and examines them under a microscope immediately during the operation. He performs this procedure until the resulting tissue sample contains no basal cell carcinoma cells. The probability of getting rid of skin cancer using this technique reaches 98%. Mohs micrographic surgery is preferred for the removal of basal cell carcinomas large sizes, or basal cell carcinomas that recur after other treatment methods or with lesions of those parts of the body in which relapse occurs very often. Such anatomical areas are the scalp, forehead, ears and corners of the nose. In cases where large volumes of tissue need to be removed, Mohs micrographic surgery is used in addition to plastic surgery for adequate replacement of skin defects and achieving the best postoperative aesthetic appearance.
• Drug therapy using creams that damage cancer cells (5-FU, Efudex, Fluoroplex) or stimulate the immune system (Imiquimod [Aldara]). They are applied several times a week for several weeks. When applied to the skin, they cause inflammation and irritation of tumor tissue. The advantage of this method is that it avoids the need for surgery, allows the patient to perform the treatment at home, and can provide good cosmetic results. Disadvantages include discomfort, which can vary from mild to severe, and more low frequency complete cure, making this treatment option unsuitable for most types of facial skin cancer.
• For advanced forms of basal cell carcinoma that cannot be treated with surgery or radiation therapy, as well as in rare cases of metastatic basal cell skin cancer, has been approved for use new oral chemotherapy drug- Vismodegib (Erivedge). Despite the fact that this drug is not true medicine, it is quite effective in reducing tumor size when used for many months.

Fig.4 Mohs microsurgery

How can you prevent the development of basal cell skin cancer?

Protection from solar radiation is perhaps the most effective measure for the prevention of all types of skin cancer, especially in individuals susceptible to sun exposure. Regular monitoring and surveillance of people at risk, as well as frequent self-examinations and regular examinations by a dermatologist, are good measures to help identify skin cancer at an early stage. Patients who have already been treated for skin cancer should be closely monitored dispensary observation from an oncologist and a dermatologist.

Sunscreen should be applied liberally and regularly every two to three hours, especially after swimming or physical activity, as it promotes sweating, which weakens the sun protection properties of most moisture-resistant tanning products.

Squamous cell carcinoma

What is squamous cell carcinoma?

Squamous cell carcinoma is a form of cancer that forms from squamous cells, which are thin, flat skin cells. Under a microscope they look like fish scales.

Squamous cells are found in the tissues lining the surface of the skin, the mucous membranes of hollow organs and the lumen of the respiratory and digestive systems. Thus, squamous cell carcinoma can actually arise in any of these organs.
Squamous cell skin cancer is about as common as basal cell carcinoma. Light skin and prolonged sun exposure are leading predisposing risk factors for the development of this form of skin cancer, as opposed to basal cell carcinoma. Men get squamous cell skin cancer more often than women. Also, such nuances as the model of clothing worn and hairstyle play an important role in the development of this form of skin cancer. For example, women with long hair that covers their ears are significantly less likely to develop squamous cell carcinoma of the ears than men or women with open-ear hairstyles.

A condition called actinic (or solar) keratosis is a precancerous condition. In 10% of cases, this skin disease can transform into squamous cell carcinoma. This type of keratosis is a kind of marker indicating the possibility of a risk of developing any type of cancer. Keratoses appear on the skin of the body as rough, red bumps on the head, face, ears, and back of the hands. They often appear against mottled, sun-damaged skin. In most cases, keratosis can become widespread and cause deformation of the skin. When photosensitive keratosis (also known as solar keratosis) becomes thicker and more painful, there should be concern because when such symptoms appear, transformation into squamous cell carcinoma is possible.

A rapidly growing form of squamous cell carcinoma in which a crater-shaped depression forms in the center of the tumor is called keratoacanthoma. Despite the fact that some dermatologists consider this disease not to be a true cancer, it requires special attention, since most pathologists and histologists consider keratoacanthoma to be a form of squamous cell carcinoma that requires radical treatment.

Other skin diseases that predispose to the development of squamous cell carcinoma are:

• Actinic cheilitis, a condition in which a chronic inflammation, which is a consequence of direct exposure to sunlight, as a result of which the boundaries between the surrounding skin and the lip are blurred;
• Bowen's disease, sometimes referred to as squamous cell carcinoma "in situ". (This means that cancer forms locally in the superficial layers of the epidermis, without involving deeper layers). Bowen's disease appears as scaly patches on exposed parts of the torso and limbs;
• Bowenoid papulosis: These are genital warts whose cells under a microscope look similar to the cells found in Bowen's disease, but behave like warts rather than cancer.

What risk factors lead to the development of squamous cell carcinoma?

The most important risk factor for developing squamous cell carcinoma is sun. In most cases, the growths develop from precancerous spots called radial or solar keratoses. Typically, these formations form over many years of sun damage on parts of the body such as the forehead and cheeks, as well as the back of the hands.
Several unusual predisposing factors for squamous cell carcinoma are also known. These include exposure to arsenic, hydrocarbons, heat or x-rays. In some cases, squamous cell carcinoma forms from scar tissue. Suppression of the immune system by infection or drugs may also contribute to the appearance of neoplasms. Some strains of the human papillomavirus (HPV), which is responsible for the appearance of genital warts, can contribute to the development of squamous cell carcinoma of the anogenital area.

Does squamous cell skin cancer tend to spread (metastasize)?

Yes. Unlike basal cell carcinoma, squamous cell carcinoma can metastasize or spread to other parts of the body. These tumors usually form as a proliferation of flesh-colored or red nodules. Squamous cell carcinoma that develops as a result of solar keratoses or sunburn of the skin is always easier to treat and less likely to metastasize than cancer that develops from traumatic or radiation scars. Squamous cell carcinoma that forms on the lower lip has the highest tendency to metastasize. That is why correct and timely diagnosis of any neoplasm that forms in a given place is especially important.

How is squamous cell carcinoma diagnosed?

As with basal cell carcinoma, for staging correct diagnosis a biopsy is used. For this form of skin cancer, a puncture version of tissue biopsy is used, when the skin around the formation is pricked with an anesthetic (numbed) and a piece of tissue is cut off using a special device for examination under a microscope to identify atypical cancer cells.

How is squamous cell skin cancer treated?

Treatment methods for squamous cell carcinoma are identical to those used to treat basal cell carcinoma (the principles of each have been described previously). Below are the main ones:

• Drying and curettage
• Surgical excision
• Radiation therapy
• Cryosurgery
• Mohs micrographic surgery
• Drug therapy using drugs that kill cancer cells (5-fluorouracil - 5-FU, Efudex, Fluoroplex) or stimulate the immune system (Aldara).

Fig.5 Laser equipment for the treatment of skin cancer

How can squamous cell carcinoma be prevented?

Even more than in the case of basal cell carcinoma The main way to prevent squamous cell carcinoma is to minimize sun exposure and have regular checkups with a dermatologist.

Among preventive measures the following can be distinguished:

• limiting sun exposure;
• Avoid unprotected sun exposure during peak hours (midday);
• Wear wide-brimmed hats and tightly woven protective clothing when outdoors in the sun;
• regularly use waterproof or water-resistant sunscreen with UVA protection and SPF 30 or higher;
• undergo regular checks and examination of any suspicious area of ​​skin, and also inform the dermatologist about any changes that occur; And
• Avoid using tanning beds and use sunscreen with SPF 30 and UV protection. Many people go to the solarium on the eve of a vacation, assuming that artificial tanning allows them to create a “base layer” that prevents the damaging effects of the sun. Even for those with little sun exposure, such as people with dark skin, it is recommended to use at least SPF 6, while the desired SPF level is 30 or higher.

Sunscreen should be applied generously and regularly every two to three hours, especially after swimming or physical activity, as this promotes sweating, which weakens the sun protection properties of most waterproof sunscreens.

How is skin cancer treatment performed?

Skin cancer has good forecasts and the results of its treatment are much superior to those of other forms of cancer. Skin cancer is mostly curable. Although most skin cancers are treatable and can be cured completely, patients who undergo treatment always have a higher risk of developing it again than the average risk of developing a new skin cancer. This is a prerequisite for regular dynamic observation and following the recommendations of your dermatologist or oncologist will significantly reduce your risk of developing skin cancer again.

How does vitamin D affect the incidence of skin cancer?

Some recent research suggests that the body's production of vitamin D when exposed to sunlight may prevent the occurrence and spread of cancer, both internal and skin cancer. Despite much controversy surrounding these studies, this statement is not without common sense, since vitamin D is actively involved in the process of normal reproduction and differentiation of young cells. Typically, dermatologists recommend sunbathing to produce vitamin D, while limiting sun exposure to a maximum of 15 minutes several times a week. For most people, this type of sun exposure is not expected to result in a significantly higher risk of developing skin cancer. Currently, no competent organization dealing with this problem suggests the need for visits to a solarium or natural tanning for the natural production of vitamin D, since it is now available in tablet form. When taken orally in large doses, vitamin D can cause health problems, so its use should be monitored by a doctor.

Skin cancer, like most oncological diseases, is considered a polyetiological condition. And it is not always possible to reliably determine the main trigger for the appearance of malignant cells. At the same time, the pathogenetic role of a number of exo- and endogenous factors has been proven, and several precancerous diseases have been identified.

Skin cancer is a malignant neoplasm in the form of a tumor, which develops as a result of atypical transformation of cells under the influence of subjective and objective factors. The disease is very dangerous because it affects the largest and most important organ human body.

When cancer is detected on early stages and purpose proper treatment, you can get rid of it forever, preventing the return of the disease. In the case of the development of a severe, aggressive form, other organs of the human body are often affected, which leads to irreversible consequences, and sometimes even death.

It is extremely important to promptly detect any kind of changes in the skin and consult a doctor for examination and treatment.

Skin cancer is a fairly common form of a malignant type of tumor, in which both women and men are affected almost equally, their age is generally from 50 years or more, although the possibility of the disease developing in one or another variety of forms in more than young patients.

The affected area is, as a rule, areas of the skin that are open to one or another influence. The development of skin cancer is observed in 5% of the total number of cases of cancer as such.

Mechanism of disease development

Impact of UV and other causal factors leads in most cases to direct damage to skin cells. In this case, it is not the destruction that is pathogenetically important cell membranes, but the effect on DNA.

Partial destruction of nucleic acids causes mutations, which leads to secondary changes in membrane lipids and key protein molecules. Predominantly basal epithelial cells are affected.

Various types of radiation and HPV have not only a mutagenic effect. They contribute to the appearance of relative immune deficiency.

This is explained by the disappearance of dermal Langerhans cells and the irreversible destruction of some membrane antigens that normally activate lymphocytes. As a result, the functioning of the cellular immune system is disrupted and protective antitumor mechanisms are suppressed.

Immunodeficiency is combined with increased production of certain cytokines, which only worsens the situation. After all, these substances are responsible for cell apoptosis and regulate the processes of differentiation and proliferation.

The pathogenesis of melanoma has its own characteristics. The malignant degeneration of melanocytes is promoted not only by exposure to ultraviolet radiation, but also by hormonal changes.

Clinically significant for disruption of melanogenesis processes are changes in the levels of estrogens, androgens and melanostimulating hormone. This is why melanomas are more common in women of reproductive age.

Moreover, hormone replacement therapy, taking contraceptive drugs and pregnancy can act as a provoking factor for them.

Another important factor in the appearance of melanomas is mechanical damage to existing nevi. For example, tissue malignancy often begins after the removal of a mole, accidental injury, and also in places where the skin is rubbed by the edges of clothing.

A malignant neoplasm begins with one or more pinkish spots that begin to peel off over time. This initial stage can last from one or two weeks to several years.

The main localization is the front part, the dorsal shoulder region and the chest. This is where the skin is most delicate and susceptible to physiological changes in organism.

Skin cancer can form in the form of pigment spots that grow in size, become convex, and sharply darken to a dark brown color. Often occurs when moles degenerate into malignant neoplasms.

The tumor may also look like a simple wart.

CAUSES

Before the formation of a full-fledged malignant tumor, precancerous formations often appear, that is, precancerous diseases that have a high tendency to malignancy.

Precancers are divided into obligate and facultative. Obligate tumors degenerate into a malignant neoplasm in almost 100% of cases. This type of tumor includes:

• Bowen's disease;
• Erythroplakia of Keira;
• Xeroderma pigmentosum;
• Paget's disease.

The development of Bowen's disease is most common in older men. Precancer of this type is characterized by a violation of the integrity of the skin in any part of the body, however, it was noted that the surface of the body is more often affected.

When examining the skin, a solitary plaque is detected, growing up to 10 cm in diameter. The hue varies in color from pale pink to purple.

The boundaries of the tumor are clear, moderately rising above the surface of the skin. During development, the surface of the formation may become crusted and eroded.

Bowen's disease is characterized by slow growth and a 100% chance of degeneration into squamous cell carcinoma. Exists increased risk combinations of skin lesions and cancer of internal organs.

A peculiar variation of Bowen's disease is Keir's erythroplakia, the only difference is the predominant damage to the mucous membranes. Compared to other tumors, it is considered a rare disease.

Upon visual examination, it appears as a single plaque, having a scarlet tint with clear boundaries and edges rising above the surface of the skin. An essential feature, pointing to malignant degeneration, is a change in the clarity of the boundaries, the appearance of erosion and ulceration.

In Keir's erythroplakia, the ulcer is covered with fibrin or a hemorrhagic crust.

Xeroderma pigmentosum is a disease that manifests itself in childhood. It is characterized by hereditary transmission in an autosomal recessive manner. Xeroderma pigmentosum manifests itself as hypersensitivity to direct sunlight. Researchers have identified three main periods of the disease:

• Erythema and hyperpigmentation;
• Atrophic stage with the appearance of telangiectasia;
• Stage of neoplasms.

The exact reasons for the development of skin cancer cannot be established, but experts name a number of prerequisites that can provoke the disease:

• Exposure of the skin to carcinogenic chemical elements.
• Ionizing radiation.
• Frequent exposure of the skin to ultraviolet rays.
• Mechanical damage to tissues, scar formation, which in the future can cause the formation of cancer cells and the development of oncology.
• A burn or radiation dermatitis can trigger the development of cancer.
• Degeneration of moles into malignant tumors.
• Heredity.
• The presence of precancerous diseases: nevi, skin pigmentation, skin ulcers, syphilis, tuberculosis, melanosis, etc. In case of incorrect or untimely treatment These diseases can lead to skin cancer.

Causes are a condition or situation that is fertile ground for the development of a particular disease.

The causes of skin cancer are:

• influence of direct ultraviolet and ionizing radiation;
• long-term exposure to chemical carcinogens on the skin surface, such as tobacco smoke;
• genetic predisposition of an organism to cancer diseases, in particular to skin cancer;
• prolonged thermal effects on any area of ​​the skin;
• occupational hazards, for example, many years of work associated with skin contact with arsenic and tar;
• various skin diseases related to precancerous conditions, for example, chronic dermatitis, keratoacanthoma, senile dyskeratosis, a large number of warts, atheromas and papillomas, which are often injured;
• scars left after illnesses, for example, lupus, syphilis, trophic ulcers or burns.

The causes of skin cancer can be divided into external and internal.

External reasons

There are many predisposing factors that can cause skin cancer.

• Excessive exposure to solar radiation and ultraviolet radiation. This factor is especially dangerous for fair-skinned and fair-haired people.
• Professions that involve long stay in the sun.
• Chemical carcinogens (fuel oil, arsenic, oil and others).
• Long-term thermal effects on specific areas of the skin. An example is “kangri cancer”, it is common among people in the mountainous regions of Nepal and India. This type of cancer develops on the skin of the abdomen, in those areas where pots of hot coal are placed to warm up.
• Precancerous skin diseases (Bowen's disease, Paget's disease, xeroderma pigmentosum, Queyra's erythroplasia and benign neoplasms who are subject to constant trauma).

The following causes of skin cancer can also be identified:

• Smoking.
• Contact radiation and chemotherapy. These methods, which were used to treat cancer of other localizations, can also cause skin cancer.
• Reduced immunity due to the influence of various factors. These factors may be: AIDS, use of immunosuppressants and glucocorticoids after organ transplantation and in the treatment of autoimmune diseases.
• Genetic predisposition.
• Sexual characteristics. For example, melanomas, which occur mainly in women.

When considering the reasons that provoke the development of skin cancer, there are two main types of factors that are directly related to the process. In particular, these are exogenous factors, as well as endogenous factors; let’s consider them in a little more detail.

Otherwise they can be defined as external factors. The most important of these factors is ultraviolet radiation and sunlight in particular.

What is noteworthy is that the development of squamous cell and basal cell cancer is ensured by chronic damage to the skin resulting from exposure to UV radiation, but the development of melanoma occurs primarily as a result of periodic intense exposure to sunlight.

Moreover, in the latter version, even a single exposure is sufficient for this.

There are several predisposing reasons contributing to the appearance of malignant skin tumors, namely:

1. Long-term irradiation of the skin with UV rays. Proof of this can be the fact that residents of the southern regions suffer from skin cancer much more often than the northern ones.
2. Exposure of skin to radiation.
3. Long-term thermal effects on the skin.
4. Chemical exposure. For example, contact with soot, various resins, tar, arsenic.
5. Hereditary predisposition to skin cancer.
6. Frequent use of medications that suppress the immune system (antitumor drugs, corticosteroids.
7. Age over 50 years. At a younger age, malignant skin diseases appear less frequently, and skin cancer in children is diagnosed even less frequently (0.3% of all cancers).
8. Mechanical injuries of nevi, birthmarks, scars.

Why does skin cancer appear?

In addition to the above causes of skin cancer, there are also a number of diseases considered precancerous. Precancerous diseases are divided into obligate and facultative precancer. Obligate precancer, as a rule, is a rare, slowly developing disease, which, however, completely turns into cancer. These include:

• xeroderma pigmentosum
• Paget's disease
• Bowen's disease
• Keir's erythroplasia

Facultative precancers include all kinds of chronic skin diseases: dermatitis, inflammatory and dystrophic processes. Slow-healing wounds and ulcers on the skin are also considered an optional precancer.

Skin cancer, symptoms and signs of different forms have significant differences

Signs of skin cancer to watch out for

• the presence of new moles or spots on the surface of the skin;
• dark red growths that rise above the surface of the skin;
• wound surfaces that do not heal for a long time;
• moles that have been present on the body for a long time began to change shape, color and size.

How does skin cancer manifest in each individual form?

CLASSIFICATION

There are several classifications according to which types of skin cancer can be distinguished. According to histological characteristics:

1. Basal cell carcinoma or basal cell carcinoma is the most common type of skin malignancy. A more favorable type of cancer, because there is no tendency to infiltrative growth and metastasis;
2. Squamous cell carcinoma is often formed against the background of existing precancerous skin diseases. The oncological process is prone to germination of the skin thickness and early elimination of metastases.

There is no classification by localization as such. Cancer can affect almost the entire skin, including the skin of the lips, external genitalia, scrotum, and anus.

The TNM classification includes four stages of skin cancer development, depending on the size of the tumor node, damage to regional nodes, and the presence of distant metastases.

Skin adenocarcinoma

Most often, skin cancer refers to all non-melanoma malignant neoplasms that originate from various layers of the dermis. Their classification is based on their histological structure. Melanoma (melanoblastoma) is often considered an almost independent form of carcinodermatosis, which is explained by the peculiarity of its origin and very high malignancy.

The main types of non-melanoma skin cancer are:

• Basal cell carcinoma (basal cell carcinoma) is a tumor whose cells originate from the basal layer of the skin. Can be differentiated or undifferentiated.
• Squamous cell carcinoma (epithelioma, spinalioma) - occurs from the more superficial layers of the epidermis. It is divided into keratinizing and non-keratinizing forms.
• Tumors arising from skin appendages (adenocarcinoma sweat glands, adenocarcinoma of the sebaceous glands, carcinoma of the appendages and hair follicles).
• Sarcoma, whose cells are of connective tissue origin.

When diagnosing each type of cancer, the WHO recommended clinical classification TNM. It allows you to encode various characteristics of the tumor using digital and alphabetic notations: its size and degree of invasion into surrounding tissues, signs of regional damage lymph nodes and the presence of distant metastases. All this determines the stages of skin cancer.

Each type cancerous tumor have their own growth characteristics, which are additionally reflected when making the final diagnosis. For example, basalioma can be tumoral (large and small nodular), ulcerative (in the form of a perforating or corrosive ulcer) and superficial transitional.

Squamous cell carcinoma can also grow exophytically with the formation of papillary outgrowths or endophytically, that is, as an ulcerative-infiltrative tumor. Melanoma can be nodular or non-nodular (superficially widespread).

Other types of skin cancer are much less common and account for a fraction of a percent of all skin cancers. These can be tumors of the sweat and sebaceous glands (adenocarcinoma), tumors from the tissues that make up the follicles, metastases in the skin from other neoplasms.

The type of tumor in these cases can only be determined using diagnostic procedures - MRI, computed tomography and biopsies.

Adenocarcinoma

Adenocarcinoma is a fairly rare type of skin cancer. Develops from glandular cells (sweat and sebaceous glands), grows slowly. It looks like a dense blue-violet nodule or a papule rising above the skin, formed in the armpit, groin, under mammary glands among women.

The node is characterized by slow growth, but in some cases it can reach large sizes (8-10 cm). Germination deeper beyond the skin tissue and metastasis are rare. After removal, the tumor may recur in the same place.

Verrucous carcinoma

Verrucous carcinoma is a rare type of skin cancer, a type of squamous cell carcinoma. Appears on the skin of the hands appearance resembles a wart, which makes correct diagnosis difficult in the early stages of the disease. However, these formations can bleed, which allows you to pay attention to them in time.

Since the skin is made up of cells that belong to a large number tissues, there are significant differences in the tumors that affect them. Therefore, the concept of cancer in this case is very collective in nature and defines all pathologies of a malignant nature.

However, experts identify the most common types, which include basilomas, melanomas, squamous cell formations, lymphomas, carcinomas and Kaposi's sarcoma.

Squamous cell skin cancer

This type of pathological process on the skin has several synonyms; it can also be called squamous cell epithelioma or spinalioma. It occurs regardless of the area of ​​the body and can be located anywhere.

But the exposed parts of the body, as well as the lower lip, are most susceptible to this damage. Sometimes doctors discover squamous cell carcinoma localized on the genitals.

This tumor is not gender-selective, but as for age, pensioners are more often affected. Experts point to scarring of tissue after burns or mechanical damage that is systematic in nature as the reasons that provoke its appearance.

Actinic keratosis, chronic dermatitis, lichen, tuberculous lupus and other diseases can also provoke the appearance of squamous cell carcinoma.

Basalioma or basal cell skin cancer.

It got its name from the place where it “grows” - the basal layer of the epidermis. This tumor lacks the ability to metastasize and recur. Its migration is directed mainly into the depths of tissues with their inevitable destruction.

About 8 out of 10 all cases of skin cancer are of this type.

This is the least dangerous of all types of skin tumors. The exception is those cases when basal cell carcinoma is located on the face or ears: In such circumstances it can reach impressive volumes, affecting the nose, eyes, and damaging the brain. Most often found in older people.