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Precancerous conditions and malignant tumors of the epidermis.

Precancerous conditions of the skin - actinic keratosis, cutaneous horn, Bowen's disease, Keir erythroplasia.

Actinic keratosis. Almost always, before malignancy in the epidermis, dysplastic changes appear, similar to changes in other organs lined with stratified squamous epithelium, for example, in the cervix. Since dysplastic changes are often the result of chronic exposure to sunlight, they are called actinic (photochemically active) keratosis. Photochemical skin lesions by solar radiation are especially common in people with fair skin. Similar changes are caused by ionizing radiation, some hydrocarbon compounds and arsenic. Skin lesions are usually less than 1 cm in diameter. Their color varies from tan to red or flesh, and the consistency is very rough (like sandpaper). In some of these lesions, so much keratin is produced that skin horn occurs (see below). Most often exposed skin areas are affected: the face, forearms and the back of the hands. The same lesions sometimes occur on the lips (actinic cheilitis).

With actinic keratosis, cellular atypia is noted mainly in the lower layers of the epidermis. It can be associated with hyperplasia of the cells of the basal layer or, conversely, with early atrophy, leading to a diffuse decrease in the thickness of the epidermis in the neoplasm. Atypical basal cells, as a rule, have signs of dyskeratosis, as well as pink or reddish cytoplasm. The dermis contains thickened elastic fibers (dermis elastosis), which is regarded as a possible violation of the production of elastic fibers damaged by solar radiation fibroblasts. Thickening of the stratum corneum is noted, in contrast to normal skin, the nuclei in the cells of this layer are preserved. The nature of actinic keratosis is unknown. It is very likely that many such skin changes regress or remain stable throughout life. However, a large number of them are malignant, which justifies surgical excision.

Skin horn (acrochordon, keratoma horn) is a squamous benign skin tumor in the form of a conical or linear dark mass, consisting of dense horn masses. It often occurs in open areas of the body. Microscopically, at the base of the horny masses, acanthotic growths of the epidermis are expressed, in the underlying dermis is a thick lymphohistiocytic infiltrate

Bowen's disease is characterized by the fact that changes are localized everywhere, more often on the skin of the genitals, eyelids and trunk. It is regarded as intraepithelial (intraepidermal) squamous cell carcinoma (carcinoma in situ) and is a clearly defined red scaly plaque, possibly ulcerating. Hyper- and parakeratosis, acanthosis are microscopically characteristic, multinucleated giant cells, large ovoid cells (pagetov), ​​atypical mitoses are found. Intercellular bridges are preserved. In the underlying dermis, pronounced lymphohistiocytic infiltrate. With prolonged existence, invasive growth is possible with the development of poorly differentiated epidermoid cancer.

Keir erythroplasia, like Bowen's disease, is considered as intraepithelial cancer. Thinning of the granular and horny layers of the epidermis, the presence of acanthotic cords deeply penetrating into the tissue, represented by polymorphic cells with a small number of mitoses, are microscopically characteristic. Around acanthosis, abundant lymphoplasmacytic infiltration is observed against the background of a sharp expansion of blood vessels.

Squamous cell carcinoma of the skin. In older people, squamous cell carcinoma is the most common tumor among those that occur in exposed areas of the skin. This neoplasm is more common in men. In addition to solar radiation, factors predisposing to malignancy are: industrial carcinogens (contained, in particular, in resins and oils); chronic skin ulcers; draining osteomyelitis with the presence of skin fistulas; scars after burns; skin absorption of arsenic compounds; exposure to ionizing radiation. People with xeroderma pigmentosa and immunocompromised individuals are at higher than healthy risk of squamous cell skin cancer.

The generally recognized exogenous cause of squamous cell carcinoma of the skin is the exposure of the ultraviolet part of solar radiation to keratinocytes with damage to their DNA. Sunlight, apparently, also has a direct immunosuppressive effect on the skin, disrupts the normal control function of antigen-presenting process Langerhans cells. DNA sequences of certain viruses (e.g., human papillomavirus HPV36) have recently been found in DNA extracted from potential squamous cell progenitor cells.
Thus, chronic viral infection can contribute to the occurrence of skin neoplasms. Finally, some chemical agents have a direct mutagenic effect, which is realized by generating DNA adducts with subsequent activation of oncogenes.

Invasive skin cancer is accompanied by keratinization to varying degrees and may be ulcerated. Histologically, squamous cell carcinoma is characterized by strata of atypical polymorphic epithelium, and the extracellular bridges are preserved. Cancer is isolated with keratinization or without keratinization, spindle cell cancer, clear cell cancer of the adenoid type (with structures resembling glands).

Skin cancer is characterized by varying degrees of histological differentiation and stages according to the TNM system (Table 37.11).

Only about 5% of cases of invasive skin cancer are accompanied by metastases to the regional lymph nodes, with tumor progression, the cancer metastases through the lymphogenous and hematogenous pathways.

Basal cell carcinoma (basal cell carcinoma) is the most common skin tumor. It has pronounced infiltrating growth, often recurs, but usually does not give metastases, therefore it is more correct to include it in the group of tumors with locally destructive growth. Basically, it appears in those places that are constantly exposed to solar radiation (face and neck), it is multiple. It occurs with the same frequency in people of both sexes, mainly in the elderly. The incidence of basal cell skin cancer increases sharply in individuals with reduced immunity (for example, after immunosuppressive therapy) and in the presence of defects in DNA repair.

The neoplasm is represented by a plaque with a pearl shade, sometimes pigmented. The tumor can ulcerate with the formation of an extensive deep ulcer (ulcus rodens - ulcer with superficial erosion). Microscopically characteristic polymorphic

Table 37.11. Stages of spread of squamous skin cancer in the TNM system.

T1 - a tumor with a diameter of up to 2 cm has exophytic and superficial growth
T2 - a cancerous node with a diameter of 2-5 cm grows in the dermis
TK - neoplasm more than 5 cm in diameter or deeply growing in the dermis
T4 - the tumor grows into the underlying tissues (muscles, cartilage or bone)
N1 - on the side of the primary cancerous node, metastases in regional lymph nodes are detected, which are displaced upon palpation
N2 - palpatory metastases in the lymph nodes are determined either only on the side opposite to the location of the tumor, or on both sides
N3 - non-biased metastases are detected in regional lymph nodes on both sides with respect to the primary cancerous node
M1 - there are distant (hematogenous) metastases
cords and complexes of small intensely stained cells resembling cells of the basal layer of the epidermis, having a prismatic along the periphery of the cords, and a polygonal shape in its thickness. There are mitoses. In typical cases, the phenomenon of "accumulation", i.e. clusters and strands of tumor cells “slide” from the basal layers of the epithelium, like drops penetrating the dermis.

There are superficial multicentric types of basal cell carcinoma (characterized by multiple cell strands growing into the dermis), scleroderma-like (with sclerosis and stromal hyalinosis), fibroepithelial types, and basal cell carcinoma: adenoid, characterized by the formation of glandular and cystic structures; mucous; pigmented; trichobazalioma (contains piloid or hair-like) structures; basal squamous cell carcinoma.

Cancer from tactile cells (Merkel cells). This rare tumor comes from small epidermal mechanoreceptors, which are derivatives of the neural crest and are called tactile (tactile) cells (Merkel cells). Cancer from Merkel cells is a very malignant neoplasm, localized more often in the head and neck and gives early distant metastases. The neoplasm parenchyma consists of complexes of small round cells containing cytoplasmic granules of the neurosecretory type. This primary epidermal tumor may resemble metastatic small cell lung carcinoma or some lymphomas that occur with lesions of the dermis.

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Precancerous conditions and malignant tumors of the epidermis.

  1. Precancerous conditions and malignant tumors of the epidermis
    Actinic keratosis. Almost always, before malignancy, dysplastic changes appear in the epidermis; there is an analogy with the stages of development of squamous cervical cancer. Since dysplastic changes are often the result of chronic exposure to sunlight and are associated with the formation of excess keratin, foci of dysplasia are called actinic (photochemically
  3. Background and precancerous conditions
    Most malignant ovarian tumors develop against the background of previous benign tumors. Therefore, all true benign ovarian tumors should be considered as precancerous conditions. Ovarian tumors more often develop in women with a certain premorbid background. Women with this background should be classified as a risk group for the development of ovarian tumors (background conditions).
  4. Precancerous conditions
    The precancerous conditions of the cervix (dysplasia) is a pronounced proliferation of the atypical epithelium of the cervix with a violation of its “stratification” (stratification) without involving the stroma and surface epithelium in the process. Therefore, dysplasia is a histological term recommended by WHO (1976) instead of many other names for this pathology: atypia, cervical intraepithelial neoplasia
  5. Precancerous conditions of the cervix
    Types of precancerous conditions of the cervix: 1) Cervical erosion is a red area on the cervix, clearly delimited from the surrounding pale pink surface, and located around the opening of the cervical canal. There is true and pseudo-erosion. Cervical ectopy is usually not accompanied by any symptoms. Extensive ectopia sometimes causes an increased amount of mucous discharge
  6. Precancerous conditions of the cervix
    Types of precancerous conditions of the cervix: 1) Cervical erosion is a red area on the cervix, clearly delimited from the surrounding pale pink surface, and located around the opening of the cervical canal. There is true and pseudo-erosion. Cervical ectopy is usually not accompanied by any symptoms. Extensive ectopia sometimes causes an increased amount of mucous discharge
  7. Pigmentation disorders. Pathology of the melanocytic system of the epidermis. Melanocytic tumors
    Melanocytes are located in the basal layer of the epidermis. Their number varies in different parts of the skin. Melanocytes synthesize melanin in specialized organelles - melanosomes, tyrosinase is involved in this process. This enzyme catalyzes the conversion of tyrosine to dioxiphenylalanine (DOPA), which is converted into melanin during other biochemical reactions. Melanosomes spread along them,
  8. Malignant tumors
    SARCOM is a malignant tumor from the mesenchymal tissue. Unlike sarcoma cancer, the first metastases are hematogenous. Histogenesis sarcomas are divided into a number of varieties. From fibrous tissue. 1. Fibrosarcoma. 2. Swelling dermatofibroma (malignant histiocytoma) - unlike other sarcomas, it is characterized by slow growth and does not give metastasis for a long time, although it grows
  9. Malignant tumors
    Malignant tumors of the nose and paranasal sinuses take third place in frequency among other malignant lesions of the upper respiratory tract (larynx and pharynx) and, according to published data, comprise 2 - 3% of malignant tumors of all localizations. Malignant tumors most often develop in the maxillary sinus. In second place in frequency are lattice maze tumors.
  10. Malignant Epithelial Tumors
    They are called cancer, or carcinoma. General characteristics. 1. Meet much more often than all other malignant tumors. 2. Often associated with previous diseases and conditions, which are called precancerous. 3. The development of many carcinomas (morphogenesis) is associated with previous changes in the epithelium - hyperplasia, metaplasia, dysplasia. 4. The only precancerous
  11. Malignant tumors
    In the upper respiratory tract, cancer is mainly found in various forms and rarely (about 3% in relation to malignant tumors of the ENT organs)
  12. Malignant pharyngeal tumors
    The comparative incidence of pharyngeal cancers is high; carcinomas, lymphoepitheliomas, cytoblastomas, sarcomas, reticulocytomas, and mixed tumors are found among them. Men get sick more often than women, usually in middle age. K l and n and with to and to kartin and. The early symptoms of pharyngeal malignant tumors are poor and little characteristic. Light sensations may appear.
  13. Malignant tumors of the nose and paranasal sinuses
    Malignant diseases of this localization - cancer and isarcoma, as a rule, are primary. They are relatively rare, more often in middle-aged and elderly men. Most often, the primary malignant process affects the maxillary, then the ethmoid, frontal and sphenoid sinuses. Rarely, the nasal septum is the source of the malignant tumor. Malignancy
  14. Malignant tumors of the ear
    Malignant tumors of the ear can be both primary, i.e. developed directly in a particular department of the ear, and arising from the germination of tumors from neighboring organs and tissues. In the outer and middle ear, cancer is more often diagnosed in adults, and sarcoma in children. Of the other species, there may be melanoma. The course of tumors of the outer ear is relatively slow, they look like
  15. Malignant tumors of the vulva and vagina
    Vulvar cancer (RV) is found mainly in elderly women and accounts for 3-5% of all malignant diseases of the genitals. It develops against the background of involutive dystrophic processes. An important role in the occurrence of this pathology is given to metabolic and endocrine disorders and viral infection. Classification of PB by stages • Stage 0 - pre-invasive carcinoma. • I stage - tumor up to 2
  16. Malignant skin tumors
    There are many theories of cancer (embryonic, virogenogenetic, hereditary, somatic mutations, etc.). Malignant tumors are characterized by infiltrating growth with destruction of the surrounding tissue and metastasis. There are two types of skin cancer: basal cell and squamous. Basal cell carcinoma, or basal cell carcinoma, occurs primarily in the elderly.
  17. Malignant Intestinal Tumors
    - these are pathological proliferation of atypical cells with an autonomous (not always) progressive irreversible nature of growth, which replace and infiltrate normal tissue. Classification of the Stage of cancer Stage 1 - a tumor of small size, localized in the thickness of the mucosa or submucosal layer, without metastases; Stage 2: a) a large tumor, but not more than a semicircle
    Among malignant neoplasms in women, breast cancer is one of the first places. In recent years, the incidence of a combination of pregnancy and cancer has increased. There are two aspects of this problem: cancer among pregnant women and pregnancy with cancer. Breast cancer in pregnant women occurs in 0.03-0.3% of cases, pregnancy with breast cancer - in 0.78-3.8%, and in some reports
  19. Anemia in malignant tumors and their multiple metastases in the bone marrow
    The cause of the anemic condition in malignant tumors may be the following factors: 1) the toxic effect of the malignant tumor on erythropoiesis; 2) bleeding due to decay of the tumor and rupture of blood vessels; 3) secondary joining infection; 4) an erythropoiesis disorder due to bone marrow metastases; 5) achilia (with cancer of the stomach) and the associated violation of assimilation
  20. Malignant tumors of the larynx
    Malignant tumors
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