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Among the cells of the numerous structural components of the dermis that are not related to the appendages of the skin, smooth muscle cells, pericytes, fibroblasts, elements of the nervous tissue and endothelium should be distinguished. All these cells can become sources of tumor growth. To avoid repetition, this section does not contain descriptions of leiomyosarcoma (see chapter 21), neurofibroma (see chapter 26), hemangioendothelioma (see chapter 11), etc. Benign fibrous histiocytoma. It belongs to the group of morphologically and histogenetically related benign skin tumors, consisting of fibroblasts and histiocytes (for malignant fibrous histiocytoma, see chapter 24). This tumor is found in adults, often occurs on the lower extremities of young or older women. As a rule, it is painless. Externally, it is a tan dense papule. The size of this papule may increase slightly over time or, conversely, decrease. Actively growing neoplasms sometimes reach several centimeters in diameter. The property of fibrous histiocytoma to be pressed inward when squeezed from the sides is an important distinguishing feature from the nodular form of melanoma, which, on the contrary, protrudes from the surface of the skin when compressed. The most common form of fibrous histiocytoma is called dermatofibroma. It is built of spindle-shaped fibroblasts forming a tumor conglomerate, which has no capsule and is located in the middle parts of the dermis. Often, tumor fibroblasts spread into the subcutaneous fat. In most cases, a special form of epidermal hyperplasia is noted, which is characterized not only by acanthosis, but also by hyperpigmentation of acanthotic outgrowths. Despite the fact that histiocytes with foamy cytoplasm can also be found in dermatofibroma, these cells are few. Other forms of benign fibrous histiocytoma, in contrast, consist mainly of such foamy histiocytes, alternating with a small number of fibroblasts. They may contain blood vessels and hemosiderin deposits (Fig. 25.15). Such forms are called sclerosing hemangiomas. The histogenesis of fibrotic histiocytes remains unexplained. In many individuals, trauma precedes the neoplasm, therefore an abnormal response to damage is suggested, possibly representing some kind of analogy to the appearance of a large amount of altered collagen in a hypertrophic scar or keloid. Vubuhanmtsaya dermatofibrosarcoma. This highly differentiated primary skin fibrosarcoma grows slowly and, although characterized by local aggressive growth, rarely gives metastases. Externally, a tumor is a dense, clearly defined nodule that usually occurs on the trunk. Often a tumor appears as clusters of protruding nodules inside a dense plaque, which sometimes ulcerates. Microscopically, the tumor tissue is characterized by a highly developed cell population (hypercellularity), which is represented by fibroblasts, often forming vortex shapes (Fig. 25.16). Mitoses are not as numerous as in moderately or low-grade Fig.
(histiocytoma, sclerosing hemangioma) (IAP preparation), fibrosarcoma (see chapter 24). Unlike dermatofibroma (see above), the epidermis usually becomes thinner. Often, tumor invasion into the subcutaneous fatty tissue is noted, which prevents complete surgical removal of it. Xanthima. This is an intradermal tumor-like accumulation of histiocytes having a foamy cytoplasm. Such clusters can appear in some familial (see Chapter 8) or acquired diseases leading to hyperlipidemia with lymphoproliferative malignant neoplasms. Sometimes they also occur in the absence of any underlying disease. By its external signs, the xanthoma is divided into 5 options. Since the identification of these variants may serve as a certain marker of the patient’s hyperlipoproteinemia, for each tumor variant the types of lipid metabolism disorders (types I – V) are determined. Xanthomas with a rash (types 1, IIB, III, IV and V) appear as sudden rashes of yellow papules, which increase or decrease in proportion to the content of triglycerides and lipids in the plasma. They occur on the skin of the buttocks, the back of the thighs, the skin of the knees and elbows. Tuberous (types IIA and III; occasionally IIB and IV) and tendon (types IIA and III; occasionally IIIB) xanthomas appear in the form of yellow nodules, which Fig. 25.16.
You are a swelling dermatofibrosarcoma of the skin
. Visible vortices formed by tumor cells of the dermis (IAP preparation), which can often be found on the calcaneal (Achilles) tendons or on the extensor tendons. Flat xanthomas (types III; IIA associated with primary biliary cirrhosis) are yellow neoplasms in the form of spots in the folds of the skin, especially in the folds of the palm. Xanthelasma (types IIA and III; also occurs without lipid abnormalities) are soft yellow plaques on the eyelids. Histologically, all tumor variants are characterized by clusters of histiocytes with abundant vacuolated (foamy) cytoplasm. In the cytoplasm of histiocytes, cholesterol (free and esterified), phospholipids and triglycerides are determined. The degree of cellularity of the tumor population with xanthomas is different, and, with the exception of xanthelasma, the central zones of neoplasms, consisting of histiocytes filled with lipids, can be surrounded by inflammatory infiltrate cells or a fibrosis zone. Vascular tumors of the dermis. Benign neoplasms developing from blood vessels (capillary and cavernous hemangiomas), malformations (capillary hemangioma), multifocal angioproliferative lesions (Kaposi’s sarcoma, bacterial angiomatosis) and malignant vascular tumors (angiosarcomas) are relatively common in the skin. The structure and various features of all vascular neoplasms, regardless of their localization, were discussed in Chapter 11.
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- Tumor-like processes and tumors of the dermis.
Among the cells of the numerous structural components of the dermis that are not related to the appendages of the skin, smooth muscle cells, pericytes, fibroblasts, elements of the nervous tissue and endothelium should be distinguished. All these cells can become sources of tumor growth. In most cases, skin tumors originating from the listed tissue elements do not differ from similar tumors of other locations. we
- TUMOR GROWTH. TUMOR PROGRESSION. TUMOR MORPHOGENESIS. INVASION AND METASTASIS OF MALIGNANT TUMORS. BIOMOLECULAR TUMORS MARKERS. ANTITUMOR IMMUNITY. PARANEOPLASTIC SYNDROMES. BASIC PRINCIPLES OF CLASSIFICATION OF TUMORS. MORPHOLOGICAL FEATURES OF TUMORS FROM EPITELIUM AND TUMORS FROM TISSUES - DERIVATED MESENCHIMES
TUMOR GROWTH. TUMOR PROGRESSION. TUMOR MORPHOGENESIS. INVASION AND METASTASIS OF MALIGNANT TUMORS. BIOMOLECULAR TUMORS MARKERS. ANTITUMOR IMMUNITY. PARANEOPLASTIC SYNDROMES. BASIC PRINCIPLES OF CLASSIFICATION OF TUMORS. MORPHOLOGICAL FEATURES OF TUMORS FROM EPITELIUM AND TUMORS FROM TISSUES - DERIVATIVES
- MESENCHYMAL TUMORS. TUMORS OF MELANINE-FORMING I FABRIC. TUMORS OF THE CENTRAL NERVOUS SYSTEM, BRAIN CELLS AND PERIPHERAL NERVES
MESENCHYMAL TUMORS. TUMORS OF MELANINE-FORMING I FABRIC. TUMORS OF THE CENTRAL NERVOUS SYSTEM, BRAIN CELLS AND PERIPHERAL
- Tumors: definition, nomenclature, classification. Tumor growth and molecular foundations of carcinogenesis. Tumors from the epithelium.
1. Basic theories of tumor growth 1. inflammatory 2. dysontogenetic 3. viral genetic 4. chemical carcinogens 5. physical carcinogens 2. Activation mechanisms of cell oncogenes 1. alteration 2. regeneration 3. proliferation 4. amplification 5. point mutation 3. Stages chemical carcinogenesis 1. promotion 2. initiation 3. alteration 4. proliferation 5. tumor progression 4.
- Mesenchymal tumors. Tumors of melanin-forming tissue
Mesenchymal tumors are tumors that develop from derivatives of mesenchyme - connective, vascular, muscle, fat, bone, cartilage, synovial membranes, fascia, tendons, aponeurosis. Among benign mesenchymal tumors, there are: 1) tumors of fibrous tissue — fibroma and dermatofibroma (histiocytoma); 2) adipose tissue tumors - lipoma, intramuscular
- Tumors of the mesenchymal tissue Tumors of adipose tissue
Lipoma. Benign tumor. The knot is the color of unchanged skin or a yellowish tinge, soft, often lobed, painless. Often, multiple tumors. Fibrolipoma. Fibrous tissue develops, and therefore the tumor has a dense texture. Liposarcoma Multiple nodes or diffuse infiltration in the subcutaneous tissue without a clear outline. The course is malignant. Metastases in
- Tumors of melanin-forming tissue
Tumors of melanin-forming tissue arise from melanocytes and melanoblasts, cells that synthesize melanin under the influence of tyrosinase, a pigment belonging to the group of melanin-forming. Nevus belongs to benign tumors, it is localized on the skin and is structured into: a) borderline; b) intradermal; c) complex; d) epithelioid [juvenile); e) blue. Malignant
- Mesenchymal tumors
1. The nature of the growth that prevails in malignant tumors: a) infiltrative b) expansive c) recurrent d) slow e) mixed The correct answer: a 2. The formation from which melanoma develops: a) nevus b) fibroma c) polyp g) desmoid e) sarcoma Correct answer: a 3. What is the histological type of fibrosarcoma: a) leiomyosarcoma b) fibrous cell c) fibrous g)
There are benign and malignant tumors. Benign tumors have the so-called expansive growth. It is characterized by the fact that normal tissues surrounding the tumor are squeezed and moved apart (or moved apart). Due to this, there are clear boundaries between the tumor and surrounding tissues and a capsule is formed, within which the tumor grows.
- Tumors from the epithelium
Tumors from the epithelium are the most common among tumors. The classification of epithelial tumors is based on histogenesis features (type of epithelium), degree of differentiation, and organ specificity. 1. Depending on histogenesis, tumors are distinguished from integumentary epithelium (stratified squamous and transitional) and glandular. 2. The flow, which is mainly determined by the degree
- Bone tumor
Causes A benign tumor in the bone or cartilage, bone cancer (in children), osteosarcoma (in the knee) - a malignant tumor of the bone, tuberculosis of the bones and joints, daughter tumors of cancer of the lung, thyroid, prostate, breast, and kidney. Symptoms Swelling and bone pain. First aid. Consult a specialist. Tumors are removed promptly. In especially severe cases (with
- Intraventricular tumors
Ventricular tumors are divided into primary, arising from the vascular plexuses and walls of the ventricles, and secondary are tumors of nearby structures that grow into the cavity of the ventricles. Primary ventricular tumors include ependymomas, choroid papillomas, meningiomas. The primary tumors of the third ventricle also include the so-called colloidal cysts and some types of craniopharyngiomas,
- Tumors in children
Tumors in children are much less common than in adults. Pediatric malignancies account for only 2% of all human cancers. However, among the causes of death in children, they occupy one of the leading places. In economically developed countries, child mortality from malignant neoplasms is second only to accidents and amounts to 10%. Tumors
- Mesenchymal tumors
Mesenchymal tumors originate from tissues of mesenchyme derivatives: connective (fibrous), adipose, muscle, vascular, bone, cartilage, as well as synovial and serous membranes. The source of mesenchymal tumors is a polypotent mesenchymal cell. The level of tumor transformation of the cell, the direction and block of differentiation determine the specific type of tumor: it can
- Pericardial Tumors
Primary pericardial tumors are less common than heart tumors. Clinical manifestations. Clinically, they are manifested by symptoms of hemorrhagic or serous-fibrous pericarditis, sometimes with suppuration. The diagnosis of pericarditis tumor is established by cytological examination of punctate contents of the pericardial cavity, the introduction of carbon dioxide into the pericardial cavity, histological examination
- BRAIN TUMORS
Patients with brain tumors make up about 4% among patients with organic lesions of the nervous system. Tumors of the brain in frequency occupy fifth place among tumors of other locations, giving way to tumors of the stomach, uterus, lungs and esophagus. There are brain tumors at any age, but there is some predominance in the puberty and at the age of 45-50
- Tumors of the brain and spinal cord
Brain tumors make up 10% of all neoplasms and 4.2% of all diseases of the nervous system. Spinal cord tumors are 6 times less common than brain tumors. Etiology. Among the causes of brain tumors can be called dysembryogenesis. It plays a role in the development of vascular tumors, malformations, ganglioneuroma. Genetic factor matters in the development of vascular
- HEART TUMORS
Definition Heart tumors are rare diseases with a polymorphic clinical picture. The first mention of a heart tumor dates back to 1559, when MR Columbus revealed a tumor in the left ventricle during a pathological study. Epidemiology Data on the prevalence of the most frequently detected primary heart tumors are given in table. 14.1. Rare development of heart tumors due to
- 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.
- Tumors of the kidneys.
In the kidney there are both benign and malignant tumors. Benign tumors are most often detected by chance at autopsy and rarely have clinical significance. Malignant tumors, by contrast, play a very important role. The most important are renal cell carcinoma, Wilms tumor, characteristic of childhood, as well as urothelial tumors of the calyx and pelvis.