Nomenclature, classification, structure and development of tumors

Tumors are composed of parenchyma and stroma (Fig. 3)originating from surrounding the tumor tissue. At occurrence of tumors see significant changes vessels and nerves. The vessels dilate, form a kind plexus type of vascular tangle become sharply atypical, considerably differing from vessels normal tissues. The vessels are Acting more subtle, imperfect built walls, often stretched, filled with blood, are often gaps, the wall of which is made up of one endothelium; they contained the blood of seats directly washed by the tumor tissue. Due to insufficient blood supply of tissues About. it often arise necrosis.

Fig. 3. Squamous non-squamous skin cancer.

Nerves in the tumor are also very different from normal. Nerve cells form a focal expansion is woven into the focal proliferation other tissues. In those cases, when Acting poor stroma, nerve fibers, it is small and difficult to detect; this was the reason to believe that Acting deprived of nerves and that this explains their kind of "Autonomous" growth. Later, it was found that tumors can be detected nerve fibers, but they greatly changed: they can watch all the known phenomenon of degeneration, and in some areas and nerve regeneration, change of their branches, the violation of the structure of shells of nerves, etc., In the areas of necrosis vessels and nerves decompose.
The item's Acting reflected their tissue of origin, particle "OMA", representing the end of the word "blastoma", joins the word for this or that fabric. For example, a tumor of the cartilage - chondroplasty - called chondroma of muscle tissue, uterine (of smooth muscles - leiomyomas, striated - rhabdomyoma), etc. Among the Acting nervous tissue distinguish ganglioneuroma, neuroma, gliomas, and among the last - astrocytomas, astroblastoma, specialistami etc.
Some tumors retain special, historically entrenched behind them names. So, malignant Grilles of connective tissue called sarcoma (see), because in the context of her cloth resembles fish meat (gr. sarkoma fleshy growth, growth; from sarx, sarkos - meat). Malignant epitelioma is called cancer, carcinoma (see). The term "cancer", "cancer" is a translation of the Greek words "karkinos", "karkinoma". In many countries, for example France this term in Latinized version - "cancer" - refers to all malignant Acting independently of their tissue of origin and structure. In the USSR and several other countries, cancer is called only malignant epithelial O.
A special place is occupied by the Acting system and hyperplasia of blood-forming tissue. Currently leukaemia (see) and even chlamydia (see) refer to tumor diseases.
Pathological classification of tumors is based on the principle of belonging them to this or that fabric. Accordingly, four kinds of tissues distinguish epithelium, connective tissue, muscle and nerve Acting Within each tissue group of pathological classification is based on the morphological structure and histogenesis About. So, epithelial O. divided into originating from glandular epithelium and flat; in that case, when Acting in visible patterns glands (Fig. 4), it is called an adenoma (see) or adenocarcinoma (Fig. 5), and so on, Grilles of squamous epithelium in turn are divided on the nature of cancer and for whatever its ability to keratinization on orogovevshie (Fig. 6) and non-squamous (Fig. 3) cancer O. Connective tissue O. depending on the type of tissue (fiber, fat, cartilage, bone) are divided into fibroids, lipoma, handsome, osteomas, etc. Among sarcomas there are spindle-polymorphic - and round-cell.
Many malignant tumors of soft tissues, which first took to the sarcomas, currently defined as tumor originating from muscle tissues and membranes of the peripheral nerves.

Fig. 4. Three small adenomas of the kidneys. The multiplicity and multicentricity arise. The lack of infiltrative growth.
Fig. 5. Breast adenocarcinoma.
Fig. 6. Squamous cell orogovevshi skin cancer. Clearly visible "pearls".
Fig. 7. Serosny breast cancer.

In cases where the parenchyma is not the connective tissue, such as in the epithelial Acting, talking about organoidny their structure, i.e. which resembles the structure of authority, in which the parenchyma consists of epithelial tissue and sharply differs from the stroma (e.g. liver). In connective tissue O. often impossible to distinguish stroma from parenchyma, as both belong to the same species tissue. Unlike organoidny, such O. called gestionali, i.e. reminiscent in structure of the fabric.
Part of parenchymal tumors may contain multiple tissues - mixed O. these include various types of CERATOM and ambrym. Sometimes the Acting is "mixed" only by its morphological picture, but not tissue origin - histogenesis. For example, the so-called mixed tumors (see) parotid gland and other salivary glands are purely epithelial tumors.
From mixed tumors should be distinguished di-, tri -, or polymorphic cancer Acting in Almost every cancer Acting with careful research you can find lots of different structures. This is due to multicentricity appearance and different structure of the rudiments of cancer and the variability of the cancerous tissue.
According to the degree of differentiation of most sites About. can be divided into undifferentiated, little differentiated and highly differentiated forms, such as various kinds of poorly differentiated sarcomas and fibrosarcoma, undifferentiated cancer and adenocarcinoma, orogovevshi squamous cell carcinoma.
The ratio between the stroma and the parenchyma cancer tumors are divided into rich stroma, dense cancer - skirr (Fig. 7), poor stroma, soft, or mozgoviy, cancer and "simple" cancer with an average number of stroma. This division is not opposed to the classification on a fabric basis, but complements it.
Along with the classification of Acting on tissue principle some O. called by the authority or a certain part of, for example hepatoma - Grilles of liver cells, insuloma - of fabrics of the pancreatic islets, nevalennyi Acting - out of special elements of the skin. These names are in many cases better determine not only the structure and origin, but also pathophysiological features and value of certain cancers for the body.
Clinical and morphological point of view distinguish between benign and malignant tumors; morphological criterion is the nature of their growth. Benign O. possess the so-called expansive growth, only pushing and pushing (and sometimes compressive) the surrounding tissue, but without germination and their destruction (Fig. 8). Malignant O. differ infiltrative growth (Fig. 9), grow into the surrounding tissue and destroy them. With infiltrative and destroyuser growth is connected and the possibility of metastasis O. characteristic of malignant tumors. Benign About. not metastasize. Only in very rare cases, see metastases (see) morphologically benign tumor (adenoma of the thyroid gland, and sometimes gondrom). Some benign O., such as the brain, can represent a great danger in connection with its localization.

Fig. 8. Basal cell carcinoma of the skin.
Fig. 9. Infiltrative growth in the deep parts of HPV bladder. The beginning of cancer.
Fig. 10. Retikulosarkoma skin infiltration of the dermis.
Fig. 11. Polymorphonuclear bladder cancer strongly anaplasia cells.

Of atypia is one of the cardinal signs of tumor growth. The appearance of Acting as separated from the surrounding tissues education is a sign of atypia.
This is followed by cellular atypia tissues and cells (figure 10 and 11), as the tumor in its structure, location and relations between its elements differs sharply from the source of normal tissue. Cells Acting are less differentiation than normal, less or greater magnitude (oligochetes and megalocytes), polymorphism, etc., In malignant O. cellular atypia especially pronounced (differences in shape, size, crashevenmore, relations nucleus to the cytoplasm, the frequency of Mitasov, uneven mitoses, nuclei are atypical, chromosomes, an increase of nucleoli and other). Therefore, we can speak not only about the atypia of tumor cells, but also about the atypia all the parts of cells, down to the smallest of the particles. Changing crashevenmore tumor cells, as well as various histochemical methods of researches allow to judge about changes of biochemical composition and energy of the tumor cells, changing them in the normal ratio and the number of nucleic acids and so on Electron microscopic studies, although still far from finished, showed a cellular atypia of the subtlest structures of the tumor cells, simplification and the irregular structure of total AIDS special syntheses (elastoplast), changes of mitochondria, a kind of hydropic degeneration of cytoplasm, changes of protein filaments, increasing the number of cytoplasmic ribosomes, not associated with membranes, and other
The phenomenon of atypia tumor tissue is increasing gradually, with the development of tumors, and in already formed tumors they are not the same. The degree of malignancy different Acting different. Numerous attempts were made to establish the degree of malignancy, and even to give a forecast for the treatment of certain tumors based on morphological analysis of the degree of malignancy. Clinical use of the results of such analysis is usually hampered by the fact that the clinical picture of the disease degree of malignancy the Acting is just one of the components along with its localization, complications, and so on (see below).
Lately, in General Oncology included the idea of "progression" Oh, This term define, in particular, the possibility of increasing the malignancy Acting, and the main thing - increase their independence from correlated systems of the body, increase their autonomy. The basis of representation about progression Acting on the results of those experiments on animals, in which tumors, experimentally caused that or other hormonal imbalance, for its future growth, for example in terms of inoculation, needed first in hormonal influences, and later grew up without them. In this regard, some of these tumors can be considered at a certain stage of their development of hormone-dependent, but on further stages of hormonal independent.

Great importance is the principle of independent progression of individual characteristics O. for example, the tumor may metastasize, but remain dependent on hormones, the degree of morphological of malignancy may not match the ability to invasive growth and so on, the Idea of progression O. may be important for understanding not only development, but also the treatment of many tumors. In direct connection with the progression of O. there is a question and on their recurrence and metastasis. Both these phenomena become possible only when purchasing a cell O. certain degree of independence, autonomy, and, of course, at the change of reactivity, i.e. in the fall of organism resistance.
Metastasis is Acting normally in direct connection with infiltrative destroyuser their growth. With this growth destroyed the walls of blood vessels in the surrounding malignant tumor tissue, these vessels grow into the tumor cells, which then fond bloodstream and spread to the laws embolism (see) to other tissues and organs.
In the process of metastasis should distinguish four stages: 1) invasion - penetration of malignant cells in the blood vessels; 2) transport - transfer of malignant cells in the blood or lymph; 3) implantation - saving and engrafted cells migrated to the new location; 4) their growth and development of new, secondary, tumor node (Fig. 12). Each of these steps is essential for later, and therefore the development of metastases is a consequence of the implementation of all stages of this process. However, not each of them always goes to the next, and the process of metastasis can end at any stage. It is known that in blood of patients can be found in cancer cells, and in some organs, such as lung, spleen,cancer emboli, which do not develop metastases. These observations indicate the importance of immune status of the organism in the development of tumor.

Fig. 12. Metastasis (left) experimental lung cancer rats in the lymph nodes in the mediastinum.

However, already developed, Acting in turn affects the entire body.
The great value has the tumour localization, because it can determine the immediate danger of a tumor on the body. So, cancer of the esophagus leads to starvation; cancer of any part of the digestive tract violates food; O. brain can compress vital centers, etc., In malignant Acting as its development often have necrobiosis and tissue necrosis, ulceration and bleeding, leading to severe anemia, sometimes fatal.
Malignant Acting quickly disintegrate. This parenteral absorbed a large number of products of tissue decay. Specific cancer toxins that could explain the General poor condition with cancer, practically was not found. However, the impact of disruption of all types of currency, combined with the increasing absorption of the decay products tumor tissue allows to explain the intoxication of the organism in malignant O. Itself Acting continuously growing, consumes a number of products, necessary for the human body. Some authors call the tumor "trap of nitrogen".
Breakdown and ulceration of malignant O. represent a fertile ground for the development of secondary infection. Almost all About., soamsawali with outer environment, infected, inflamed and capable of suppuration. The number of infectious and purulent complications O. decreased mainly as a result of application of antibiotics, however, the role of secondary infection in the intoxication of the organism of the patient with cancer remains significant.
Over time the effect of Acting on the body grows and leads in some cases to severe condition of patients, which is a common name cancer cachexia (see).