Malignant tumor and benign: differences, types
A malignant tumor is a pathological process, accompanied by uncontrolled, uncontrolled proliferation of cells that have acquired new properties and capable of unlimited division. Cancer incidence and mortality has long gone into second place, behind only heart disease and blood vessels, but the fear that causes cancer in the vast majority of people, disproportionately higher fear of diseases of all other organs.
As you know, the tumors are benign or malignant. Features of the structure and function of cells determine the tumor behavior and prognosis for the patient. At the stage of diagnosis, the most important is the establishment of the malignant potential of the cells, which will predetermine further actions of the doctor.
Cancer include a malignant tumor. To this category and it is a benign process, which all the same do oncologists.
Among malignant tumors the most common cancers (epithelial neoplasia).
The largest number of cases in the world are lung, stomach, breast, body, and cervix in women.
A growing number of newly identified tumours of the colon, skin, prostate.
Among benign tumors the most common skin papillomas, hemangioma, leiomyoma of the uterus.
Properties of malignant tumors
In order to understand the nature of tumor growth, it is necessary to consider the basic properties of cells that make up tumors that allow tumors to grow irrespective of the whole organism.
Malignant tumors presented cancer, sarcomas, tumors of the nervous and melaminovaya tissue, teratoma.
Cancer (carcinoma) is a tumor of epithelial tissue composed of highly specialized and ever-changing cells. The epithelium forms the epithelial layer of the skin, the lining and the parenchyma of many internal organs. Epithelial cells are constantly updated instead of outdated age or damaged, the formation of new, young cells. The process of reproduction and differentiation of the epithelium is controlled by many factors, some of which are restrictive, not allowing uncontrolled and excessive to share. Violations at the stage of cell division usually leads to the appearance of tumors.
Sarcoma – connective tissue malignant tumours originating from bones, muscles, fat, tendons, vessel walls, etc. Sarcomas occur slightly less often of cancer, but prone to more aggressive course and early dissemination through the blood vessels.
Tumors of the nerve tissue can be attributed neither to the actual cancer nor sarcoma, so they are placed in a separate group, as melaminovaya neoplasms (nevi, melanoma).
A special kind of present tumors teratoma that appears during prenatal development in violation of the displacement of embryonic tissues. Teratomas are benign and malignant.
Features of malignant tumors that allows them to exist, regardless of the body, subjecting it to their needs and bringing waste products are reduced to:
- Cellular and tissue atypia;
- Uncontrolled multiplication of cells, their unlimited growth;
- The possibility of metastasis.
The emergence of the capacity for Autonomous, independent existence — the first change that occurs in cells and tissues towards tumor formation. This property is predetermined genetically by mutation of the relevant genes responsible for cell cycle. A healthy cell has a limit in the number of its divisions and sooner or later cease to proliferate, unlike the tumor, which is not subject to any signals of the body divides continuously and indefinitely. If the tumor cell to be placed in favorable conditions, she will share years and decades, giving the offspring of such defective cells. In fact, the tumor cell is immortal and can exist in a changing environment, adapting to it.
The second important characteristic of the tumor believe atypia, which can be detected already at the stage of pre-cancer. In established tumors, the atypical may be expressed to the extent that the nature and origin of the cells is impossible. Atypia is new and different from the norm, properties of cells, affecting their structure, functioning, characteristics of the exchange.
In benign tumors of the tissue atypia is present, namely, the violation of the ratio between the volume cells and the surrounding stroma, the tumor cells according to the structure as close as possible to normal. Malignant neoplasms, in addition to tissue and cellular atypia, when the cells undergoing neoplastic transformation are significantly different from normal, gain or lose the capacity for certain functions, synthesis of enzymes, hormones, etc.
Properties of malignant tumors are constantly changing, its cells acquire new features, but often in the direction of greater malignancy. Modify the properties of the tumor tissue reflects its adaptation to the existence in a variety of conditions, whether the surface of the skin or mucosa of the stomach.
The most important ability of distinguishing malignancy from benign is metastasis. Normal cells of healthy tissues and those close to them elements of benign tumors are closely linked by intercellular contacts, therefore, a spontaneous separation of the cells from the tissue and their migration is not possible (of course, except where this property is needed – bone marrow, for example). Malignant cells lose surface proteins responsible for intercellular communication, detached from the primary tumor, invade vessels and spread to other organs, spread over the surface of serous integument. This phenomenon is called metastasis.
If metastasis (spread) of the tumor occurs through the blood vessels, the secondary tumor accumulation can be detected in the internal organs – liver, lungs, bone marrow etc. In the case of metastasis in lymph vessels, the defeat would affect the lymph nodes that collect lymph from the place of primary localization of neoplasia. In advanced cases of the disease, the metastases can be detected at a considerable distance from the tumor. At this stage the prognosis is poor and patients can be offered only palliative care to ease symptoms.
An important feature of malignant tumor, distinguishing it from a benign process, is the ability to grow (invasion) in the adjacent tissue, damaging and destroying them. If a benign tumor like tissue pushes, squeezes them, may cause atrophy, but does not destroy, malignant tumor, highlighting a variety of biologically active substances, toxic products of metabolism, enzymes, embedded in the surrounding structures, causing their damage and death. With the capacity for invasive growth it is also associated metastasis, and this behavior often does not allow to completely remove the neoplasm, without violating the integrity of the authority.
Cancer is not only the presence of more or less localized cancer. Always at the malignant nature of the lesion takes place and the overall effect of neoplasia on the body, which is compounded from stage to stage. Common symptoms include the most famous and is characterized by loss of weight, extreme weakness and fatigue, fever, difficult to explain at the initial stages of the disease. As the progression of the disease develops cancer cachexia with a sharp depletion and impaired function of vital organs.
Properties of benign tumors
A benign tumor is also in the field of view of cancer, but the risk and the prognosis for it is incomparably better than in malignant, and in most cases prompt treatment allows you to completely and permanently get rid of it.
Benign tumor consists of cells to the same extent developed that can accurately determine its source. Uncontrolled and excessive multiplication of the cellular elements benign tumors combined with their high differentiation and an almost complete conformity to the structures of healthy tissue, so in this case they say is only on the tissue atypia, but not on cellular.
About the neoplastic nature of benign tumors say:
- Inadequate, excessive multiplication of cells;
- The presence of tissue atypia;
- The possibility of recurrence.
A benign tumor does not metastasize, because its cells are interconnected, not growing into nearby tissue and, therefore, does not destroy them. As a rule, there is no overall impact on the body, with the exception only of education, which produce hormones or other biologically active substances. The local effect is to push the healthy tissue, compression of them and of atrophy, the severity of which depends on the location and size of growths. For benign processes are characterized by slow growth and low probability of recurrence.
Of course, benign tumors do not inspire such fear, like cancer, but they can be dangerous. So, almost always there is the risk of malignancy (malignancy), which may occur anytime, whether a year or decades since the onset of the disease. The most dangerous papilloma of the urinary tract, certain types of nevi, adenomas, and adenomatous polyps of the gastrointestinal tract. At the same time, some tumors, for example, lipoma, consisting of fat tissue is not malignant and is able to deliver only a cosmetic defect, or be influenced in view of their size or the nature of the location.
Kinds of tumors
For systematization of information on known tumors, unification of approaches to diagnosis and therapy developed for the classification of tumors based on their morphological features and behavior in the body.
The main criterion that allows to divide the tumors into groups is the structure and source. Both benign and malignant neoplasias are epithelial in origin, may consist of a connective-tissue structures, muscles, bone, etc.
Malignant tumors of epithelial origin combined term «cancer», which happens to be glandular (adenocarcinoma) and originating from the MBE (squamous cell carcinoma). Each type has several levels of cell differentiation (highly, moderately, nizkotemperaturnye tumor) which determines the aggressiveness and course of the disease.
Benign epithelial neoplasia include papillomas, originating from a flat or transitional epithelium, adenoma, consisting of glandular tissue.
Adenoma, adenocarcinoma, papilloma does not have the organ built differences and stereotyped in different localizations. There are forms of tumors, characteristic of specific organs or tissues, such as fibroadenoma of the breast or renal cell cancer.
Much more variety, in contrast to epithelial tumors, and different tumors originating from the so-called mesenchyme. In this group include:
- Connective tissue formation (fibroma, fibrosarcoma);
- Fat neoplasm (lipoma, liposarcoma, tumors of brown fat);
- Tumors of muscle (rhabdo — and leiomyoma, miosarkomy);
- Bone tumors (osteoma, osteosarcoma);
- Vascular neoplasm (hemangiomas, lymphangioma, vascular sarcomas).
The appearance of a tumor is very different: in the form of a constrained node, cauliflower, mushroom, in the form of unstructured growths, ulcers, etc. the Surface is smooth, rough, nodular, and papillary. In malignant diseases often found secondary changes reflecting disturbed metabolism of cells and their ingrowth in surrounding structures: hemorrhage, necrosis, suppuration, mucus, cysts.
Any microscopically the tumor consists of a cellular component (parenchyma) and stroma that performs supportive and nutritive role. The higher the degree of differentiation of the tumor, the more orderly will be and its structure. In nizkoeffektivnyj (highly malignant) tumors of the stroma may be a minimal amount, but the bulk of education will be malignant cells.
Tumors of different localization is ubiquitous in all geographic areas are not spared neither children nor the elderly. Appearing in the body, the tumor is skillfully removed from the immune response and protective systems aimed at the removal of all alien. The ability to adapt to different conditions, changing the structure of cells and their antigenic properties, allows the tumor to sustain itself, «taking away» from the body all the necessary and returning the products of their metabolism. Having arisen once, the cancer has been completely subjugates the work of many systems and organs, disabling them their livelihoods.
Scientists around the world are constantly fighting with the problem of tumors, looking for new ways to diagnose and treat disease, identify risk factors, establish genetic mechanisms of cancer. It should be noted that progress, albeit slowly, but happening.
Today, many tumors, even malignant, are amenable to successful therapy. The development of surgical techniques, a wide range of modern anticancer drugs, new techniques of irradiation allows many patients to get rid of the tumor, but a priority for research is the search for means to combat metastasis.
The ability to spread throughout the body makes a malignant tumor is almost invulnerable, and all the available treatment is ineffective in the presence of secondary tumours of conglomerates is found. I hope that this mystery tumor will be solved in the near future, and the efforts of scientists will lead to the emergence of truly effective therapy.