To understand what an epithelial tumor is and what it happens, you need to understand what the tumor is and whether it is an oncology. It is very important. For example, epithelial tumors of the oral cavity can be benign or malignant.
Unfortunately, the number of people suffering from cancer is growing today, and mortality from this disease takes third place after deaths from diseases of the cardiovascular and respiratory system. Approximately six million new cases are recorded each year. Among men, the leaders were those citizens who live in France. And among women, the fairer women living in Brazil are more likely to get sick.
The increase in the incidence can be partly explained by the aging of the inhabitants of the planet, since people of mature and especially old age are more likely to suffer. According to statistics, every second cancer patient is a person over 60 years old.
What is cancer and what are tumors of epithelial origin? What is the difference between benign and malignant neoplasms and what are they?
What is cancer?
The term "cancer" is used in medicine as a generic name for cancer. It is characterized by uncontrolled proliferation of cells. Their aggressive growth affects both the organ itself, from where the “wrong” cells originate, and the nearby organs. Also, the malignant form of the tumor has a tendency to metastasis.
In men, the prostate and lungs are most often under attack, while in women, the mammary gland is a vulnerable organ, and the ovaries are slightly less likely. By the way, ovarian epithelial tumors in 80-90% of cases develop from epithelial tissue.
How healthy cells turn into cancer
The human body consists of billions of cells, all of them appear, divide and die at a certain moment, if they are healthy. All this is programmed; there is the beginning of the cell life cycle and the end. When they are normal, division occurs in appropriate quantities, new cells replace old ones. The process does not go beyond organs and tissues. The regulatory systems of the body are responsible for this.
But if the structure of the cells changes due to various factors, then they lose the ability to self-liquidate, cease to control their growth, growing into cancerous ones, and begin to multiply uncontrollably. That is, such cells are characterized by invasive growth.
The result of this is “modified cells” that are capable of long-term life activity. They eventually form a malignant tumor. Cancer can affect up to several organs at once. Unhealthy cells spread throughout the body through the lymphatic and circulatory system, spreading metastases.
Causes of cancer
The reasons for the development of oncology are varied, but specialists cannot unambiguously answer the question of what exactly caused the cancer in each individual case. Some believe that this is ecology, others blame genetically modified foods for this. In this case, all scientists identify factors that contribute to disruption of cell function, which ultimately can lead to a malignant form of the tumor.
A sufficient number of factors are known that affect the initiation of carcinogenesis. What can contribute to the disease?
- Chemical carcinogens. This category includes vinyl chloride, metals, plastic, asbestos. Their feature is that they are able to influence DNA cells, causing malignant degeneration.
- Carcinogens of a physical nature. These include various types of radiation. Ultraviolet, X-ray, neutron, proton radiation.
- Biological carcinogenesis factors are different types of viruses, such as the herpes-like Epstein-Barr virus, which causes Burkitt's lymphoma. Human papillomavirus can cause cervical cancer. Hepatitis B and C viruses contribute to liver cancer.
- Hormonal factors are human hormones, such as sex. They can affect the malignant degeneration of tissue.
- Genetic factors also influence the appearance of cancer. If previous relatives had cases of the disease, then the possibility of developing an ailment in future generations is higher.
Names of benign and malignant tumors
In the name of the tumor there is always the end of "ohm", and the first part is the name of the involved tissue. For example, a bone tumor is an osteoma, adipose tissue is a lipoma, vascular is an angioma, and glandular is an adenoma.
Sarcoma is a malignant form of mesenchyme. The diagnosis depends on the type of mesenchymal tissue, for example, osteosarcoma, myosarcoma, angiosarcoma, fibrosarcoma and so on.
A carcinoma or carcinoma is the name for a malignant epithelial tumor.
Classification of all neoplasms
The international classification of neoplasms proceeds from the pathogenetic principle, taking into account the morphological structure, the type of cells, tissues, organs, locations, as well as the structure in individual organs. For example, organ-specific or organ-specific.
All existing neoplasms are divided into seven groups. The group depends on the tumor belonging to a specific tissue and distinguishes them by histogenesis.
- epithelial tumors that do not have specific localization;
- tumors of exo or endocrine glands or specific epithelial tissues;
- soft tissue tumors;
- tumors of melanin-forming tissue;
- tumors of the brain and nervous system;
- hemoblastomas;
- teratomas, dysembryonic tumors.
Medicine divides two forms - benign and malignant.
Epithelial benign and malignant tumors
According to the clinical course, they share:
- benign forms of epithelium or epithelium;
- malignant, which is called cancer or carcinoma.
According to histology (type of epithelium) distinguish:
- neoplasm of the integumentary epithelium (stratified squamous and transitional);
- from glandular epithelium.
By organ specificity:
- organ-specific tumors,
- organ-specific (without specific localization).
Benign form
Benign epithelial tumors (epitheliomas) include:
- Papilloma (from the flat and transitional integument epithelium).
- Adenoma (from glandular epithelium). In a malignant form, it is a carcinoma.
Both species possess exclusively tissue atypism and have parenchyma and stroma. All known papillomas are a benign form of epithelial tumor, which, in turn, comes from the tissue of the integumentary epithelium.
Papillomas are formed on the surface of the skin from a flat or transitional epithelium. It may also not be on the surface, but, for example, in the mucous membrane of the pharynx, on the vocal cords, on the tissues of the bladder, ureters and pelvis of the kidneys or in other places.
Outwardly, they resemble papillae, and may resemble cauliflower. May be in a single manifestation, but may be multiple. Papilloma often has a leg that is attached to the skin. Tissue atypism occurs due to a violation of the main feature of any epithelium - complexity. With this violation, a failure occurs in a certain arrangement of cells and their polarity. With this benign tumor, expansive cell growth (basement membrane) is maintained. With expansive cell growth , the neoplasm grows by itself, increasing in size. It does not invade neighboring tissues, which would lead to their destruction, as with invasive growth.
The course of papillomas is different and depends on the type of affected tissue. Papillomas located on the surface of the skin (or warts) develop and grow slowly. Such formations, as a rule, do not cause much concern to their owners. But in the case of appearance in the internal parts of the body cause enough problems. For example, after removal of the papilloma from the vocal cords, they may appear again, since they are of a relapsing nature. Benign papillomas of the bladder may begin to ulcerate, which subsequently leads to bleeding and hematuria (blood appears in the urine).
Despite the fact that papillomatous neoplasms on the skin are a benign form of the tumor and do not cause much concern, malignancy of the tumor into a malignant one is still possible. This is facilitated by the type of HPV and predisposing external factors. There are more than 600 types of HPV strains, of which more than sixty have an increased oncogen.
Adenoma also refers to a tumor of epithelial origin and is formed from the glandular epithelium. This is a mature neoplasm. The mammary gland, thyroid, and others are a possible place for the location of the adenoma. It can also form in the mucous membranes of the stomach, in the intestines, bronchi and uterus.
The growth of adenoma cells, like papillomas, has an expansive growth pattern. It is delimited from the neighboring tissue and has the appearance of a knot of soft-elastic consistency, pinkish-white.
To date, the principle of development of this formation has not been fully studied, but usually it is possible to see the first disturbances in the balance of hormones - regulators of the function of the glandular epithelium.
In cases where a cyst is present in such a benign neoplasm, the term cysto- or cystoadenoma is used.
By morphological species, adenomas are divided into:
- fibroadenoma - an adenoma in which the stroma prevails over the parenchyma (often formed in the mammary gland);
- alveolar or acinar, which copies the end sections of the glands;
- tubular, able to maintain the ductal nature of epithelial structures;
- trabecular, which is characterized by a beam structure;
- adenomatous (glandular) polyp;
- cystic with a pronounced expansion of the lumen of the glands and the formation of cavities (this is precisely cystoadenoma);
- keratoacanthoma refers to an epithelial tumor of the skin.
A feature of adenomas is that they are able to degenerate into cancer, into adenocarcinoma.
Malignant form
This type of cancer can develop from the integumentary or glandular epithelium. Epithelial cancer can appear in any organ where epithelial tissue is present. This species is the most common among malignant forms of tumors. It is characterized by all the properties of malignancy.
All malignant neoplasms are preceded by precancerous conditions. At some point, the cells acquire cellular atypism, anaplasia begins, and they begin to multiply constantly. Initially, the process does not go beyond the epithelial layer and there is no invasive cell growth. This is the initial form of cancer, for which specialists use the term "in situ cancer."
If pre-invasive cancer is recognized during this period, then this will help get rid of further serious problems. As a rule, surgical treatment is performed, and in this case a favorable prognosis is outlined. The problem is that the patient rarely experiences any symptoms of the disease, and this "initial" cancer is difficult to detect, since it does not appear at the macroscopic level.
A malignant tumor from epithelial tissue by histogenesis can have the following character:
- transitional from the integumentary epithelium (squamous and transitional);
- basal cell;
- undifferentiated cancer (small cell, polymorphic cell, etc.);
- basal cell;
- squamous keratinizing cancer (malignant forms of the disease of the epithelial structure most often (up to 95%) are represented by squamous keratinizing cancer;
- squamous non-keratinized cancer.
A separate category is mixed forms of cancer. They consist of two types of epithelium - flat and cylindrical. This kind is called "dimorphic cancer."
Cancer originating from the glandular epithelium:
- Colloidal and its variety - cricoid cancer.
- Adenocarcinoma. By the way, the name of this tumor was given by Hippocrates. He compared her appearance with a crab.
- Solid cancer.
Experts also distinguish by features the following tumors from epithelial tissue:
- medullary, or cerebral, cancer;
- simple cancer, or vulgar;
- Skirr, or fibrotic cancer.
Symptoms of cancer
Symptoms of the disease depend on where exactly the tumor developed, in which organ, on its growth rate, as well as the presence of metastases.
Common symptoms:
- Change in the condition of the skin in a certain area in the form of a growing swelling, which is surrounded by a rim of hyperemia. Swelling can begin to ulcerate, ulcers appear that are difficult to treat.
- Change in the timbre of the voice, it is difficult for a person to swallow, coughing in fits, pain in the chest or abdomen.
- The patient can lose weight significantly, he is characterized by poor appetite, weakness, persistent fever, anemia, tightness in the mammary gland and bloody discharge from the nipple or bladder, difficulty urinating.
But other symptoms may be present.
Cancer diagnosis
A timely visit to a specialist is required for a thorough examination and a detailed collection of tests. Diagnostic methods for detecting a disease include:
- physical method for studying the patient;
- computed tomography, MRI (considered a very effective method), radiography;
- blood test (general and biochemical), identification of tumor markers in the blood;
- puncture, biopsy with morphological examination;
- bronchoscopy, esophagogastroduodenoscopy.
All these measures will help to detect the disease at an early stage and completely cure the patient.