Carcinoma (cancer): squamous, papillary
Carcinoma known to mankind since time immemorial. The first mention of such tumors can be found in ancient Egyptian papyrus, and Hippocrates made their name – carcinoma, because outwardly they resembled crabs. Later, Celsus translated the term in Latin, so there was a «cancer». Even in ancient times, the carcinoma is considered an incurable disease, but even then, it was proposed to remove the tumorous tissues in the early stages, but advanced cases are not treated at all.
As time went on, the performances were varied, however, and today, the cancer often remains an incurable disease. The more scientists learn about it, the more there is new questions. Even modern methods of diagnosis are not always able to detect cancer at an early stage, and treatment often does not bring the expected fruit.
Malignant tumors are considered to be leaders in the number of deaths worldwide, the first place they lost only to diseases of the cardiovascular system, and among all neoplasia carcinoma – the most common variety.
The term «cancer» in medicine denotes a malignant tumor from the epithelium. This concept is identical to carcinoma.
These tumors have a peculiar structure, are subject to some General mechanisms of development and behavior. The source may be skin, mucous membranes, the parenchyma of internal organs, consisting of highly specialized functional relationship of cells (liver, pancreas, lungs, etc.). Often people unrelated to medicine, called cancer and other tumors, for example, from bone, muscle or nervous tissue, however, this is incorrect. In this article we will try to understand what is carcinoma (cancer), where it grows and how to fight it.
Carcinoma is much more common than all other types of malignant tumors, and there is a good reason. The fact that the epithelium covering the inner surface of many organs, or forming the top layer of skin, constantly updated, and it is associated with continuous cell division. The more intense divide and multiply cells, the more likely that at some point may crash and this will cause the appearance of spontaneous genetic mutations. The mutated cell gives rise to a clone of new, changed, with an uncharacteristic structure or properties, which, moreover, is capable to divide unlimited number of times. So, in a short time there will be education of a different structure from the epithelium from which it occurred, and the ability to rise rapidly, to grow into the surrounding space, spread by the blood or lymph throughout the body and will determine its malignant nature.
Another possible reason for the prevalence of tumors of the epithelium can be considered a high probability of contact with carcinogens. So, the skin experiencing all sorts of environmental influences (sun, household chemicals, wind), the epithelium of the gastrointestinal tract is constantly in contact with the carcinogens contained in food, in the lungs gets contaminated air and tobacco smoke, the liver is forced to metabolize a variety of toxic substances, medicines, etc., while the cardiac muscle or nervous tissue of the brain is restricted from such hazards barriers.
The epithelium of the female genital organs and prostate are subject to the action of hormones that cause there is a complex transformation, so if any hormonal disruptions, especially likely in aged patients, it may cause a violation of the maturation of epithelial cells.
Cancer does not appear suddenly on the intact epithelium, it is always preceded by a precancerous change. Because not everyone rushes to the doctor if there are any complaints, and certain types of pre-cancer and is asymptomatic, and cases are diagnosed when the tumor directly, bypassing its predecessors, are not uncommon.
To precancerous changes include dysplasia, leukoplakia, atrophic, or hyperplastic processes, but the most important is dysplasia, severe degree which, in fact, is «cancer in place», that is a non-invasive form of cancer.
Types of tumors from epithelium
Carcinoma is extremely diverse, both in appearance and microscopic characteristics, but on the basis of shared characteristics, they were classified into groups.
Externally, the tumor may resemble a knot or rise in the form of infiltration, infiltrating into the surrounding tissue, clear boundaries for cancer is not peculiar, but the process is often accompanied by a pronounced inflammation and a tendency to ulceration, especially on the skin and mucous membranes.
Depending on the type of epithelium, which gave rise to carcinoma, usually distinguished:
Adenocarcinoma can have the different structure, Recalling a certain structure of healthy tissue, so separate them:
- Papillary carcinoma when tumor complexes form a branching papillary proliferation (eg. in the thyroid gland).
- Tubular adenocarcinoma – the tumor cells are formed in the likeness of tubes and ducts.
- Acinar – like acini or rounded clusters of cancer cells.
Depending on the degree of maturity of tumor cells, glandular carcinoma may be highly, moderately- and low-grade. If the structure of the tumor close to a healthy epithelium, we speak of a high degree of differentiation, while poorly differentiated tumors sometimes lose resemblance to the original tissue from which it was formed. Always in carcinoma there are signs of malignancy as cell atypia, increased, large and dark-colored core, the abundance of defective (abnormal) mitoses (dividing nuclei), polymorphism (one cell is different).
Squamous cell carcinoma is wired a little differently. It is possible to find the field of stratified squamous epithelium, but consisting of a modified abnormal cells. In more favorable cases, such cancerous epithelium retains the ability to the formation of Horny substance, which accumulates in the form of pearls, then talk about a differentiated variety of squamous cell carcinoma – keratinizing. If this ability is deprived of the epithelium, the cancer will be called neorogovevayuschy and have a low degree of differentiation.
Describes the varieties are established using histological examination of fragments of tumor tissue after a biopsy or remove it during surgery, but can only indirectly indicate the degree of maturity and the structure of carcinoma.
The lower the differentiation, i.e. the development of cancer cells, especially a malignant tumor, so it is important to make it a microscopic study and describe all the features.
The greatest difficulty may arise in the diagnosis of low-grade cancer when the cells in the extent varied or, conversely, are virtually the same that do not fit into any of the above variants of cancer. However, some forms still manages to highlight: slimy, solid, small cell, fibrous (scirr), etc. If the structure of the tumor does not match any of the known types, it is called unclassified carcinoma.
Features of the main types of nizkoeffektivnyj carcinoma:
Of the glands of internal secretion may develop neoplasia, the cells of which retain similarities with the original tissue organ, such as hepatocellular carcinoma that develops from hepatocytes in the liver and growing a large site or multiple small nodules in the parenchyma of the organ.
In rare cases it is possible to detect the so-called carcinoma of unclear origin. In fact, a cancer metastasis, the initial location to install and failed, even with the involvement of all available research methods.
Carcinoma from an unknown source often found in the lungs, liver, lymph nodes. In such a situation, crucial may have a biopsy and immunohistochemical study of fragments of the tumor, allowing to determine in it the presence of proteins common to a specific type of cancer. Of particular difficulty is the diagnosis nizkoeffektivnyj or undifferentiated forms of carcinoma, when their structure has similarities to the alleged source of the metastasis.
Speaking of malignant tumors, it is important to define the concept of invasiveness. The transition of the precancerous process to carcinoma is accompanied by changes characteristic of cancer, in the whole thickness of the epithelial layer, but outside the tumor may not go out and invade the basal membrane – «cancer in place», carcinoma «in situ». So from time to time behaves ductal carcinoma of the breast or cancer «in situ» of the cervix.
Due to the aggressive behavior, the ability of cells to indefinitely divide to produce a variety of enzymes and biologically active substances, carcinoma, overcoming stage non-invasive cancer that grows through the basal membrane, which was located on the epithelium to penetrate into the underlying tissues, destroying the walls of blood and lymphatic vessels. This tumor be called invasive.
One of the most common malignant epithelial tumor is a carcinoma of the stomach, occurring predominantly among the male population of Japan, Russia, Belarus, Baltic countries. Build it in most cases corresponds to the adenocarcinoma – glandular tumor, which can be papillary, tubular, trabecular, etc. Among undifferentiated forms can be detected mucous (prestavitelyami cancer), and this kind of as squamous cell carcinoma in the stomach is extremely rare.
Carcinoma of the cervix is also not a rare pathology. It is diagnosed not only in elderly but also in young patients of reproductive age on a background of various pre-cancerous processes (pseudo, leukoplakia), viral infection or scar deformities. Since most of the cervix covered with stratified squamous epithelium, it is most likely the development of squamous cell carcinoma, and cervical canal, which leads into the uterus and is lined with glandular epithelium, which is more typical of adenocarcinoma.
Skin tumors are extremely varied, but the most common variant is considered to be basal cell carcinoma (basal cell carcinoma). This tumor affects elderly people, and a favorite place of localization is the face and neck. Basal cell carcinoma has a feature: if there are signs of malignancy in the cells and ability to grow into the underlying tissues, it never metastasizes but grows slowly and shows a tendency to recurrence or the formation of multiple nodules. This form of cancer can be considered a favorable prognosis, but only if timely treatment to the doctor.
The clear cell variant of carcinoma is the most common malignant tumor of the kidney. Its name suggests that it consists of light cells of various shapes, within which are found the inclusion of fat. This cancer grows rapidly, metastasizes early and is prone to necrosis and hemorrhage.
Carcinoma of the breast presents a variety of forms, which include lobular and ductal variety, which is «cancer in place», that is, non-invasive options. Such tumors grow within the lobules or the milky duct, a long time can not be felt and does not show any symptoms.
The time of development of infiltrating breast carcinoma characterizes the progression of the disease and its transition into the next, more severe stage. Pain and other symptoms for invasive cancer is not peculiar, and women themselves often find the tumor (either at the scheduled mammogram).
A special group of malignant tumors are of neuroendocrine carcinoma. The cells from which they are formed, dispersed throughout the body and their function is in the formation of hormones and biologically active substances. In tumors of neuroendocrine cells, there is a characteristic symptoms, depending on the type of tumor formed by the hormone. So, possible nausea, diarrhea, rises blood pressure, hypoglycemia, fatigue, development of stomach ulcers, etc. According to its clinical features neuroendocrine carcinomas are extremely diverse.
The world health organization was requested to provide:
- Vysokomehanizirovannoe neuroendocrine carcinoma benign course;
- Vysokomehanizirovannoe carcinoma with a low degree of malignancy;
- Poorly differentiated tumors with high tumor grade (large-cell carcinoma and small cell neuroendocrine carcinoma).
Carcinoid tumors (neuroendocrine) are more common in the gastrointestinal tract (Appendix, stomach, pancreas, small intestine), lungs, adrenal glands.
Urothelial carcinoma is transitional cell cancer of the bladder, constituting more than 90% of malignant neoplasms of this localization. The source of such tumour becomes the transitional epithelium of the mucous membrane, having similarities with a single layer of squamous and glandular at the same time. Urothelial cancer is accompanied by bleeding, dysuric disorders and are often diagnosed in elderly men.
More specific types of carcinomas of different organs described in the materials dedicated to specific types of cancer, so here we only briefly touched upon the main features.
Metastasis of carcinoma occurs mainly by lymphogenous, which is associated with good development of the lymphatic networks in the mucous membranes and parenchymal bodies. First, metastases are found in nearby lymph nodes (regional) in relation to the growth of cancer. With the progression of the tumor, growing in her blood vessels appear and hematogenous screenings in lungs, kidneys, bones, brain, etc. the Presence of hematogenous metastases in malignant epithelial tumors (cancer) always indicates a far advanced stage of the disease.
How to identify and how to treat?
Methods of diagnosis of carcinomas are quite diverse and depend on the localization of the tumor. So, in order to indicate certain types of cancer a simple examination (cancer of the mouth, lips, skin) and for other tumors to help oncologists come instrumental and laboratory methods of research.
After inspection and conversations with the patient, the doctor always assigns the General and biochemical analysis of blood, urine. In the case of the localization of carcinoma in the cavernous bodies of resort to endoscopy – fibrogastroduodenoscopy, cystoscopy, hysteroscopy. A large amount of information can give radiological techniques – radiography, excretory urography.
For the study of lymph nodes, spread of the tumor into the surrounding tissue are essential to CT, MRI and ultrasonic diagnostics.
In order to exclude metastases are usually held radiography of the lungs, bones, ultrasound of the abdominal organs.
The most informative and accurate method of diagnosis are considered morphological examination (cytological and histological) that allows you to set the type of the neoplasm and its degree of differentiation.
Modern medicine offers and cytogenetic analysis for the detection of genes indicating a high risk of developing a particular type of cancer and determination of tumor markers in the blood (prostate specific antigen, SCCA in cases of suspected squamous cell carcinoma, etc.).
Early diagnosis of cancer based on the determination of tumor specific proteins (markers) in patient’s blood. So, in the absence of visible foci of neoplasm growth and increase of certain indicators can suggest the presence of disease. Furthermore, squamous cancers of the larynx, cervix, nasopharynx detection of a specific antigen (SCC) may indicate the probability of recurrence or progression of the tumor.
Treatment of carcinoma is the use of all possible methods of combating the tumor, and the choice is up to the oncologist, physician, radiologist, surgeon.
Basic is still considered surgery, and the amount of interference depends on tumor size and nature of its ingrowth into the surrounding tissue. In severe cases, surgeons have resorted to complete removal of the affected organ (stomach, uterus, lung), and in the early stages there is the opportunity to resect the tumor (mammary gland, liver, larynx).
Radiation and chemotherapy were not applicable in all cases, as different types of carcinomas have different sensitivity to this kind of influences. In severe cases these methods are designed to not only remove the tumor, how much to reduce the suffering of the patient, forced to endure severe pain and dysfunction of affected organs.
The prognosis of the presence of cancer is always serious, but in cases of early detection of cancer and timely treatment possible to completely get rid of the problem. In other stages of the disease the survival rate of patients decreases, there is a likelihood of cancer recurrence and metastasis. In order to treatment and prognosis was successful, you need time to see a specialist, and in the presence of precancerous lesions, increased risk of tumor development, adverse family situations, the patient must regularly undergo the relevant examinations and treatment to prevent the development of carcinoma.