Tumor brain symptoms
Mar 05, 2018
Brain tumor is an unusual proliferation of cells in the brain or in the membranes surrounding the brain. The most frequent brain tumors in adults are gliomas and meningiomas. Although brain tumors are heterogeneous and have a wide variation in age, on average most of the primary tumors occur at the age of 52-56 years. How to treat tumors with folk remedies look here.
Primary CNS tumors are in third place for mortality reasons aged 15 to 35 years and second in children under the age of 15 years.
Low-grade gliomas , such as oligodendroglioma, are found in young patients, whereas high-grade ones, such as glioblastoma multiforme, occur in older patients. In patients with multiform glioblastoma, the forecast is most unfavorable, the two-year survival rate is from 30% in patients younger than 20 years and up to 2% in patients older than 65 years. The average life expectancy in patients with glioblastoma is about 17 weeks without treatment and 62 weeks with radiation and chemotherapy.
Meningiomas are extragenital tumors, more common in older people, and their prognosis is relatively favorable( overall five-year survival is 81%, a five-year survival rate for meningosarcoma is 55%).The appearance of gliomas is somewhat more predisposed to men, to meningiomas - women.
Genetic lesions and abnormal gene expression play a major role in the development of gliomas. They trigger the overexpression of platelet-derived growth factor, which results in cell proliferation, glioma migration and inactivation of the TP53 gene, which normally inhibits the growth of abnormal cells. Patients with syndromes such as neurofibromatosis and tuberous sclerosis are much more likely to develop brain tumors. Only 2-10% of patients were genetically predisposed to brain tumors, and only 5% of gliomas could be hereditary.
The tumor increases intracranial pressure and thus presses the entire brain. This phenomenon is the cause of many symptoms associated with a brain tumor, both benign and malignant. Primary brain tumors occur directly in the brain, but they are observed much less frequently than secondary metastatic tumors that spread to the brain as a result of the development of cancer in any part of the body. The symptoms appear gradually and depend on which part of the brain is affected. Primary brain tumor is rare, accounting for only about 2 percent of all cancers.
Life factors can also play a role in the etiology of primary brain tumors. Previous radiation therapy is combined with factors such as diet and exposure to chemicals. There is no evidence of a clear connection between brain tumors and electromagnetic study or the use of mobile phones. There were studies that suspected a link between brain tumors and allergies.
Many genetic and life factors determine the development of primary brain tumors, although it is difficult to establish specific causes and connections. Epidemiological studies of brain tumors are difficult due to low incidence, clinical diversity and histological heterogeneity. In the future, molecular markers will probably help understand the etiology of brain tumors.
The variety of pathological processes underlying the bulk lesions of the central nervous system and the similarity of neurological symptoms to a certain extent limit the possibilities of clinical differential diagnosis. Therefore, the improvement of methods for early detection and differential diagnosis of tumors is one of the most urgent tasks of clinical neurooncology.
Due to the presence of various types of cells in the brain, the classification of brain tumors is complex. Attempts to classify tumors have been undertaken and are being undertaken continuously. Currently, the most commonly used classification developed by WHO in 1993 and supplemented in 2000.
The largest group of neoplasms of the brain unites neuroectodermal tumors( up to 60%).The largest proportion among them are tumors of the astrocytic series( 35-42%).Malignant forms of astrocyte prevail over benign( 1.3 times the male and 2 times among women).
According to the classification of tumors of the nervous system of WHO( Lyon, 2000) tumors of neuroepithelial tissue are divided into:
Vascular plexus tumors:
Glial tumors of unknown origin:
Neuronal and mixed neuronal glial tumors:
Most neuroepithelial tumors are gliomas. Gliomas account for 60% of all primary brain tumors. Malignant gliomas - glioblastoma multiforme and anaplastic gliomas( anaplastic astrocytoma, anaplastic oligodendroglioma and anaplastic oligoastrocytoma) are the most common infiltrative primary brain tumors. Histologically, they are subdivided into four degrees of malignancy, the different variants of which occur at different frequencies and differ according to the prognosis. The most common astrocytomas, oligodendrogliomas and glioblastomas.
Astrocytic tumors are combined as a common origin from astrocytic tissue, and a number of specific features: glial-fibrous component, growth pattern, frequent recurrence and malignancy, comparatively rare metastasis, even at high malignancy. According to domestic and foreign authors such tumors account for 55% of all neoplasms of the brain.
Astrocytomas by morphological structure are a heterogeneous group of primary brain tumors. Considering that astrocytomas develop from astroglia, along with division by histological stages of malignancy, a differentiation is made by the type of astrocyte( fibrillar or pilocity), underlying the proliferation. This division is of great prognostic importance, since pilocitic astrocytomas rarely malignant in contrast to fibrillar( infiltrative) astrocytes and can be almost completely removed. Diffuse astrocytomas account for 25-30% of hemispheric gliomas in adults. The age of the highest occurrence of supratentorial astrocytes is 20-50 years, which is generally 10 years lower than with glioblastomas. These tumors can develop in any part of the brain with a relatively lower incidence of occipital lobes. When the tumor is localized in the inferior parts, bilateral invasion can be noted. In the pathological process, both white and gray matter of the brain are involved. Benign astrocytomas have a better prognosis than malignant forms. The overall prognosis of such lesions is always unfavorable. Life expectancy with astrocytomas varies from 2.5 to 10 years. Moreover, it is known that about 10% of benign lesions over time are transformed into malignant forms.
50% of surgically treated benign astrocytes were transformed into anaplastic astrocytomas or glioblastomas. Progressive growth of fibrillar astrocytoma without anaplasia growth can also be observed.
The histological structure of tumors of the astrocytic series reflects the degree of their anaplasia. Typical astrocytomas are a group of tumors characterized by the lowest degree of anaplasia and the most benign course, including 3 main histological variants of astrocytomas: fibrillar, protoplasmic and mixed( fibrillar-protoplasmic).Division of diffuse gliomas at the stage of malignancy is an important point in the development of treatment tactics and in the subsequent prognosis. Some authors believe that it would be ideal to classify brain gliomas based on the presence or absence of malignant cells. Unfortunately, with the increase in anaplastic transformation in diffuse astrocytomas, both morphological and genetic heterogeneity is growing, which makes histopathological classification and separation at the stage problematic. In addition, the process of tumor development can not be static, since significant changes in the degree of malignancy can be detected over time. Traditionally, diffuse astrocyte gliomas are distributed according to the degree of malignancy from an astrocyte of a low degree of malignancy to glioblastomas.
The criteria of malignancy are the presence of nuclear and cellular polymorphism, proliferation of the vascular endothelium, the presence of mitoses and foci of necrosis.
A feature of fibrillar astrocytomas is their tendency to generate biologically more aggressive cells. This tendency of malignant change in fibrillar astrocytomas implies that some tumors can have both well-differentiated and anaplastic components. The presence of these components creates a problem of selecting material for the study, becauseif only well differentiated elements of the tumor get into the biopsy material, then this may interfere with the choice of adequate treatment.
A second important criterion in the treatment of fibrillar astrocytomas associated with the prognosis is the close relationship between patient age and life expectancy. Patients older than 60 years with anaplastic astrocytomas and glioblastomas have a significantly shorter life span, but this is also true for patients in this age group with well differentiated astrocytomas. Well-differentiated tumors are commonly found in humans in the 4th decade of life. The tumor has no clear boundaries and has infiltrative growth. Some of the hemispheric tumors have calcification sites, but this is more typical of oligodendrogliomas.
Macroscopically benign astrocytomas have a homogeneous character of the tumor tissue and are visualized as a node. The border of the tumor with the surrounding substance of the brain is clear.
Thus, the criteria for classifying brain tumors can be different: histological, tomographic, surgical, clinical, and prognosis. The purpose of neuroradiologic diagnosis is to distinguish a tumor from a non-tumor process, to accurately determine tumor localization, to characterize the structure of the tumor( solid, cystic structure), the presence of hemorrhages, necrosis, calcifications, and its vascularization. Based on these criteria, we can assume the most probable morphological nature of education and the prognosis of the disease.
In addition, four degrees are distinguished, where I-II reflects a low degree of malignancy, III-IV - high. Low-grade tumors include pilocitic astrocytomas and highly differentiated astrocytomas or oligodendrogliomas. High-grade tumors include anaplastic astrocytomas or anaplastic oligodendrogliomas, these tumors are classified as grade III according to the WHO classification. The most malignant( grade IV) are the multiform glioblastomas, which are the most frequent subtype and have the worst prognosis. Criteria for malignancy are the presence of nuclear and cellular polymorphism, the proliferation of endothelial vessels, the presence of mitoses and foci of necrosis.
High-grade gliomas( anaplastic astrocytoma and glioblastoma multiforme) can be classified as primary and secondary malignant astrocytomas. Primary malignant astrocytomas are typically found in older patients without a low-grade malignant tumor in history. These tumors are characterized by high expression of the receptors of abnormal epidermal growth factor( EGFR) and do not have a mutation of TP53.Secondary malignant astrocytomas usually occur in younger patients, come from a disintegrating primary low-grade malignant tumor. Low-grade gliomas can remain stable for many years. When they disintegrate, they are characterized by TP53 mutations and other genetic transformations.
Cells in these tumors are heterogeneous, more malignant cells grow faster, leading to an irregular form of tumors and different differentiation. Over time, they degenerate into tumors of a high degree of malignancy. Some of the molecular factors associated with tumor progression have already been discussed, for example, overexpression of platelet-derived growth factor, which causes cell proliferation, which is important in the early transformation of low-grade astrocytes into high-quality ones. Genetic damage is manifested in tumors of high degree of malignancy, in particular, in the loss of heterozygosity in chromosome 10q.
The rapid growth of glioblastomas in the first weeks after the onset of the disease leads to damage to the adjacent parts of the cerebral cortex and the appearance of neurological symptoms corresponding to the affected area. Changes in the brain tissue occur both from compression or germination of the tumor, and as a result of the damaging effect of toxic factors associated with the vital activity of tumor cells leading to the development of edema and necrosis of the cerebral cortex along the periphery of the tumor.
The delineation of tumors by the degree of malignancy is of key importance both in terms of prognosis of the disease, and for choosing a method of treatment. With tumors III-IV degree of malignancy, 50% survival is only 9-10 months, and for tumors of I-II degree, 50-75% of patients reach 5-year survival.
• Go through regular checks to detect cancer in any part of the body before it begins to spread.