Pediatric Astrocytoma
Introduction
Introduction to Pediatric Astrocytoma Astrocytoma is a benign glioma. It occurs in children with cerebellar hemisphere and is one of the common posterior fossa tumors in children. It grows slowly, has good differentiation, and has a good prognosis. Clinically, it is mainly caused by increased intracranial pressure and damage of one side of the cerebellar hemisphere. basic knowledge Sickness ratio: 0.002%-0.004% Susceptible people: children Mode of infection: non-infectious Complications: epilepsy hydrocephalus
Cause
Pediatric astrocytoma etiology
(1) Causes of the disease
There are two types of neuroepithelial tumors. One type is formed by the interstitial cells of the nervous system (ie, glial cells), called gliomas; the other type is formed by the parenchymal cells of the nervous system (ie, neurons), without a general name. Because of the pathogenic and morphological aspects, it is not yet possible to completely distinguish between these two types of tumors, and gliomas are often more common, so neuronal tumors are included in gliomas. Tumors of neuroepithelial origin are the most common intracranial tumors, accounting for approximately 44% of the total number of intracranial tumors.
(two) pathogenesis
Tumors were mostly located in the cerebellar hemisphere (56.6%), followed by the ankle (20.4%) and the fourth ventricle (19.5%), and a few were located in the cerebellopontine angle (3.5%). Tumor cystic changes are a prominent feature, accounting for 55.4% to 82% of cerebellar astrocytomas. Capsules can be expressed in two types: one is "sac in the tumor", that is, the tumor consists of single or multiple rooms. The wall of the capsule is a tumor tissue with unclear boundaries. The other is "tumor in the sac", that is, the tumor is a nodular tumor nodule in a large cyst, while the remaining wall is a glial proliferative zone that is not a tumor tissue. The cyst fluid is mostly yellow clear liquid, about 20 ~ 40ml, high protein content, self-coagulation in vitro (Froin sign positive). Tumors rarely have necrosis and hemorrhage, and some lesions can be calcified. Cerebellar astrocytoma is mostly composed of well-differentiated fibrillar astrocytes, but also hairy cell astrocytoma. Cerebellar hair cell astrocytoma is characterized by similar tumor characteristics in the shape of the funnel, and most of the tumor cells are fusiform. It is rich in collagen fibers and the collagen fibers are thickened or clumped to change the pathological features of cerebellar astrocytoma.
Prevention
Pediatric astrocytoma prevention
1. Avoid harmful substances (promoting factors)
It is able to help us avoid or minimize exposure to harmful substances.
Some related factors of tumorigenesis are prevented before the onset, and many cancers can be prevented before they are formed. A report in the United States in 1988 compared the international malignant tumors in detail and proposed many external factors of known malignant tumors. In principle, it can be prevented, that is, about 80% of malignant tumors can be prevented by simple lifestyle changes, and traced back. In 1969, Dr. Higginson's research concluded that 90% of malignant tumors are caused by environmental factors," "Environmental factors", "lifestyle" refers to the air we breathe, the water we drink, the food we choose to make, the habits of activities, and social relationships.
2. Improve the body's immunity against tumors
Can help to strengthen and strengthen the body's immune system and cancer.
The focus of our current cancer prevention efforts should first focus on and improve those factors that are closely related to our lives, such as quitting smoking, eating properly, exercising regularly, and losing weight. Anyone who follows these simple and reasonable lifestyles can Reduce the chance of cancer.
The most important thing to improve the function of the immune system is: diet, exercise and control troubles. Healthy lifestyle choices can help us stay away from cancer. Maintaining good emotional state and proper physical exercise can keep the body's immune system at its best. Tumors and prevention of other diseases are equally beneficial. Other studies have shown that appropriate activities not only enhance the body's immune system, but also reduce the incidence of colon cancer by increasing the peristalsis of the human intestinal system. Here we mainly understand the diet in preventing tumorigenesis. Some questions.
Human epidemiology and animal studies have shown that vitamin A plays an important role in reducing the risk of cancer. Vitamin A supports normal mucosa and vision. It directly or indirectly participates in most of the body's tissue functions. Vitamin A is present in animal tissues. In the liver, whole eggs and whole milk, the plant is in the form of -carotene and carotenoids, which can be converted into vitamin A in the human body. Excessive intake of vitamin A can cause adverse reactions in the body and -carrot This is not the case with carotenoids, and the low vitamin A content in the blood increases the risk of malignant tumors. Studies have shown that those with low levels of vitamin A intake in the blood increase the likelihood of lung cancer, while those with low blood levels in smokers Levels of vitamin A ingestors have the potential to double lung cancer. Vitamin A and its mixture can help remove free radicals in the body (free radicals can cause damage to genetic material), and secondly stimulate the immune system and help differentiate cells in the body. Ordered tissue (while the tumor is characterized by disorder), some theories suggest that vitamin A can help early carcinogens Invasion mutated cells become reversed the occurrence of the normal growth of cells.
In addition, some studies suggest that supplementation with -carotene alone does not reduce the risk of cancer, but rather increases the incidence of lung cancer. However, when -carotene binds to vitamin C, E and other antitoxin substances, its protective effect. It is shown, because it can increase free radicals in the body when it is consumed by itself. In addition, there are interactions between different vitamins. Both human and mouse studies have shown that the use of -carotene can reduce 40% of vitamins in the body. At E-level, a safer strategy is to eat different foods to maintain a balanced vitamin to protect against cancer, as some protective factors have not been discovered so far.
Vitamin C, E is another anti-tumor substance that prevents the harm of carcinogens such as nitrosamines in food. Vitamin C protects sperm from genetic damage and reduces the risk of leukemia, kidney cancer and brain tumors in their offspring. Vitamin E can reduce the risk of skin cancer. Vitamin E has the same anti-tumor effect as vitamin C. It is a scavenger that protects against toxins and scavenges free radicals. The combination of vitamins A, C and E protects the body against toxins. Better than applying it alone.
At present, research on phytochemistry has attracted widespread attention. Phytochemistry is a chemical found in plants, including vitamins and other substances found in plants. Thousands of plant chemicals have been found, many of which have anticancer properties. The protective mechanism of these chemicals not only reduces the activity of carcinogens but also enhances the body's immunity against carcinogens. Most plants provide antioxidant activity that exceeds the protective effects of vitamins A, C, and E, such as a cup of cabbage. Contains 50mg of vitamin C and 13U of vitamin E, but its antioxidant activity is equivalent to the antioxidant activity of 800mg of vitamin C and 1100u of vitamin E. It can be inferred that the antioxidant effect in fruits and vegetables is far better than what we know. The effect of vitamins is strong, and no doubt natural plant products will help prevent cancer in the future.
Complication
Pediatric astrocytoma complications Complications, epileptic hydrocephalus
In the advanced stage, there may be a "cerebellic crisis". 60% of astrocytomas in the cerebral hemisphere have symptoms of epilepsy, and cerebellar astrocytoma has early symptoms of increased intracranial pressure caused by obstructive hydrocephalus.
Symptom
Symptoms of pediatric astrocytoma Common symptoms Coercive head increased intracranial pressure, localized signs, unclear, unstable tremor balance dysfunction
The disease progresses slowly, the average course of disease is about 2 years, and some can last up to 10 years. The symptoms vary from site to site. Most of them have localized signs and symptoms caused by direct destruction of the tumor. Later, symptoms of increased intracranial pressure may occur. It is a symptom of increased intracranial pressure and damage of one side of the cerebellar hemisphere. The latter is awkward movement of the affected limb, the upper limb is more serious than the lower limb, and the performance is unstable. It cannot be a button and a fine movement disorder such as eating with a spoon, affecting the cerebellum There may be a balance disorder. More than 70% of the children may have large nystagmus. When the cerebellar damage is severe, there may be cerebellar language (unclear or explosive language). The child may have lower muscle tone and tendon reflexes. 1/7 has a forced head position, and a "cerebellic crisis" can occur in the late stage.
Examine
Pediatric astrocytoma examination
General routine examination has no specific performance, and diagnosis mainly depends on auxiliary examination.
1. The skull X-ray film showed signs of increased intracranial pressure. When the tumor was located on the surface of the cerebellum, it showed thinning and erosion of the occipital scaly, and 4.3% of the tumor had calcified plaque.
2. CT examination can be seen in the low-density space of the cerebellar hemisphere and midline, astrocytoma grade I is not enhanced, II-III grade can be unevenly enhanced, and some tumors show high density of multiple low-density lesions (ie, capsules) Intratumor), some are high-density nodules on the inner wall of the low-density capsule (ie, the tumor is inside the capsule).
3. MRI is the abnormal signal of T1 long T2 in the posterior fossa, and the cyst fluid is different from cerebrospinal fluid due to the high content of protein components.
Diagnosis
Diagnosis and diagnosis of pediatric astrocytoma
The course of the disease progresses slowly, and one side of the cerebellar damage sign appears on the basis of increased intracranial pressure. The possibility of cerebellar astrocytoma should be considered first.
Need to pay attention to the identification of cerebellar vascular reticuloma: the latter image also shows cystic space in the cerebellar hemisphere containing tumor nodules, the enhancement is more obvious than astrocytoma, the incidence in children is extremely low, Accompanied by congenital multiple organ cysts, erythrocytosis and retinal vascular lesions, a few family history, digital subtraction angiography (DSA) can be seen in the deformed vascular mass.
