Pediatric germ cell tumor
Introduction
Introduction to pediatric germ cell tumor Germcelltum is a group of tumors formed by the differentiation, maturation and migration of primitive pluripotent germ cells. The primary site and clinical manifestations are different and can be seen in children of all ages. basic knowledge The proportion of illness: 0.005% Susceptible people: children Mode of infection: non-infectious Complications: anemia
Cause
Pediatric germ cell tumor etiology
(1) Causes of the disease
Germ cell tumors can occur in any normal or different gonads of the original gonads. The migration of normal primordial gonads often follows the central axis of the body. Therefore, most of the germ cell tumors occur in the midline except for the ovaries and testes. The cause is unclear.
(two) pathogenesis
1. The tissue origin of germ cell tumors
At the 4th week of embryonic development, undifferentiated, gender-deficient embryonic gonads were observed in the yolk sac area. Thereafter, the original gonads migrated from the yolk sac to the genital ridge of the posterior peritoneum, and were regulated by sexual chromosome information to mature into the ovary or testis. Gradually descend to the pelvic cavity, scrotum, primordial gonads can occur in different displacement lines, such as migration to the pineal gland, mediastinum, posterior peritoneum, appendix, etc., so germ cell tumors can occur in any normal or different gonads of the original gonads In addition to the origin of the ovary and testis, most of the germ cell tumors occur in the midline, the origin of germ cell tumors.
2. Histological classification
The histological classification of gonad and extragonadal germ cell tumors in children is as follows.
(1) Ovarian origin:
1 germ cell sex: asexual germ cell. Endodermal sinus tumor (yolk sac tumor). Teratoma (mature, immature, malignant). Embryonic cancer. Malignant mixed germ cell tumor. Multiple embryos. Choriocarcinoma. Gonadal blastoma.
2 non-germ cell: epithelial tumor; sex cord-stromal tumor.
(2) Testicular origin:
1 germ cell: endodermal sinus tumor (yolk sac tumor). Teratoma (mature, immature, malignant). Embryonic cancer. Gonadal blastoma. Others such as malignant mixed germ cell tumor, seminoma, choriocarcinoma.
2 non-germ cell sex: sex cord-stromal tumors.
(3) extragonadal germ cell tumor: teratoma (tail, mediastinum, posterior peritoneum, pineal gland, etc.): +/- yolk sac tumor components; +/- embryonic cancer components.
3. Pathological features
(1) Different parts of germ cell tumors are consistent in pathology: the same type of germ cell tumors have the same pathological morphology in different parts of the gonads and outside the gonads.
(2) Both benign and malignant components are included: tumors can contain both benign and malignant components, and their malignant components determine its clinical features. Different parts of the same tumor have different cellular components, so multi-level pathological sections are needed to avoid diagnostic errors. .
Prevention
Pediatric germ cell tumor 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.
Promote the body's immunity against 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, maintain good emotional state and appropriate physical exercise can make the body The immune system is at its best, and it is also good for preventing tumors and preventing other diseases. In addition, 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 some of the problems of diet in preventing tumors.
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 germ cell tumor complications Complications anemia
The pathogenesis of this disease is more common, more common in the appendix, testis, ovary, pelvic, posterior peritoneum, mediastinum and intracranial. Different sites of the disease have different clinical manifestations, and often come to the clinic because of the symptoms of oppression and mass or enlarged mass. When the tumor originates in the appendix or pelvis and compresses the rectum and urinary tract, changes in bowel habits occur, and the appearance of the appendix changes or is asymmetrical, often suggesting that there may be a lump in the appendix. Complications are common in the development of various compression symptoms of the tumor, ovarian mass torsion can cause acute abdominal pain, advanced tumors appear systemic symptoms, such as weight loss, fever, anemia, chest and ascites.
Symptom
Pediatric germ cell tumor symptoms Common symptoms Abdominal circumference increases abdominal pain cystic mass
Germ cell tumors can occur from birth to adolescence, but in infants and young children, the incidence of preschool age is more common. The pathogenesis of this disease is more common, more common in the appendix, testis, ovary, pelvis, posterior peritoneum, mediastinum. And intracranial, different clinical sites have different clinical manifestations, often due to sputum and lumps or enlarged masses to produce compression symptoms, when the tumor originated in the appendix or pelvic cavity and oppress the rectum and urinary tract, the size Habitual changes, the appearance or asymmetry of the appendix, often suggest that there may be a lump in the appendix, the testicular mass is easier to find early, the testicular asymmetry is swollen, hard, the posterior peritoneum and ovarian mass are asymptomatic and difficult to find early, often in The abdomen circumference is increased or the abdomen and abdomen are seen. The ovarian mass can be reversed due to acute abdominal pain. The primary mass in the mediastinum can compress the blood vessels or the trachea, resulting in superior vena cava compression syndrome and respiratory compression symptoms.
Examine
Pediatric germ cell tumor examination
Laboratory inspection
Blood
Chorionic gonadotropin, alpha-fetoprotein and carcinoembryonic antigen in the blood of patients can be elevated. It can return to normal after surgery and rise again when recurring or spreading. 11 cases of germ cell tumors were reported abroad, and all patients had elevated blood levels of chorionic gonadotropin or alpha-fetoprotein. Therefore, most scholars believe that patients with elevated chorionic gonadotropin or alpha-fetoprotein before surgery have a poor prognosis.
2. Cerebrospinal fluid
The pressure of most patients increased, and the protein content of cerebrospinal fluid in some patients was mildly moderate, and the chorionic gonadotropin or alpha-fetoprotein in cerebrospinal fluid was significantly increased. Cystic cells can sometimes be found in cerebrospinal fluid cytology. Epithelioid cells can occur in cerebrospinal fluid in 70% of cases, but do not necessarily mean spinal cord metastasis.
Film degree exam
1. Skull flat film
Both can show signs of increased intracranial pressure. 40% to 60% of patients may have abnormal calcification of pineal gland, especially when calcification occurs in children aged 10 to 15 years, calcifications are more than 1 cm in diameter, and calcification is displaced downwards and backwards, which is a powerful method for diagnosing germ cell tumors. evidence.
2. Radionuclide scanning
Continuous brain scintillation tomography scans, the vast majority of nuclide accumulation in the tumor can be seen, the diameter is greater than 1.5cm.
3.CT scan
CT scans accurately determine the size, location, and surrounding relationships. Plain CT can be seen with the same density or slightly higher density of gray matter, and the chance of calcification of germ cell tumor in pineal region is much higher than that of sellar cell tumor in sellar region. When the calcified pineal gland (in the form of a pellet) is sometimes surrounded during the growth of the pineal region germ cell tumor, the calcified "shot" may be in the tumor, or in the periphery of the tumor, often on the side. Or rear, even can be pushed to the front. The shape of the tumor is round, irregular or butterfly-shaped, and the latter has a characteristic value in the diagnosis of germ cell tumors. The normal human pineal calcification rate is about 40%, and the pineal calcification rate of patients with germ cell tumor is nearly 100%; the saddle upper germ cell tumor can be free of calcification or fine calcification.
Enhanced CT: When CT scans are found, the CT should be injected immediately for CT intensive scanning, showing moderate to obvious uniform enhancement, and a few enhancements are uneven, showing smaller cystic changes. Therefore, children or adolescents, CT found a slightly higher density of pineal body area, uniform injection of drugs (a few can be uneven), if there is bullet-like calcification, it is strongly suggestive of germ cell tumor. The saddle-top germ cell tumor is located in the midline funnel and/or pituitary gland into the saddle, and it is not uncommon to invade the neurohypophysis. The saddle upper germ cell tumor can be round or lobulated, and the CT scan and enhancement are similar to the pineal region, but some scholars have pointed out that there is little calcification in the germ cell tumor at this site. In addition to the above-mentioned "single-on" tumors, with regard to "multiple" germ cell tumors, the most typical is the discovery of 2 or 3 germ cell tumors at the time of CT examination. CT examination is of great value for germ cell tumors, especially for the calcification of the tumor and the enlargement or displacement of the ventricles. Different subtypes of germ cell tumors have their own unique manifestations, sometimes combined with clinical, and even qualitative diagnosis of tumors.
4.MRI examination
MRI is very clear on small germ cell tumors (diameter <1cm) or spinal cord metastases in the saddle; it shows that the germ cell tumors in the pineal region are often round, elliptical or irregular, and most T1 are equal or slightly lower signals. T2 is a slightly higher signal, and a few can also be equal signals; uniform enhancement after injection, clear boundaries, and sometimes only a few moderate or uneven enhancement. It has been reported that 20% to 58% of germ cell tumors have small cystic changes. These capsules are caused by protein liquid or necrotic liquefaction, usually very small, sometimes with small hemorrhage in the tumor, and high signal in T1. The pineal region can invade the midbrain and the thalamus, and there is a blurry high signal on the T2 image. MRI showed comprehensive coverage of tumor implantation or dissemination, except for the multiple lesions of T1 and T2 images, which showed clear lesions and marked enhancement after injection. The ganglion germ cell tumor is also T1 or the like, and T2 is slightly higher signal. It can be evenly strengthened after injection, and some show atrophy in the ipsilateral cortex.
Diagnosis
Diagnosis and diagnosis of pediatric germ cell tumor
diagnosis
The diagnosis can be confirmed based on clinical manifestations and laboratory and auxiliary examination results.
Differential diagnosis
1, craniopharyngioma: mostly cystic or cystic solid mass, calcification is more common. Pure nature can be slightly higher density, and can be strengthened, and is difficult to identify with germ cell tumors.
2, astrocytoma: the general tumor is larger, the density is lower, the latter can be bleeding, the tumor is usually located in the hypothalamus, and extending along the optic chiasm or the visual beam, can form a mass in the eyelid.
3, pituitary tumor: occurs in the saddle, but can grow on the saddle, children are rare, the tumor is easy to hemorrhage, necrosis, saddle bottom bone thinning, subsidence, cavernous sinus often involved.
4, meningioma: occurs in adults, children are rare, the tumor site is partial, with bone hyperplasia, sclerosis and sphenoid sinus excessive gasification.
