Pediatric pheochromocytoma
Introduction
Introduction to pediatric pheochromocytoma Pheochromocytoma (pheochromocytoma) originates from the adrenal medulla, sympathetic ganglia, parasympathetic ganglia or other parts of the pheochromic tissue, so it can occur from the cervical sympathetic chain to the pelvic region, these cells produce vasoactive amines . Adrenalin is produced only in the adrenal medulla and the tissues of the aorta (organs of Zuckerkandl), while the norepinephrine is produced in the sympathetic chain tumors. The majority of children with pheochromocytoma operate about 4 to 6 cm, and the cut surface is Brownish yellow to light brown, completely surrounded by compressed normal adrenal tissue, with areas of hemorrhage or cystic necrosis. Microscopic examination is difficult to identify as benign or malignant, mainly based on clinical, if there is recurrence or metastasis, it is considered malignant, rarely malignant in children, but more adrenal lesions than adults, accounting for about 30%, common parts It is the aortic bifurcation and the aorta. Most of the deaths occurred during and immediately after surgery because no second tumor was found. Another feature of pheochromocytoma in children is that there are more family hereditary and multiple endocrine tumors. basic knowledge The proportion of illness: 0.0035% Susceptible people: children Mode of infection: non-infectious Complications: congestive heart failure, hematuria
Cause
Causes of pheochromocytoma in children
(1) Causes of the disease
The cause of the disease is still unclear, and is directly related to the development and growth of neuroectodermal cells. Some pheochromocytoma are related to genetic factors, and often accompanied by other diseases, such as multiple endocrine tumors, multiple neurofibromas, and atherosclerosis. , Sturge-Weber syndrome, von Hippel-Lindau disease, etc.
(two) pathogenesis
Pheochromocytoma is mostly benign, mostly single or multiple, the tumor is round or oval, the surface is smooth, there is a complete capsule, the surrounding blood vessels are rich, the diameter is generally 2 ~ 6cm, and the weight is more than 100g. However, if there is a large volume, the tumor cells are large under the microscope, the shape is irregular, the granules are more granules, and can be stained by dichromate. The pheochromocytoma is good and the malignant single can not be identified from the morphology. It can be diagnosed as malignant by extensive infiltration of adjacent organs or tissues and metastasis in organs and tissues that are normally free of chromaffin cells.
Prevention
Pediatric pheochromocytoma prevention
The cause of the disease is still unclear. Understanding the risk factors of tumors and formulating corresponding prevention and treatment strategies can reduce the risk of tumors. There are two basic clues to prevent tumors. Even if tumors have begun to form in the body, they can help the body to improve resistance. Force, these strategies are as follows:
1. Avoid harmful substances (promoting factors): It can help us avoid or minimize exposure to harmful substances.
2. Improve the body's immunity against tumors: Can help to strengthen and strengthen the body's immune system and cancer.
(1) Avoid harmful substances: Some related factors of tumorigenesis are prevented before the onset of the disease. About 80% of malignant tumors can be prevented by simple lifestyle changes. The focus of cancer prevention and treatment work we are currently facing should be the first focus and Improve factors that are closely related to our lives, such as quitting smoking, eating properly, exercising regularly, and losing weight. Anyone who follows these simple, reasonable lifestyles can often reduce their chances of developing cancer.
(2) Promote the body's immunity: The most important thing to improve the function of the immune system is: diet, exercise and healthy lifestyle, maintaining a good emotional state and appropriate physical exercise can make the body's immune system at its best, for prevention It is also beneficial to have tumors and prevent other diseases.
Complication
Pediatric pheochromocytoma complications Complications, congestive heart failure, hematuria
Can cause visual impairment, convulsions or mental illness, polydipsia, polyuria, hypertensive heart disease and congestive heart failure, hyperglycemia and diabetes, a small number of patients with hematuria, and often with multiple endocrine tumors, multiple nerve fibers Tumor, sclerosis, Sturge-Weber syndrome, von Hippel-Lindau disease, etc.
Symptom
Symptoms of pheochromocytoma in children Common symptoms Loss of nausea, abdominal pain, palpitations, polyuria, high blood pressure, diabetes, hematuria, convulsions
The clinical symptoms are caused by excessive adrenaline and norepinephrine in the blood circulation. Because of the different secretion of the two hormones, the clinical manifestations of each case are also different. Hypertension is a characteristic of this disease, which can be as high as 21.3~26.7/14.7~112.0kPa. (160200/11090mmHg), more than 90% are persistent hypertension, a few are paroxysmal hypertension (50% in adults are paroxysmal), and there are also persistent and bursting episodes. Infrequent seizures, gradual seizures, some from paroxysmal to persistent, accompanied by headaches, palpitations, sweating, paleness, nausea, vomiting and abdominal pain, etc., can be completely relieved during the episode, sometimes due to Some postures such as lying on the side or flexing the body, or pressing the abdomen or kidney area cause high blood pressure, however, children often hospitalize with neurological symptoms such as headache, visual impairment, convulsions or mental illness, sometimes misdiagnosed as brain tumors, There are also symptoms of weight loss and polydipsia, polyuria, polydipsia, polyuria can be caused by a lot of sweating, and because catecholamines have the effect of inhibiting vasopressin, persistent high blood pressure makes the heart hypertrophy. It has obvious left ventricular hypertrophy, which leads to hypertensive heart disease and congestive heart failure. There are optic disc edema, hemorrhage and small arterial spasm in the fundus. The child can have hyperglycemia and diabetes, abnormal glucose tolerance curve, basal metabolism. Rates tend to increase, and metabolic abnormalities are particularly pronounced in those tumors that secrete adrenaline.
A small number of pheochromocytoma occur in the bladder. The tumor is often not too large. It is located in the muscular layer and is covered with normal bladder mucosa. The clinical features are symptoms of high blood pressure and other catecholamines when the bladder is inflated or urinating. The patient has hematuria.
Examine
Examination of pheochromocytoma in children
1.24h urine catecholamine (CA) and metabolite determination
3Methoxy-4hydroxymandelic acid (VMA) is the final metabolite of catecholamine. The normal value is different in each laboratory, generally 11 ~ 35mol / 24h (2 ~ 7mg / 24h), pheochromocytoma patients are significantly elevated, high The blood pressure can be more than 2 times when the attack occurs. In normal people, norepinephrine (NE) excretion is <885nmol/24h, and adrenaline (E)<273nmol/24h. The pheochromocytoma can be significantly increased when hypertensive episodes occur. More than 2 times has diagnostic value, and 3-methoxy norepinephrine is also significantly increased.
2. Blood CA determination
In patients with pheochromocytoma, the increase of blood CA is more common in NE, followed by NE and E, and the elevated plasma CA in resting position has diagnostic value.
3. methoxynorepinephrine
Sensitivity and specificity, malignant metastatic pheochromocytoma, plasma catecholamines can be normal, but methoxynorepinephrine is often elevated.
4. Drug experiment
The drug experiments include excitation experiments and block experiments. Due to the development of various inspection methods, and the excitation experiments have certain risks, they are rarely used at present.
(1) Excitation experiment: suitable for non-seizure period of blood pressure below 21.3/13.3 kPa (160/100mmHg), intravenous injection of histamine phosphate 0.030.14mg, intravenous glucagon 0.51mg or tyramine 1mg If the blood pressure rises above 8/5 kPa (60/40 mmHg), it is positive. This experiment has certain risks. Prepare benzyl oxazoline in advance, in case of high blood pressure.
(2) Blocking test: It is suitable for blood pressure of 22.7/14.7kPa (170/110mmHg) or above, when intravenously injected with benzyl oxazoline 5mg, blood pressure drops over 4.7/3.3kPa within 3~5min (35/ 25mmHg) was positive, and clonidine inhibition assay was also used to determine the inhibition of plasma catecholamines.
5. Imaging examination
(1) B-mode ultrasound examination: the diagnosis of adrenal tumors is more accurate, but the tumors outside the adrenal gland are not good.
(2) CT and MRI: The accuracy of CT diagnosis of adrenal tumors is more than 90%. MRI and CT are similar, and it is beneficial to find pheochromocytoma and multiple tumors outside the adrenal gland.
(3) 131I-meta-iodo-benzylguanidin (131I-MIBG) scintigraphy: it can be used for metastasis imaging of pheochromocytoma and malignant pheochromocytoma, both localization and qualitative Specific and sensitive, the accuracy rate is above 90%.
Diagnosis
Diagnosis and diagnosis of pheochromocytoma in children
diagnosis
Children with hypertension in addition to medical history and physical examination, must be used for urine routine, urine culture, serum creatinine, urea nitrogen determination and intravenous urography, the most commonly used catecholamine metabolism test is to measure VMA, if the abnormal results should consider pheochromocytoma, The most important positioning tests are abdominal ultrasound and CT.
Differential diagnosis
Different from essential hypertension and renal hypertension, there are headache, visual impairment, convulsions and brain tumors.
The differential diagnosis of pheochromocytoma also needs to be differentiated from some diseases with sympathetic hyperactivity and/or high metabolic status:
1. Coronary heart disease angina pectoris;
2. Anxiety caused by other reasons;
3. Unstable essential hypertension;
4. Diseases with paroxysmal hypertension, such as brain tumors;
5. Menopausal syndrome;
6. Hyperthyroidism.
