May
08
23:01
Malignant tumors

Pheochromocytoma

Pheochromocytoma

pheochromocytoma photo Pheochromocytoma - a tumor of the adrenal gland, which is formed from chromaffin tissue and produces substances of biological origin (dopamine, epinephrine, norepinephrine).Quite often pheochromocytoma occurs in people 25 to 50 years who have one of the main reasons this disease - high blood pressure.

adrenal tumors are classified into types such as bilateral and multiple.They can be combined with giperparatirozom and thyroid cancers.For pheochromocytoma typical autosomal dominant pattern of inheritance.

causes Pheochromocytoma Pheochromocytoma

takes among pathologies of the endocrine glands leading role.At the moment, there are significant advances in the study of adrenal pheochromocytoma, but many things that are related to the causes, pathology, physiology and biochemistry, largely remain unclear.

Pheochromocytoma formed from chromaffin tissue is very rare in a ratio of 1: 10000.This figure increases when detecting pheochromocytomas in patients suffering from hypert

ension.Basically it is found at post-mortem studies at autopsy, since there are obvious difficulties in its diagnosis.The absence of all clinical spectrum of disease or existing asymptomatic pheochromocytoma often lead to incorrect diagnosis.

In 8% of cases show a familial pheochromocytoma, which are associated with diseases such as Cipla's syndrome, a disease Hippell-Lindau disease and Recklinghausen.

mainly (75% of cases) pheochromocytoma localized in any one adrenal gland, usually - in the right.In 10% of cases, it is found in both, and 15% - is the adrenal glands.Pheochromocytoma, which had already been diagnosed and removed, can produce a relapse.

pheochromocytoma in children is more common in the form of bilateral or family extraadrenal form.This type of neuroendocrine disease is not considered to be completely benign tumors, as a tumor able to metastasize to many internal organs, muscles, lymph nodes, the lungs and even the brain.

Pheochromocytoma symptoms

in hemodynamics adrenal pheochromocytoma mark dangerous violations.For the clinical picture of the disease is characterized by three types of flow - paroxysmal, permanent and mixed.The cardinal feature that depends on the activity of tumor and secretion can occur episodic or constancy is hypertension.

paroxysmal form of pheochromocytoma can occur with a sharp and sudden increase in blood pressure to very high numbers.During this period, patients may complain of headache, pulsating character, dizziness, heart palpitations, a sense of danger arises for life.Skin becoming pallor, sweating, and there is a strong tremors, marked chest pain and abdominal pain, breathing becomes frequent and labored, disturbed vision, increased body temperature.Sometimes shin muscles cramp, nausea, and vomiting and then.This form of pheochromocytoma flow occurs most often (about 40-80%).It increased sweating, palpitations and headache, then there are three clinical symptoms, are mainly found in most patients.Usually catecholamine crisis could trigger a rich food intake, physical activity, injury, childbirth, and even urination.Duration of pheochromocytoma attack can last up to several hours.

At constant clinical forms of pheochromocytoma is always present high blood pressure, which is very similar to essential hypertension.A mixed form is manifested in the appearance of crises constantly elevated pressure.

During very heavy pheochromocytoma crisis, the pressure that fails to stabilize the disease is characterized by uncontrollable.Such a condition of the patient is called catecholamine shock, which manifests itself in 10% of patients, particularly in children.

The examination of the patient having great difficulty in diagnosis due to the variability of symptoms, the possibility of an atypical course of the disease and the available "masks" in the clinical picture.Under such masks are often misdiagnosed.They can become a heart attack, thyrotoxic crisis, stroke, toxemia of pregnancy, renal disease, and others.

Pheochromocytoma diagnosis

basic material for the diagnosis of pheochromocytoma is a catecholamine secretion.In a study taken daily urine test, which measured the content of physiologically active substances.Ekskretsionny method of investigating the accuracy reaches 96%.In addition, blood sampling is done more on neurotransmitters and hormones, which determine the amount of dopamine, epinephrine, norepinephrine.

sometimes to clarify the affected side of the tumor, a study of catecholamines, blood is taken from the cubital vein (left or right).One of accurate methods of diagnosis of pheochromocytoma is to study excretion immediately after a hypertensive crisis.It is believed that this method of diagnosis is only 25% false positive results.The possibility of taking blood for re-analysis to determine the catecholamines, said about the advantages of this method of research.

To detect catecholamines in urine, take a long time.No studies will depend on the activity of the secretory function of the tumor as it might not be constant.

For the diagnosis of pheochromocytoma is necessary to determine the exact values ​​of adrenaline and noradrenaline.If they are much too high, you can argue about the existence of a pheochromocytoma of the adrenal gland and too low - false-negative result.The most accurate measure is available noradrenaline patient plasma or urine.

to diagnosis had increased efficiency, using pharmacological tests.For this use certain drugs that stimulate tumor and release catecholamines or conversely, block their peripheral action.Such pharmacological tests are more conventionally called, some provocative, and others - is suppressed.By provoking group includes insulin, histamine, tyramine, epinephrine, metilatsetilholin, and the vast - phentolamine, clonidine.

If all laboratory tests and clinical picture confirmed kateholaminoobrazovanie, then you can proceed to the next stage of the diagnosis - topical.This method allows the study to determine adrenal or outside the presence of pheochromocytoma.For this purpose, the radioactive metayodbenzilguanidin which selectively accumulates in affected cells of the adrenal catecholamines.

One of the modern methods of diagnosis of this tumor is considered MRI.But CT is sensitive to a given tumor 95-100%.Ultrasound diagnostic accuracy in respect of the disease ranges from 80 to 90%.Obese people see the adrenal glands on ultrasound is very difficult.In recent years, the definition of tumors were extensively fine-needle puncture biopsy, using ultrasound or CT scan.But such research methods as a radiographic tomography, aortography, intravenous urography are used rarely.Best results in the evaluation of adrenal achieved using venography, during which a catheter is used to introduce it into the central vein.

Pheochromocytoma treatment

One of radical treatment of tumors that are caused by hormones and their activity is the production of the removal of pheochromocytoma.

main objective of the whole preoperative preparation is to stabilize the patient's hemodynamics.And for this it is necessary to regulate blood pressure drugs such as Tropafen, phentolamine, Dibenzilin.The scheme of the latter can be different and chosen strictly individually.Assign it with 10 mg 2-3 times a day, and then the dose is increased by 20-40 mg indications to achieve a positive effect.

when the patient shows orthostatic reaction of nature in response to changes in your body position, it is considered a criterion for the effective treatment of pheochromocytoma.An important indicator of orthostatic hypotension is considered blood pressure, which should not be less than 80/45 mm Hg.Art.and rise above 160/90 mm Hg.Art.In order to stabilize the pressure of patients with hypertension in mixed form, Katapressan administered in a dosage of 0.15-0.3 mg three times a day, Raunatin - 2-3 also Apressin mg - 25 mg 4 times / day.These drugs can not prevent the occurrence of hypertensive crises, but basically stabilize this pressure mezhkrizovy period.Always important to remember all of these drugs can cause a collapse, even hyperfunction of the adrenal glands.

But Medications like Terazolin, Prazolin, Doksazolin, highly selective.Therefore, they are also prescribed individually.

in paroxysmal pheochromocytoma when hypertensive crises are rare, used nifedipine, verapamil, diltiazem, and others. They gradually reduce blood pressure and prevent crises.

To prepare the surgical approach to the pheochromocytoma, an important point is considered to ensure free manipulation of the wound that had greater access to the tumor.This is necessary due to the overproduction of catecholamines in tumors, which prevents the slightest pressure on it.

To reduce giperkateholaminemii resorted to the synthesis of physiologically active substances of the pheochromocytoma using drug-Metilptirozina and that almost 80% reduction in the content of these substances in the adrenal glands.Initially prescribed daily dose of 500-1000 mg, and then increase it to 4gr.This drug can sometimes cause serious deviations.In patients with marked mental disorders and extrapyramidal disorders, diarrhea, and changes in the gastrointestinal tract.

good positive results in treating drug and pheochromocytoma gives Metilparatirozin, which blocks the synthesis of catecholamines and they thus hardly enter the bloodstream.A Metilparatirozin appointed on 500-2000 mg per day, helping without complications for the patient's health to carry out the operation to remove the tumor, fully eliminating giperkateholaminemii.

To remove pheochromocytoma can be used different methods of surgery.These include both transbryushinnoe, extraperitoneal, transthoracic and combined.

Sometimes after the operation is attained a positive trend, ie blood pressure remains high.This may be reasons related to the wrong surgery.You may also receive and hypotension as a result of bleeding or inflammation of the BCC.

Deleting multiple forms of pheochromocytomas is carried out in several stages.If it is impossible

excision of a malignant tumor, its recurrence or when it has multicentric growth may surgical removal of only part of it, to reduce the functioning tissue and thereby reduce the level of circulating catecholamines.

Radical treatment of pheochromocytoma almost always gives absolute cure many patients.But as a result of long giperkateholaminemii, there are changes in SSSand kidney, indicating the preservation of many symptoms that were preoperatively.But the appointment of necessary medicines regulate blood pressure.

The most important result for the patients remains after surgery, which may make available or missing, at the moment, metastases.Because the features which relate to cancer, for example, capsules or germination angioinvaziya give little chance for recovery.

So only operative surgical treatment of pheochromocytoma can help patients, but about 8% of cases, the disease gives relapses.And basically the prognosis is favorable, if not detected during the operation metastases distant character.

All patients who underwent surgery to remove the pheochromocytoma, are on constant medical observation.

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