pheochromocytoma
catecholamine excreting tumor
98% in abdomen
majority in adrenal gland
same biochem result with benign tumor
local invasion or metastasis
25 % familial
Sx vs. incidentaloma vs. familial
MEN2 -
FHx
VHL
von recklinghausen
classic presentation
palpitation, headache, episodic diaphoresis
hypersecretion of NE, Epi, DA
Synthesis of Catecholamine from Tyrosine
Sx(symptomatic), HTN(hypertension), DM(diabetes)
biochemical tests
24 urine catecholamine
metanephrine
MIBG test
pre-op
alpha, beta-adrenergic blockage for 2 wks
=> control HTN, volume expansion
alpha-blockade
- no specific alpha blocker
BP < style="font-weight: bold;">propanolol
Gerota's fascia separate from kidney
Open vs. lap adrenalectomy
lap for tumor <>
Dyspepsia (from the Greek "δυς-" (Dys-), meaning hard or difficult, and "πέψη" (Pepsi), meaning digestion) refers to disorders of the stomach involving symptoms such as heartburn, nausea, pain, or general discomfort.
Many cases of dyspepsia are caused by stomach ulcers which are diagnosed with a barium meal test or gastroscopy. Most cases of ulcer dyspepsia are caused by Helicobacter pylori infection. However, some studies also suggest non-ulcer dyspepsia may be resolved from eradicating this infection. In some situations (such as in ulcers), high levels of gastric acid may irritate the stomach lining and cause dyspeptic symptoms. Dyspepsia may also be a side effect from drugs treating other diseases.
--------------------------------------------------------------------------Catecholamines are chemical compounds derived from the amino acid tyrosine. Some of them are biogenic amines. Catecholamines are water soluble and are 50% bound to plasma proteins, so they circulate in the bloodstream. The most abundant catecholamines are epinephrine (adrenaline), norepinephrine (noradrenaline) and dopamine. They are produced mainly from the adrenal medulla and the postganglionic fibers of the sympathetic nervous system. Epinephrine acts as a neurotransmitter in the central nervous system and as a hormone in the blood circulation. Norepinephrine is primarily a neurotransmitter of the peripheral sympathetic nervous system but is also present in the blood (mostly through "spillover" from the synapses of the sympathetic system).
High catecholamine levels in blood are associated with stress, which can be induced from psychological reactions or environmental stressors such as elevated sound levels or intense light. Extremely high levels of catecholamine (also known as catecholamine toxicity) can occur in CNS trauma due to stimulation and/or damage of nuclei in the brainstem, particularly those nuclei affecting the sympathetic nervous system. In emergency medicine, this occurrence is widely known as catecholamine dump.
Catecholamines cause general physiological changes that prepare the body for physical activity (fight-or-flight response). Some typical effects are increases in heart rate, blood pressure, and blood glucose levels. Some drugs, like tolcapone (a central COMT-inhibitor), raise the levels of all the catecholamines.
Catecholamines have the distinct structure of a benzene ring with two hydroxyl groups, an intermediate ethyl chain and a terminal amine group. They have a half-life of approximately a few minutes when circulating in the blood.
Monoamine oxidase (MAO) is the main enzyme responsible for degradation of catecholamines.
--------------------------------------------------------------------------A pheochromocytoma (also phaeochromocytoma, UK spelling) is a neuroendocrine tumor of the medulla of the adrenal glands originating in the chromaffin cells, which secretes excessive amounts of catecholamines, usually adrenaline and noradrenaline. Extra-adrenal paragangliomas (often described as extra-adrenal pheochromocytomas) are closely related, though less common, tumors that originate in the ganglia of the sympathetic nervous system and are named based upon the primary anatomical site of origin. Bilateral disease is present in approximately 10% of patients.
Features
The signs and symptoms of a pheochromocytoma are those of sympathetic nervous system hyperactivity:
- Elevated heart rate
- Elevated blood pressure; a clue to the presence of phechromocytoma is orthostatic hypotension, a fall in systolic blood pressure greater than 10 mmHg on making the patient stand
- Palpitations
- Anxiety often resembling that of a panic attack
- Diaphoresis
- Headaches
A pheochromocytoma can also cause resistant arterial hypertension. A pheochromocytoma can be fatal if it causes malignant hypertension, or severely high blood pressure.
Diagnosis
The diagnosis can be established by measuring catecholamines and metanephrines in plasma or through a 24-hour urine collection. Care should be taken to rule out other causes of adrenergic (adrenalin-like) excess like hypoglycemia, stress, exercise, and drugs affecting the catecholamines like methyldopa, dopamine agonists, or ganglion blocking antihypertensives. Various foodstuffs (e.g. vanilla ice cream) can also affect the levels of urinary metanephrine and VMA (vanillyl mandelic acid). Imaging by computed tomography or a T2 weighted MRI of the head, neck, and chest, and abdomen can help localize the tumor. Tumors can also be located using Iodine-131 meta-iodobenzylguanidine (I131 MIBG) imaging. One diagnostic test used in the past for a pheochromocytoma is to administer clonidine (Catapres®), a centrally-acting alpha-2 agonist used to treat high blood pressure. Clonidine mimics catecholamines in the brain, causing it to reduce the activity of the sympathetic nerves controlling the adrenal medulla. A healthy adrenal medulla will respond to clonidine by reducing catecholamine production; the lack of a response is evidence of pheochromocytoma. Another test is for the clinician to press gently on the adrenal gland. A pheochromocytoma will often release a burst of catecholamines, with the associated signs and symptoms quickly following. This method is NOT recommended
Pheochromocytomas occur most often during young-adult to mid-adult life. Less than 10% of pheochromocytomas are malignant (cancerous).
These tumors can form a pattern with other endocrine gland cancers which is labeled multiple endocrine neoplasia (MEN). Pheochromocytoma may occur in patients with MEN 2 and MEN 3. VHL (Von Hippel Lindau) patients may also develop these tumors.
Treatment
Surgical resection of the tumor is the treatment of first choice. Given the complexity of perioperative management, and the potential for catastrophic intra and postoperative complications, such surgery should be performed only at centers experienced in the area. In addition to the surgical expertise that such centers can provide, they will also have the necessary endocrine and anesthesia resources as well.
--------------------------------------------------------------------------In medicine, an incidentaloma is a tumor (-oma) found by coincidence (incidental) without clinical symptoms and suspicion. It is a common problem: up to 7% of all patients over 60 may harbor a benign growth, often of the adrenal gland, which is detected when diagnostic imaging is used for the analysis of unrelated symptoms. With the increase of "whole-body CT scanning" as part of health screening programs, the chance of finding incidentalomas is expected to increase.
When faced with an unexpected finding on diagnostic imaging, the clinician faces the challenge to prove that the lesion is indeed harmless. Often, some other tests are required to determine the exact nature of an incidentaloma.
--------------------------------------------------------------------------Von Recklinghausen disease(Neurofibromatosis)
Neurofibromatosis is an autosomal dominant genetic disorder. It encompasses a set of distinct genetic disorders that cause tumors to grow along types of nerves and, in addition, can affect the development of non-nervous tissues such as bones and skin. The tumors can grow anywhere on or in the body.
Types
There are two major forms and one newly discovered form:
- Neurofibromatosis type I (was known as Von Recklinghausen disease after Friedrich Daniel von Recklinghausen). Incidence is 1:3000.
- Neurofibromatosis type II (or "MISME Syndrome"). Incidence is 1:40,000.
- Schwannomatosis is a rare form that is clinically and genetically distinct from types I and II. Multiple Schwannomas (rather than Neurofibromas) occur, and about one-third of patients have these tumors in only one part of the body. Incidence is 1:40,000. The vestibular nerve is spared. Pain is the primary symptom, although numbness, tingling and weakness can also occur. Schwannomas are always benign.
- Six other, extremely rare, forms are also recognized:
Diaphoresis is excessive sweating commonly associated with shock and other medical emergency conditions.
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A palpitation is an awareness of the beating of the heart, whether it is too slow, too fast, irregular, or at its normal frequency; brought on by overexertion, adrenaline, alcohol, disease (such as hyperthyroidism) or drugs, or as a symptom of panic disorder. More colloquially, it can also refer to a shaking motion.
Nearly everyone experiences a very occasional awareness of their own heart beating but, when it occurs frequently, it can indicate a problem. Palpitations may be felt with heart problems, but also in anemias and thyroid malfunction.
Attacks can last for a few seconds or hours, and may occur very infrequently, or more than daily. Palpitations alongside other symptoms, including sweating, faintness, chest pain or dizziness, indicate irregular or poor heart function and should be looked into.
Palpitations may also be associated with anxiety and panic attacks, in which case psychological assessment is recommende--------------------------------------------------------------------------
MIBG (iodine-131-meta-iodobenzylguanidine) scintiscan
MIBG is a nuclear scan test that uses injected radioactive material (radioisotope) and a special scanner to locate or confirm the presence of pheochromocytoma and neuroblastoma, which are tumors of specific types of nervous tissue.
How the test is performed Return to top
A radioisotope (MIBG, iodine-131-meta-iodobenzylguanidine) is injected into a vein. Later that day (or the next day) you lie on a table that is positioned under the arm of the scanner. The abdomen is scanned. You may be asked to return for repeated scans for 1 - 3 days. Each scan takes 1 - 2 hours.
After injection of the radioisotope, you are given Lugol's iodine solution to block uptake into the thyroid. Because the radiation from this radioisotope is fairly high compared to most other radioisotopes, some precautions may be necessary for a few days after the test. The nuclear medicine personnel will instruct about specific precautions, which may include flushing the toilet twice after each use (to dilute radioactive material excreted in the urine) or other precautions.
What abnormal results mean Return to top
Most often, this test is used to locate pheochromocytoma. It may be very useful to detect multiple tumors or tumors that are located outside the adrenal tissues.
Additional conditions under which the test may be performed include multiple endocrine neoplasia (MEN) II
Metanephrine is a metabolite of epinephrine created by action of catechol O-methyltransferase on epinephrine. It is also known as 4-hydroxy-3-methoxy-alpha-((methylamino)methyl) Benzenemethanol with formula C10-H15-N-O3.
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Propranolol (INN) (IPA: [proˈprænəloʊl]) is a non-selective beta blocker mainly used in the treatment of hypertension. It was the first successful beta blocker developed. Propranolol is commonly marketed by Wyeth under the trade name Inderal.
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Gerota's fascia
