Posted by Allie Vance | 13 September 2009, 7:30 pm
The body’ s electrolytes (sodium and potassium) levels are maintained by the kidneys and also by two small glands that sit right on top of each kidney. These glands are called adrenal glands. An uncommon tumor, called pheochromocytoma (present in 0.2% of people who have high blood
pressure), may sometimes be present in one of the adrenal glands. This can throw a diagnostic puzzle at the physician. You may end up getting treated for a variety of disorders, such as panic attacks, hypertension, heart arrhythmia, migraine headaches and more. This little devil has can mimic almost anything. In my clinical practice I have come across one such case.
Step 1
The mechanism behind the signs and symptoms of pheochromocytoma is the secretion of various chemical and hormonal substances released by the tumor cells such as serotonin, epinephrine, norepinephrine and dopamine. Most of these hormones are excitatory and are normally secreted by the body especially on the occasions of excitement, causing an increase in the heart rate, blood pressure, breathing and sweating.
Step 2
The “Classic triad”:
The three classical symptoms of pheochromacytoma that should prompt your doctor to evaluate you for pheochromocytoma are: episodic headache, sweating and tachycardia.
Step 3
Sustained or paroxysmal hypertension is the most common sign of pheochromocytoma. A young person with very high blood pressure should definitely be considered for evaluation of pheochromocytoma. Five to 15 percent of patients, however, have normal blood pressure.
Step 4
Other symptoms may include palpitations, shortness of breath, generalized weakness and panic attack-type symptoms.
Step 5
Labs:
The following labs should be ordered if Pheochromocytoma is suspected:
* A 24-hour urine catecholamine and metanephrines
* Fractionated plasma free metanephrines
* Plasma catecholamine
* Clonidine suppression test (A drug called Clonidine is administered orally, and plasma catecholamine or fractionated metanephrines are measured before and three hours after the dose)
Radiologic tests:
* CT and MRI may be used to locate the tumor in the adrenal glands
* If CT and MRI fail to locate the tumor and if the biochemical tests are positive then 123-I-metaiodobenzylguanidine (MIBG) scintigraphy may be done
Other imaging:
* Octreoscan
* Total body MRI
* PET scanning (Positron Emission Topography)
Warnings About 10 percent of all catecholamine-secreting tumors are malignant. Malignant pheochromocytomas are histologically and biochemically the same as benign ones. The only difference is that malignant pheochromocytoma is locally invasive and throws distant metastases, which may occur as long as 20 years after resection. Therefore a careful follow-up is warranted
- By shahbasharat | AC
0 comments:
Post a Comment