Once a patient is diagnosed with pheochromocytoma, the patient needs to start medical treatment until she/he is ready for surgical resection. The preoperative medical preparation is often not optimal in clinical practice. Preoperative preparation, however, is critical for an uneventful operation and postoperative recovery.
First of all, pheochromocytoma is not an indication for urgent operation. There is time to prepare the patient for surgical resection of the tumor. For the uninitiated doctors and patients, the diagnosis of pheochromocytoma could elicit a sense of excitement and urgency. They would intuitively imagine that it makes sense to remove the tumor as soon as possible. While pheochromocytoma should be removed as soon as possible, the patient has to be prepared meticulously for the surgery.
The technical part of surgical resection of a pheochromocytoma is not complicated by itself. The tricky part is the patient's "hemodynamic status" during and after operation. "Hemodynamic status" means the patient's hear rate, blood pressure, and quality of the microcirculation inside organs. Pheochromocytoma differs from most other tumors because it produces catecholamines which increase blood pressure and heart rate to dangerous levels. Anesthesia and manipulation of the tumor often release large bouts of catecholamines that dramatically change the patient's "hemodynamic status". Preoperative preparation help prevent these complications and that's why it should be given to all patients.
The preoperative preparation needs to achieve 3 goals: 1) normalization of blood pressure, 2) replenishment of the patient's body fluid, and 3) recovery of heart function. All 3 goals are critically important and all should be met before the operation. Clinically inapparent abnormal heart functions are rather common in patients with pheochromocytoma and these should be reversed as much as possible before the operation.
There are 3 components in the preoperative preparation: 1) blood pressure medications, 2) salty food or intravenous infusion of fluids, and 3) a sufficient duration of the preparation for at least 2 weeks.
Depending on the patient's individual conditions, the doctors may make some adjustment on the regimen of preoperative preparation.
In my own experience, pheochromocytoma resection nowadays is remarkably safe if the patient is carefully prepared before the operation. The same operation can become disastrous if the patient is not carefully prepared. And most importantly, there is no reason why a patient is not carefully prepared. No excuse. Period.
Dr. Pheo
Tuesday, March 31, 2009
Monday, March 30, 2009
The final diagnosis of pheochromocytoma
The final diagnosis of pheochromocytoma is based on three critical pieces of evidence: 1) elevated biochemical markers for pheochromocytoma, 2) an adrenal tumor, and 3) agreement between the extent of marker elevation and the imaging characteristics of the tumor. I have discussed 1) and 2) in previous posts, I will focus on 3) in this one.
What I mean for "agreement" is that the tumor size and the levels of markers should be roughly matching because larger tumors tend to have higher marker levels. For example, if a patient has plasma normetanephrine levels 20 fold elevated and has a 2-cm left adrenal tumor, the small adrenal tumor is not the pheochromocytoma that produces such high levels of plasma normetanephrine. There should be another tumor somewhere in the body. Another example. If a patient has plasma normetanephrine levels 1.5 fold elevated but has a left adrenal tumor measuring 5.5 cm, this left adrenal tumor is probably not a pheochromocytoma. I cannot give a very quantitative rule about marker levels and tumor size because there are no such rules. A doctor's experience is key here. The good news is that most tumors do have agreement between marker levels and tumor size on the first imaging study.
Dr. Pheo
What I mean for "agreement" is that the tumor size and the levels of markers should be roughly matching because larger tumors tend to have higher marker levels. For example, if a patient has plasma normetanephrine levels 20 fold elevated and has a 2-cm left adrenal tumor, the small adrenal tumor is not the pheochromocytoma that produces such high levels of plasma normetanephrine. There should be another tumor somewhere in the body. Another example. If a patient has plasma normetanephrine levels 1.5 fold elevated but has a left adrenal tumor measuring 5.5 cm, this left adrenal tumor is probably not a pheochromocytoma. I cannot give a very quantitative rule about marker levels and tumor size because there are no such rules. A doctor's experience is key here. The good news is that most tumors do have agreement between marker levels and tumor size on the first imaging study.
Dr. Pheo
The first follower of this blog
Today I noticed that this blog has its first follower. I thank you, my friend, to follow this blog. I promise all of you that you will find this blog providing much-needed information on pheochromocytoma diagnosis and treatment. I want to take this opportunity to remind you of asking me questions about pheochromocytoma or commenting on the contents of my blog.
I believe that my blog has a unique niche among all websites on pheochromocytoma. The most important feature of this blog is that it is interactive. It will be just like a doctor friend who has in-depth knowledge in pheochromocytoma. Either you are not sure whether you have pheochromocytoma, or you do have it but are not sure what the best treatment is, or you want to know how you should be followed after tumor resection, you can ask Dr. Pheo. In the future, after many questions are asked and answered, you probably will find your questions already answered by reading past articles. As pheochromocytoma and neuroendocrine tumors are so intriguing, I am sure that I will always have something to write about, and you will always have something to ask about.
Dr. Pheo
I believe that my blog has a unique niche among all websites on pheochromocytoma. The most important feature of this blog is that it is interactive. It will be just like a doctor friend who has in-depth knowledge in pheochromocytoma. Either you are not sure whether you have pheochromocytoma, or you do have it but are not sure what the best treatment is, or you want to know how you should be followed after tumor resection, you can ask Dr. Pheo. In the future, after many questions are asked and answered, you probably will find your questions already answered by reading past articles. As pheochromocytoma and neuroendocrine tumors are so intriguing, I am sure that I will always have something to write about, and you will always have something to ask about.
Dr. Pheo
Sunday, March 29, 2009
Imaging studies for diagnosing pheochromocytoma
If a doctor feels that the biochemical tests show a reasonable chance for pheochromocytoma, the doctor will order abdominal CT or MRI to see if there is an adrenal tumor. Abdominal ultrasound is not good enough for characterizing an adrenal tumor. On CT, most pheochromocytomas appear as a high-density mass, and on MRI, several protocols will determine if an adrenal mass is more likely to be a benign adenoma or "atypical" or "consistent with" pheochromocytoma.
A contrast material will be given intravenously. The contrast material is given because it will tell if a given organ or tumor has a lot fo blood supply or not. Pheochromocytoma has many blood vessels in it, thus it shows "enhancement" (just means it appears much brighter after contrast material is given.)
Sometimes, the biochemical tests suggest pheochromocytoma but CT or MRI does not find any adrenal masses. Now two things are possible: either the patient has pheochromocytoma but the tumor is somewhere else, or the patient does not actually have pheochromocytoma. The doctor should pause and weigh the evidence and decide which way to go.
If the biochemical tests strongly suggest that a patient has pheochromocytoma, regardless of imaging results, a functional scan called "MIBG" is done afterwards. Pheochromocytoma is very savvy in taking up MIBG. The value of MIBG scan is questionable for most patients but is considered an extra layer of caution. The MIBG scan can be falsely positive for some patients.
A contrast material will be given intravenously. The contrast material is given because it will tell if a given organ or tumor has a lot fo blood supply or not. Pheochromocytoma has many blood vessels in it, thus it shows "enhancement" (just means it appears much brighter after contrast material is given.)
Sometimes, the biochemical tests suggest pheochromocytoma but CT or MRI does not find any adrenal masses. Now two things are possible: either the patient has pheochromocytoma but the tumor is somewhere else, or the patient does not actually have pheochromocytoma. The doctor should pause and weigh the evidence and decide which way to go.
If the biochemical tests strongly suggest that a patient has pheochromocytoma, regardless of imaging results, a functional scan called "MIBG" is done afterwards. Pheochromocytoma is very savvy in taking up MIBG. The value of MIBG scan is questionable for most patients but is considered an extra layer of caution. The MIBG scan can be falsely positive for some patients.
Thursday, March 26, 2009
How is pheochromocytoma diagnosed?
Once pheochromocytoma is suspected in a given patient, biochemical tests need to be done first. A common mistake is doing an abdominal imaging test before biochemical tests are done. Imaging tests should only be done after biochemical tests highly suggest pheochromocytoma.
There are actually a few issues with biochemical tests that can make the test selection and test result interpretation rather complicated. There are 5 biochemical tests for pheochromocytoma: 2 measure chemicals in the blood, 3 measure chemicals in the urine. The 2 blood tests are called "plasma catecholamines" and "plasma fractionated metanephrines". The 3 urine tests are called "24-hour urine catecholamines", "24-hour urine metanephrines", and "24-hour Vanillylmandelic acid (VMA)". Another blood test called "chromogranin A (CGA)" may be occasionally used but this test is secondary to the other 5 tests.
So which test or tests to use? There are no clear or definitive answers to this question. A doctor has to take several issues into consideration. Usually only specialists like Dr. Pheo myself knows most of the nuts and bolts of all those tests but even specialists sometimes do not know what the best test is. In an ideal situation, "plasma fractionated metenephrines" are the test Dr. Pheo prefers for a variety of reasons. For a certain patient in certain situation, any one of the 5 tests can be the best test.
Now the results are back. What do they mean? Test results should not be simply labeled as "normal" or "abnormal". The extent of elevation of the results compared with normal reference range is very important. Test results are also open to interference by medications, diseases, and human errors. So if you have a test result that is only 20% above the normal range, don't panic. Chances are you don't have pheochromocytoma. On the other hand, a 20% increase may indicate pheochromocytoma in other people. Really tricky, isn't it? Although Dr. Pheo myself is very comfortable in interpreting test results for most patients, Dr. Pheo at times has to ponder on some results for days before making a call.
There are actually a few issues with biochemical tests that can make the test selection and test result interpretation rather complicated. There are 5 biochemical tests for pheochromocytoma: 2 measure chemicals in the blood, 3 measure chemicals in the urine. The 2 blood tests are called "plasma catecholamines" and "plasma fractionated metanephrines". The 3 urine tests are called "24-hour urine catecholamines", "24-hour urine metanephrines", and "24-hour Vanillylmandelic acid (VMA)". Another blood test called "chromogranin A (CGA)" may be occasionally used but this test is secondary to the other 5 tests.
So which test or tests to use? There are no clear or definitive answers to this question. A doctor has to take several issues into consideration. Usually only specialists like Dr. Pheo myself knows most of the nuts and bolts of all those tests but even specialists sometimes do not know what the best test is. In an ideal situation, "plasma fractionated metenephrines" are the test Dr. Pheo prefers for a variety of reasons. For a certain patient in certain situation, any one of the 5 tests can be the best test.
Now the results are back. What do they mean? Test results should not be simply labeled as "normal" or "abnormal". The extent of elevation of the results compared with normal reference range is very important. Test results are also open to interference by medications, diseases, and human errors. So if you have a test result that is only 20% above the normal range, don't panic. Chances are you don't have pheochromocytoma. On the other hand, a 20% increase may indicate pheochromocytoma in other people. Really tricky, isn't it? Although Dr. Pheo myself is very comfortable in interpreting test results for most patients, Dr. Pheo at times has to ponder on some results for days before making a call.
Tuesday, March 24, 2009
How pheochromocytoma is suspected?
In the present times and for the majority of patients, pheochromocytoma becomes a concern in 3 situations: symptoms, adrenal tumor, and familial syndromes.
The symptoms of pheochromocytoma are very diverse thus pheochromocytoma has earned the name as a "master mimicker" of other diseases. The symptoms can be as simple as mild hypertension but can also be as dramatic as strokes. The unique symptoms of pheochromocytoma "spells" are not as common nowadays as described in the classic literature. The spells may be elicited by emotional stress, exertion, pressure to the abdomen, or other stimuli the patients themselves often can figure out and avoid. The spells start with a sudden sense of doom or extreme fear, accompanied with headache, heart pounding, sweating, eye sensitivity to light, and other symptoms. A spell can last a few minutes to much longer. Blood pressure is invariably increased initially during a spell but blood pressure may drop to hypotension range due to reflexes of the body. Unusual hypertension and one or more components of the spell may make the doctor suspect pheochromocytoma. Only 0.2%-2% people with these symptoms actually have pheochromocytoma while symptoms are caused by other diseases in the majority of patients.
A mass in the adrenal glands is another reason for the doctor to suspect pheochromocytoma. Up to 5% of adrenal masses are pheochromocytoma. Therefore, tests for pheochromocytoma should be performed whenever a patient is found to have an adrenal mass. Pheochromocytoma found this way can be "silent" and the patient may be even free of symptoms.
The third situation is monitoring people who are carriers for mutations that cause familial tumor syndromes. Multiple endocrine neoplasia type II (MENII), von Hippel-Lindau disease (VHL), neurofibromatosis type 1 (NF1), and familial paraganglioma syndrome are the most common syndromes. Carriers of the mutations related to these syndromes need to be screened periodically by blood tests and imaging.
Of course a combination of any of the 3 situations can occur.
The symptoms of pheochromocytoma are very diverse thus pheochromocytoma has earned the name as a "master mimicker" of other diseases. The symptoms can be as simple as mild hypertension but can also be as dramatic as strokes. The unique symptoms of pheochromocytoma "spells" are not as common nowadays as described in the classic literature. The spells may be elicited by emotional stress, exertion, pressure to the abdomen, or other stimuli the patients themselves often can figure out and avoid. The spells start with a sudden sense of doom or extreme fear, accompanied with headache, heart pounding, sweating, eye sensitivity to light, and other symptoms. A spell can last a few minutes to much longer. Blood pressure is invariably increased initially during a spell but blood pressure may drop to hypotension range due to reflexes of the body. Unusual hypertension and one or more components of the spell may make the doctor suspect pheochromocytoma. Only 0.2%-2% people with these symptoms actually have pheochromocytoma while symptoms are caused by other diseases in the majority of patients.
A mass in the adrenal glands is another reason for the doctor to suspect pheochromocytoma. Up to 5% of adrenal masses are pheochromocytoma. Therefore, tests for pheochromocytoma should be performed whenever a patient is found to have an adrenal mass. Pheochromocytoma found this way can be "silent" and the patient may be even free of symptoms.
The third situation is monitoring people who are carriers for mutations that cause familial tumor syndromes. Multiple endocrine neoplasia type II (MENII), von Hippel-Lindau disease (VHL), neurofibromatosis type 1 (NF1), and familial paraganglioma syndrome are the most common syndromes. Carriers of the mutations related to these syndromes need to be screened periodically by blood tests and imaging.
Of course a combination of any of the 3 situations can occur.
Friday, March 20, 2009
What is pheochromocytoma?
Pheochromocytoma is a tumor from the inner part of the adrenal gland. Each person has two adrenal glands, one on each side of the body. The adrenal gland is located on top of the kidney (thus the name ad-renal). The adrenal gland has an outer layer and an inner core. The outer layer is called cortex while the inner core called medulla. Pheochromocytoma is a tumor from the adrenal medulla. There are other cells in the body that are very similar to the cells in adrenal medulla and they can also produce pheochromocytoma as well. In that case, the pheochromocytoma is called paraganglioma.
Pheochromocytoma makes substances called catecholamines. These substances constrict blood vessels, increase blood pressure, deplete the body of fluids, and hurt the heart. Catecholamines are also normally produced by the adrenal medulla. Only in excess amounts, catecholamines cause harm to the body.
Pheochromocytoma is indeed very rare. Because a common symptom of pheochromocytoma is hypertension, pheochromocytoma is often considered in patients with unusual hypertension. Another reason that pheochromocytoma is often an issue is adrenal mass identified through the wide use of abdominal imaging.
Pheochromocytoma is a tricky disease. It can be deadly if not diagnosed or treated properly. On the other hand, if diagnosed and treated properly, patients with pheochromocytoma can be completely cured. Although the most common presentation of pheochromocytoma is hypertension, pheochromocytoma can mimics many other diseases such as anxiety, palpitation, or heart attack. In a recent study, it is shown that more than 20% of patients who undergo surgical removal of a presumable pheochromocytoma end up not having pheochromocytoma. Similarly more than 20% of patients who indeed have pheochromocytoma are diagnosed as a dangerous surprise.
I welcome patients and colleagues to post comments or questions to this blog and we can go over all aspects of pheochromocytoma on a case-by-case basis. Please keep any personal information confidential. For example, even if you yourselves may have hypertension and a concern for pheochromocytoma, just say "a friend of mine (or my cousin Johnny), 45-year-old man, has hypertension for a year and his doctor tells him that he may have pheochromocytoma."
Pheochromocytoma makes substances called catecholamines. These substances constrict blood vessels, increase blood pressure, deplete the body of fluids, and hurt the heart. Catecholamines are also normally produced by the adrenal medulla. Only in excess amounts, catecholamines cause harm to the body.
Pheochromocytoma is indeed very rare. Because a common symptom of pheochromocytoma is hypertension, pheochromocytoma is often considered in patients with unusual hypertension. Another reason that pheochromocytoma is often an issue is adrenal mass identified through the wide use of abdominal imaging.
Pheochromocytoma is a tricky disease. It can be deadly if not diagnosed or treated properly. On the other hand, if diagnosed and treated properly, patients with pheochromocytoma can be completely cured. Although the most common presentation of pheochromocytoma is hypertension, pheochromocytoma can mimics many other diseases such as anxiety, palpitation, or heart attack. In a recent study, it is shown that more than 20% of patients who undergo surgical removal of a presumable pheochromocytoma end up not having pheochromocytoma. Similarly more than 20% of patients who indeed have pheochromocytoma are diagnosed as a dangerous surprise.
I welcome patients and colleagues to post comments or questions to this blog and we can go over all aspects of pheochromocytoma on a case-by-case basis. Please keep any personal information confidential. For example, even if you yourselves may have hypertension and a concern for pheochromocytoma, just say "a friend of mine (or my cousin Johnny), 45-year-old man, has hypertension for a year and his doctor tells him that he may have pheochromocytoma."
Thursday, March 19, 2009
Introduction by Dr. Pheo
Hi,
I am a medical specialist in pheochromocytoma and other neuroendocrine tumors. These tumors are rare and a general doctor may not have enough experience in them. Diagnosis and treatment of these tumors are therefore often sub-optimal. I would like to share my experience with patients and colleagues through this blog and hope all of us will benefit.
I will initially keep my identity anonymous. Please keep in mind that I do NOT establish a physician-patient relationship between me and another person through communicating with this blog. I can NOT offer specific medical opinions on this blog. I am happy to provide general information regarding your question. You are solely responsible for the consequences of using the information I provide here. If you have a question, please keep your personal information confidential and use general precautions as you would in any communications over the internet.
I can not promise that I will check the blog frequently. For questions you consider urgent, please direct them to your own physicians.
Best regards,
Dr. Pheo
I am a medical specialist in pheochromocytoma and other neuroendocrine tumors. These tumors are rare and a general doctor may not have enough experience in them. Diagnosis and treatment of these tumors are therefore often sub-optimal. I would like to share my experience with patients and colleagues through this blog and hope all of us will benefit.
I will initially keep my identity anonymous. Please keep in mind that I do NOT establish a physician-patient relationship between me and another person through communicating with this blog. I can NOT offer specific medical opinions on this blog. I am happy to provide general information regarding your question. You are solely responsible for the consequences of using the information I provide here. If you have a question, please keep your personal information confidential and use general precautions as you would in any communications over the internet.
I can not promise that I will check the blog frequently. For questions you consider urgent, please direct them to your own physicians.
Best regards,
Dr. Pheo
Subscribe to:
Posts (Atom)