Dear Dr. Roach: Could you please explain what makes a pheochromocytoma cancerous, what the symptoms are, what the protocol for treatment is and where the best places for treatment might be, as very little is known about this kind of cancer?
P.L.
A pheochromocytoma (fee-oh-kroh-moh-sigh-TOH-muh) is a rare tumour that usually secretes epinephrine and norepinephrine, substances that increase blood pressure. More than 90 per cent of people with this tumour will have high blood pressure, and typical symptoms include headache, sweating and heart racing. Not everyone has all of these symptoms. They can occur at any age but are most common in the 40-50 age group. Only about one person in 500 with hypertension will have a pheochromocytoma. These tumours usually arise in the adrenal gland, but can occur in other locations, where they may be called paragangliomas.
Even though 90 per cent of pheochromocytomas are not malignant, it does not mean it is a benign condition. The degree of blood pressure elevation can itself be life-threatening, and may be a problem during surgery, especially if the condition is unknown at the time. In the even rarer situation of a malignant (cancerous) pheochromocytoma, the situation is substantially harder to cure because of the cancers themselves as well as the hormones they secrete. Even a benign-appearing pheochromocytoma, which has been successfully removed surgically, can recur up to 20 years later with evidence of cancerous spread, so all need to be carefully monitored.
All people with pheochromocytomas need to be treated by experts. A solitary pheochromocytoma is removed surgically. Medication to block the effects of the epinephrine and norepinephrine must be given before surgery, and an experienced anesthesiologist is critical.
For cancerous pheochromocytomas, I would recommend treatment at a specialty cancer hospital. This is yet another situation where a greater degree of personal and institutional experience translates to better cure rates. Malignant pheochromocytomas are treated with some combination of surgery, chemotherapy and radiation.
There are cases of these kinds of tumours that run in families. People who present with multiple tumours or have a family history may undergo genetic screening.
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Dear Dr. Roach: I鈥檓 a 44-year-old male. I had aortic valve repair surgery in 2008. I also had a cardiac ablation for ventricular tachycardia in 2009. I had a normal heart catheterization in 2011. However, in 2013, I had a cardiac CT, which showed 鈥渕ild stenosis of the distal left circumflex artery,鈥� but the 鈥渓eft anterior descending and the right circumflex arteries were normal. There was myocardial bridging of the mid-ramus branch without appreciable stenosis.鈥�
I was told that this is nothing to worry about. There was nothing mentioned about bridging on my catheterization two years earlier. Should I be concerned about this, and should I have the catheterization repeated?
D.G.B.
You have had quite a few issues with your heart. Normally, the left main artery splits into the left anterior descending (LAD) and the circumflex artery, but in some people, there is a third branch, called the ramus. You have a ramus artery.
You also have myocardial bridging, which happens to only some people. In most cases, the arteries of the heart sit right on top of the heart muscle. In about two per cent of people, the heart muscle goes over a part of the blood vessel. This is called myocardial bridging, and it is present from birth. The CT scans of the heart have such high resolution that they are very good at spotting this variation.
A small amount of bridging does not seem to cause any increased risk of heart disease. However, long segments may increase risk of heart attack. The segment that is within the muscle can be completely closed when the heart squeezes, which stops blood flow and may predispose a person to clots.
The report mentions some stenosis (narrowing) of the circumflex artery. If your cardiologist thinks it is significant, I would guess that you would be on appropriate medication, including a statin, aspirin and beta blocker. These would reduce any possible risk from the myocardial bridging, even though most people with bridging don鈥檛 need specific treatment.
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Dr. Roach regrets that he is unable to answer individual letters, but will incorporate them in the column whenever possible. Readers may email questions to [email protected] or write him at P.O. Box 536475, Orlando, FL 32853-6475.
