Call for Papers
- Seventh Biennial Medical Symposium on VHL
October 26-28, 2006, London, Ontario, Canada
Dr. William Manger of New York University and the National
Hypertension Association, giving the keynote address. Photo
by Debra Harlander
The First International Symposium on Pheochromocytoma was held in Bethesda,
Maryland, October 20-23, 2005. It is hard to believe that in 2005, this
is the first international symposium ever held on this topic. [See
Note 1] Drs. Graeme Eisenhofer and Karel Pacak of the U.S. National
Institutes of Health co-chaired the meeting, bringing together 180 participants
from all over the world. Forty patients and family members came from as
far away as Texas, Michigan, and Oregon to be part of the experience.
Dr. William Manger of New York University opened the conference with
this sobering thought: “Tragically up to 50% of pheochromocytomas
are still discovered at autopsy, mainly because the diagnosis of this
neuroendocrine tumor was not considered.” Families that know they
may be at risk of a pheo should know the symptoms of a pheo so that they
can help lead their doctors to this diagnosis.
“Pheochromocytoma
is still the most treacherous, deceptive tumor on the planet,” said
Dr. Manger. “Missing the diagnosis almost invariably results in devastating
cardiovascular complications or death. Clinicians must always think of pheochromocytoma
whenever evaluating a patient with sustained or episodic hypertension or
any manifestations suggesting elevated catecholamines. Very rarely, familial
pheochromocytoma may cause no hypertension, symptoms or signs. But biochemical
testing can always establish the presence or absence of a pheochromocytoma,
and localization with MRI, CT, or 131 or 123 I-MIBG is almost always possible.”[2]
“The very large variety of symptoms and signs encountered in patients
with pheochromocytoma frequently suggests a number of other conditions
and may mislead and confuse the physician and cause an erroneous diagnosis.
This treacherous tumor has correctly earned the title of the “Great
Masquerader.” Above all, it is essential when confronted with any
manifestation of these conditions that the clinician be forever alert
and think of pheochromocytoma!” It is also important for a family
with VHL to suggest to their physicians that a pheo should be considered,
and be prepared to give literature to their doctors to convey the best
possible information – better than they remember from medical school.
Alison’s story in the following article
is a good demonstration of how a mother saved her children by pressing
for the best answers and the best treatment.
In order to raise the rate of diagnosis, the conference focused on:
Understanding the many ways pheos may present, to raise consciousness
of these symptoms
Agreeing on diagnostic criteria, especially agreeing on the tests
needed to diagnose a pheo
Agreeing on which biochemical tests are the most specific for pheo,
and the most sensitive in finding even smaller tumors
Agreeing on which imaging studies are the most effective in finding
extra-adrenal pheos
Agreeing on when patients should be screened for one or more of the
genetic alterations that can result in a pheo.
Familial pheochromocytomas may occur in people with any one of six known
genetic syndromes:
Von Hippel-Lindau (VHL)
Multiple Endocrine Neoplasia (MEN, especially type 1)
Neurofibromatosis Type 1 (NF1)
A newly recognized panel of genes referred to as SDHB, SDHC, and
SDHD which cause head and neck paragangliomas
And at least 70% of pheos occur at random in the general population.
Pheochromocytomas (called “pheos” for short) were first described
by Frankel in 1886. Dr. Von Euler won the 1946 Nobel prize for proving
that norepinephrine (NE) was a neurotransmitter. But diagnosing and localizing
or finding pheo within the body has been extremely difficult until recent
advances in imaging and chemical diagnosis.
Pheos arise from chromaffin tissue in the sympathetic
nervous system. 85% of pheos occur in the adrenal glands, but 15%
occur outside the adrenals. These “extra-adrenal” pheos
are called paragangliomas. For simplicity, the term “pheo”
is here used to include these neuroendocrine tumors, wherever they
occur in the body.
The genetic factors involved in pheochromocytoma/ paraganglioma
(Pheo/PGL) syndromes represent a perfect example for these exciting
advances in modern biomedicine (4-7). Until recently, more than
90% of these rare but clinically important catecholamine-producing
tumors were thought to occur as sporadic nonhereditary entities
that should not need any genetic screening unless there was a family
history of a certain form of multiple endocrine neoplasia.
The last three years have seen mounting evidence that a substantial
proportion of patients with these tumors have a definable genetic
defect with potentially important clinical implications.
Debra Harlander,
Pheochromocytoma Support
They are usually described as exhibiting a classic triad of symptoms:
headache, palpitations, and sweating. But not everyone exhibits all three
symptoms. Dr. Debbie Cohen of the University of Pennsylvania and others
shared statistics for their patients that showed that approximately 60%
of patients complain of headaches, about 50% have palpitations or panic
attacks, and about 35% have sweating. Some have all three, but more often
people exhibit one or two of these symptoms. And some have none of these
three symptoms at all. Nearly 50% have normal blood pressure.
Pheos in pregnancy are often misdiagnosed as pre-eclampsia. Failure to
recognize a pheo in pregnancy carries a high mortality rate for both the
mother and the fetus. As long as the doctor knows about the pheo, especially
early in the pregnancy, precautions can be taken to protect the mother
and the child.
In studies of “incidental” findings of pheos (found while
looking for something else), the pheos found in this way are generally
large -- 5-11 cm (2-4.5 inches in diameter). Such a large tumor has likely
been growing for a number of years, and has probably been causing symptoms
for some years.
Dr. Marta Barontini from Argentina shared her study spanning her 40-year
career in pediatric medicine. She finds that pheos in children have more
severe and more sustained symptoms than in adults. It is especially important
to do genetic studies in children with pheos, as a higher percentage of
them have a genetic syndrome. She has stayed in touch with all her patients,
and has recalled them for genetic screening as additional genetic information
has become available.
Dr. Henri Timmers of the Netherlands did a review of 141 papers in the
medical literature on pheos in pregnancy, reporting a total of 174 cases.
Only 7% of these had previously been treated for pheo, and only 17% of
them had any history of high blood pressure. The initial diagnosis was
wrong in 31% of these cases. The risks to the mother were highest in cases
of incorrect diagnosis. The outcome for both mother and child were largely
dependent upon timely recognition of the problem, and appropriate treatment.
Things tended to go best when the pheo was removed earlier than 24 weeks
of pregnancy, or if the pregnancy was carefully managed to term and the
pheo was removed after delivery. It is critically important to inform
the obstetrician if the patient might be at risk of a pheo so that the
mother and child can be diagnosed early and treated carefully.
How is it that six different genes can all cause a pheo? Dr. William
Kaelin presented the work he published in Cancer Cell. Mutations in VHL,
RET, NF1, SDHB, SDHC, and SDHD can give rise to pheochromocytoma/paraganglioma.
These different genetic lesions may all act by decreasing the activity
of a 2-oxoglutarate-dependent oxygenase, SM-20/EglN3/PHD3, resulting in
reduced apoptosis of neural crest cells during development.”
[3]
There are a number of checks and balances in the
cell that verify that cells are proceeding properly. If they are
badly formed, the body’s normal protective mechanisms kill
off the badly formed cell and make a new one. This is a process
called apoptosis. In the case of pheos, cells that would normally
have been killed off go on to become tumors. These genes interfere
with the normal process of apoptosis and allow the cell to become
a pheo or paraganglioma.
The most important messages for people with familial syndromes
that may cause pheos is to keep strong, to monitor for early detection,
and do what you have to do to get appropriate treatment. Read, learn,
and help to bring your doctors up to speed on pheos.
Remember that you can’t protect yourself if you don’t
know you are at risk. Make it your business to find out whether
you may be at risk, and take responsibility for your own health
and that of your children.
Dr. Hartmut Neumann of Germany planing the violin
at dinner, a tradition at VHL meetings. Photo by
Debra Harlander.
Since knowledge about pheochromocytoma/paraganglioma syndromes is so
scarce among the vast majority of physicians and health practitioners,
the conference participants asked that recommendations and updated treatment
guidelines should be posted on the PRESSOR website (www.pressor.org) along
with a list of centers with a satisfactory level of experience in treating
pheochromocytoma. This information will be developed over the coming year.
The formal Proceedings of this conference will be published in the Annals
of the New York Academy of Sciences, forecasted for October 2006.
Notes: Our thanks to Prof Stefan R.
Bornstein, University of Dresden, Germany, Debra Harlander, and Jo Ann
Monroe of the Pheochromocytoma Support Board for their assistance in the
preparation of this report.
1. An earlier meeting
broke ground for this effort atCold Spring Harbor NY in November 2003.
For the results of that conference, see Endocrine-Related Cancer (2004)
11: 423-436.
2. Finding a pheo or paraganglioma
is best done with CT or MRI, or an MIBG. An MIBG test is a nuclear medicine
procedure using a radioactive isotope or tracer, which is absorbed by
pheochromocytoma tissue. Meta-Iodo-Benzyl-Guanidine (MIBG) is injected
into the patient before the scan is performed, making the pheo stand out
clearly on the diagnostic pictures. There are two radioisotopes used for
this purpose, 131-MIBG or 123-MIBG. 123-MIBG is far superior, but has
a shorter half-life and must be used within hours of being made up. Nonetheless
it is becoming more available because of its greater ability to seek out
pheos and paragangliomas wherever they are hiding in the body.
3. S. Lee, W. Kaelin, et al., Neuronal
apoptosis linked to EglN3 prolyl hydroxylase and familial pheochromocytoma
genes: developmental culling and cancer. Cancer Cell. 2005 Aug;8(2):155-67.
The quote is from the commentary in the same issue by Dr. Patrick Maxwell,
A common pathway for genetic events leading to pheochromocytoma. Cancer
Cell. 2005 Aug;8(2):91-3.
As printed in the VHL Family Forum 13:4, December
2005. For permission to reprint, please contact VHL Family Alliance, editor@vhl.org. Further information is available from the VHL Family Alliance, info@vhl.org.