Parathyroid
glands have the most un-predictable anatomy in the human body. Parathyroid
glands are typically found on the back side of the thyroid gland (para
means "around", so parathyroid glands are "around the
thyroid glands"). In fact,
about 80% of parathyroid glands are found right behind the thyroid gland
as shown in the picture at the top-right of this page which is showing the BACK SIDE of the thyroid gland,
demonstrating that the four
parathyroid glands are closely associated with the back of the thyroid. It
really isn't this simple. Because of how parathyroid glands are formed (when we are in our
mother's womb), they can be anywhere in the neck from just below the
jaw--all the way down into the chest next to the heart. The
picture on the left shows the location of the pink thyroid gland in a patient's
neck. The black dots outline the possible locations that the left parathyroid
glands can be found. You can see that 20% of parathyroid glands are not found next to the thyroid, thus these little guys can be very hard to
find! Remember, normal parathyroid glands are only the size of a grain of rice
(half of a pea), and get to be about the size of an almond when they develop a
tumor (called a parathyroid adenoma) and make too much parathyroid
hormone. Knowing this variable anatomy will also help you understand why the
experience
of the surgeon is so important to a good outcome following parathyroid
surgery. Remember, 30% of patients with hyperparathyroidism will have two
or more bad glands, and 20% of parathyroid glands are not next to the
thyroid, therefore about 40% of people will have at least one parathyroid
tumor that is NOT located right behind the thyroid. Since the scans are
not good at finding these small guys, you must rely on the experience of
the surgeon. If you are reading this page, then somebody will tell you
"you must find the most experienced parathyroid surgeon you
can".
One more time for emphasis: There are no scans that can
accurately find half of the parathyroid tumors that patients have. The
average parathyroid tumor is only the size of an almond, and the scan
simply can't find them. Take a look at the pictures
of parathyroid tumors and see that about half of them did not show up
on a scan! The key to successful parathyroid surgery is not the scan, it's
the experience of the surgeon. The key to winning a major golf tournament
is not the clubs, it is the guy swinging the clubs.
Tip of the day: Don't keep having
tests and more tests, instead find an expert and let him/her take care of
it. Don't let your endocrinologist or family doctor keep ordering the
scans that are on this page! As much a positive role these doctors play, they really should not be ordering any
localizing test. (note, if you come to our center, we will not look at any
scans you obtain somewhere else, it will be a waste of time). Let the expert parathyroid surgeon do
the scans. As you will
read below, most sestamibi scans are done very poorly, therefore, most of
you reading this page will get a negative scan and everybody will get
confused and all of a sudden things become difficult. Don't get confused, and do
not put too
much emphasis on these scans. Every single day we get emails from patients
who tell us that they have hyperparathyroidism and their doctor sent them
for a sestamibi scan and the scan is negative---then everybody goes into a
"tizzy" because they don't understand this page. STOP getting all these tests! Find
an expert parathyroid surgeon and let them find the tumor.
Many experts feel that no study or test is required to "identify" the diseased parathyroid gland (or glands) prior to an operation for hyperparathyroidism. They feel that surgeons with enough experience can find the problem gland and remove it to cure the disease in
about 95% of all cases...without any pre-op tests. Of course what they
don't tell you is that this often requires the patient to be under general
anesthesia for two to five hours so the surgeon can make a large incision
and do an extensive exploration of your neck. What they also don't tell you
is that there are only a few surgeons in the US that fall into the
"expert" category who can demonstrate a 95% cure rate
(most general surgeons have a cure rate between 85 and 90%). The days of
making a big incision and exploring the entire neck on all patients with parathyroid
disease are gone. The concept is correct, however, and wherever you
read about parathyroid disease they will tell you... you want an expert
surgeon.
Now
that we have told you to stop getting scans we will tell you that every
patient should have a sestamibi scan. HOWEVER, the reason to get the
scan is not necessarily to find the parathyroid tumor, the scan also
shows thyroid nodules, it shows thyroid goiters, it shows "cold"
thyroid nodules, it shows the location of the thyroid in the neck, and it
shows if there are parathyroid tumors in the chest. We prefer negative
scans on our patients. Let me say this again, we prefer that our patients
have negative scans, as these are often the easiest operations to perform
because the parathyroid tumor is stuck to the back side of the thyroid
gland and thus very easy to find! The surgeons at the Norman Parathyroid
Center have invented and developed many aspects of modern sestamibi
scanning, and we have learned that the NEGATIVE information is much more
important than the Positive information. We get scans to show where the tumor is NOT located,
rather than showing where it IS located. This change has allowed us to
perform a mini operation on 100% of people. Yep, you read that right. We
want lots of negative information. A positive scan does not save us 10
seconds in the operating room because we need to find all four parathyroid
glands in order to get above 99% cure rates for our patients. Finding the
big tumor is easy, its finding the 3 small normal glands that is
hard. Please watch our surgery
video to understand this more.
Summary of Different Parathyroid Scans
Sestamibi
scanning is the best way to find a parathyroid tumor. But as you know,
it will only show about half of the parathyroid tumors and is frequently
wrong when positive. There are several
other tests used that can occasionally discover which parathyroid gland
enlarged. Some tests (ultrasound, CAT scan, and MRI scan)
simply use pictures of one form or another to find a BIG gland. These
studies
just look at parathyroid SIZE. Of course, there are other small things in
your neck (like lymph glands and thyroid nodules) which can give false tests. Thus, CAT Scans, and MRI Scans should NOT be
used to find a bad parathyroid gland. Let us repeat this: If your doctor
orders an MRI scan on you to find a parathyroid tumor then get up and walk
out. MRI and (and CAT scans to a lesser degree) show less than 5% of ALL parathyroid glands. Therefore, if you have a
CAT scan or MRI scan, you have a 95% chance of having a test that costs
money, takes time, and won't help a thing (except confuse people).
Ultrasound exams done at your local radiology center
or the radiology department of a hospital will also not show the tumor in
most cases. Less
than 12% of these ultrasound scans will show the tumor... not because the tumor isn't
there... but because this test is HIGHLY dependant upon the skill of the
person doing the test. If they don't do this every day, the scan will not
be useful (like taking a photograph
of your kids at night without a flash--you can't see the kids, but the are
still there). Ultrasound scans done by endocrinologist or your endocrine
surgeon in their office can be helpful and this is a reasonable thing
for you to have. If the endocrinologist is not doing it, you probably don't want it. We
would NEVER send a patient for an ultrasound test to be done at the local
radiology place. However, we do it ourselves on every patient as soon
as they get into the operating room, right before we operate. Note, we are
evaluating their THYROID also at this time to make sure they don't have a
thyroid problem that we can fix at the same time.
When
people have a scan to find their bad parathyroid gland and it doesn't show
anything, they get confused and their doctor gets confuesed. If the right techniques are not used during
your x-ray, it's like taking a picture of the planet Saturn with your
cell-phone camera. You take the picture but the photo doesn't show the big
planet with the rings. It's not because the planet has disappeared,
it's because you used the wrong camera, the wrong film, and the wrong lens
to photograph the planet. This occurs hundreds of times per day when
patients are sent to their local radiology department for some x-ray to
help find the bad parathyroid gland. Unfortunately, at least 75% of you reading
this will have already undergone some silly test that didn't help. You
will know what we are saying is true, but your inexperienced doctor will
order test after test...after test. Stop the silliness.
FNA
Needle Biopsy of Parathyroid Tumors. A
dangerous trend has emerged in the past few years that you must know
about and avoid. Some endocrinologists and/or surgeons will want to prove
that what they believe is a parathyroid tumor on a scan is really a
parathyroid tumor, so they will biopsy this gland with a needle. This is
called a FNA or "fine needle aspiration" biopsy, or "needle
biopsy" of the parathyroid gland. This is dangerous and should
almost never be done. Read
a report of this in our blog! This will cause death to some of the parathyroid
tumor, and when it heals with scar tissue (like all tissues heal), the
scar tissue can involve the voice box nerve. This will cause tremendous
troubles for the surgeon and increases dramatically the chance that you
will never talk again. Furthermore, the scarring that occurs will look
like cancer under the microscope resulting in the pathologist determining
that your parathyroid tumor was a cancer... even when it was not. We will not accept
patients into our clinic for surgery if they have had a parathyroid biopsy
using an 18 or 20 gauge needle. If you have had a biopsy of your
parathyroid gland with a smaller needle, then we will accept you into our
practice but will require you to sign a written statement acknowledging
that the needle biopsy greatly increases the difficulty of the operation
with increased risks for complications, and increased difficulty for the
pathologist. To read our recent publication on this topic in one of
the major Endocrinology journals, click here: Diagnostic
Aspiration of Parathyroid Adenomas Causes Severe Fibrosis Complicating
Surgery and Final Histologic Diagnosis. Thyroid.
2007 Sep 22
The following list describes briefly the different tests which may help a surgeon or endocrinologist find the diseased parathyroid gland which is over secreting parathyroid hormone.
The Sestamibi Scan is now the preferred method for identifying a diseased parathyroid gland prior to an operation.
Almost
80 percent correct when it shows a single
gland when done by experts that do LOTS of these scans. But 40-50%
will be negative regardless of who does it. Therefore, you must understand
that this is just a scan and nothing more. Far too much emphasis is put on
this scan and the results of this scan. There are technique differences which make these scans at some hospitals
much better than they are at other hospitals. Bottom
line, it's just a scan. It is way over used. It is emphasized way too
much. We wish nobody ever got these scans because they usually confuse
people and cause lengthy delays in treatment. If you have a parathyroid
problem, you need an expert surgeon not a scan.
See our
video of The
Importance of the Sestamibi Scan.
See our
video on How
to Interpret Your Sestamibi Scan.
SPECT scanning is a
mechanism by which a three dimensional picture can be obtained following injection of
the Sestamibi drug. SPECT scanning DECREASES the reliability and accuracy
of sestamibi scans, but is done because the radiologist gets paid more
to do this. You should refuse this scan. We review over 4,000 sestamibi scans per year,
and about 40% of them include SPECT scanning. It is almost never
helpful and should not be done. We NEVER use SPECT scanning
unless the tumor is in the chest next to the heart. In our opinion, this
is the only time SPECT scanning should be used. We cannot stress enough
that if you get a SPECT scan, your scan will be LESS valuable and you have
at least a 60% chance of the scan being negative, and at least a 70%
chance of them "seeing" something on your scan that isn't really
there. If you get a SPECT scan somewhere else and then decide to
come to our center for your operation, we will not look at your SPECT
scan. It provides zero information that will be useful to us.
MRI scans
are almost never useful because MRI scans don't show parathyroid tumors well.
At best, an MRI will find less than 8% of parathyroid tumors, therefore, the indications for getting this scan are VERY few.
We operate on at least on person per week that had an unsuccessful
operation somewhere else because the surgeon thought he knew where the
parathyroid tumor was--and he saw it on an MRI scan. If your doctor orders
an MRI scan to find your parathyroid tumor, stand up, laugh at them, and
walk out! IT IS INAPPROPRIATE TO GET AN MRI SCAN ON ANY PATIENT
TO TRY TO FIND A PARATHYROID TUMOR. Insurance
companies should not pay for it. I hope we made this clear.
CT scans
are used much less frequently since the introduction of the Sestamibi scans. They can occasionally be helpful, but getting a CT scan prior to a first operation for hyperparathyroidism is
NEVER warranted. THIS TEST SHOULD NOT BE DONE! It does not
show parathyroid tumors. Sometimes a patient will have a failed
operation and so the doctors start ordering lots of x-rays, including CAT
scans. Of course, if you had an
experienced surgeon, you are very unlikely to have a failed operation.
Thus, get an expert surgeon and don't worry about wasting your time on
these dumb tests.
Ultrasound is
less costly than CAT scans and MRIs, they are easily performed, carries no significant risks, and can be useful in localizing a parathyroid
adenoma. We use ultrasound on all our patients when they are taken to the
operating room just before their operation. Only about 12-15 percent of ultrasound scans are
correct if they
are performed at the local radiology center--therefore, don't waste your time
on this scan unless it is performed by your endocrinologist or your
surgeon in his/her
office. Ultrasound is very accurate when used to examine the
thyroid but not for parathyroids--unless done by your doctor!
If your
doctor just orders this test to be done by some technician at the local
hospital or radiology center, then you are wasting your time and money. This is one of the reasons the cost of medicine is going out of
control...doctors ordering too many tests even when the tests have little
chance of helping.
SESTAMIBI SCANS RESULTS...
WHAT TO DO ABOUT YOUR NEGATIVE SESTAMIBI SCAN.
We get to review about 4,500 sestamibi scans per year. These come to us
from many hospitals across the US. Sestamibi scans are extremely
variable depending on the techniques used. These are NOT regular x-rays
which every hospital can perform. Sestamibi scans require the highest
degree of technician input. The use of special filters, patient placement,
etc, are very important. Therefore, MOST scans done in the US are not very
good. About 30% of the scans in the US are WORTHLESS, another 30% are
terrible or poor quality.
Sestamibi scanning is often not done correctly, and done for the
wrong reasons, and interpreted wrong. Be careful of your sestamibi scan.
It can be extremely helpful if your sestamibi scan is positive, but if
your scan is negative it doesn't mean much. It does NOT mean you don't
have parathyroid disease if your scan is negative (we will say this 10
times so you understand it).
If you have a scan that is "negative" it does NOT mean
that you don't have parathyroid disease. It's not negative because you don't have a parathyroid
tumor, usually its negative because they do not know how to do this test and
a test done poorly won't show the tumor. Or, the parathyroid tumor is
simply behind the thyroid gland and so it doesn't show up. Worse yet, your doctor may become confused and tell
you to do nothing about your disease--all because some technicians don't
know what they are doing! NOTHING ON THIS WEB SITE IS MORE IMPORTANT
THAN THIS SIMPLE PARAGRAPH! DO NOT MAKE THIS MISTAKE!
If there was one thing that you should take away from this page it is
this... sestamibi scans are very nice tools to help the surgeon know what
they are going to find when they open you up. They will know the size of
your thyroid, the presence of any thyroid nodules, if your parathyroid
tumor is in your chest... but an expert parathyroid surgeon does not care
if the scan is positive or negative!
The results of the scan should never be used to determine who
goes to surgery and who does not. Using the scan to make this decision is
not correct. Almost 75% of the patients we operate on and remove a
parathyroid tumor came to see us with a negative sestamibi scan
done somewhere else prior to coming to see us. We do the exact same
operation on all people, regardless of scan results. Negative scan
patients get the exact same operation that takes exactly the same amount
of time (17.5 minutes on average), and has the same expected cure rate
(over 99%).
This page was last updated 05/18/2013
