Insulinomas - tumors of the pancreas
Insulinomas
- tumors of the pancreas
Insulinoma
also see dog cancer
also see dog lumps
Insulinomas
- tumors of the pancreas
Question: DR. RICHARDS, I have a six year old shep/husky that we
believe has a tumor
on his pancreas, his last blood work showed his insulin level @ 1400
and
his sugar level @31.His sugar level is so low he is extremely weak. I
can
not find anyone who has any information on the chances of removing
the
tumor,and the risks involved. It is very diffucult to make a decision
about
exploratory surgery with very little information .I understand that
you
can't diagnois via internet, but would appreciate greatly any input
you
could give me. I really need to gather facts as soon as possible. THANK
YOU
Answer: Joseph-
Insulinomas, the tumor of the pancreas that leads to low blood sugar
and
high insulin production, will commonly metastasize (some people say
this
tumor always metastasizes) and recurrences of the tumor after removal
do
occur in most patients. It is a good idea to have chest X-rays taken
prior
to making a surgical decision, since it would be much less likely to
help
if there are already visible tumors in the chest. If there is a good
ultrasonagrapher in your area, an ultrasound exam can help to determine
the
size of an insulinoma prior to surgery and help to determine if there
is a
metastasis to the liver.
Surgery increases the lifespan of affected dogs because it helps to
reduce
the amount of excessive insulin being produced by the tumors. This
effect
is usually temporary because the tumor has usually spread. It isn't
possible to find all the tumors once this has happened and eventually
there
will be a recurrence of the hypoglycemia. As an average, according
to
information on the Veterinary Information Network, the interval before
return of clinical signs is about 8 months if there are already visible
metastases prior to surgery and about 14 months if there are no metastases
visible at the time of surgery. With a combination of medical and surgical
therapy, life spans of about 2 years have been recorded for patients
after
diagnosis of insulinoma.
It is risky to do surgery on patients who have low blood sugar. It is
probably best to have an experienced surgeon for this procedure. We
have
removed insulinomas in our practice and the surgery itself is not all
that
difficult but fluids with dextrose should be administered during surgery
and blood glucose monitored during surgery, as well. I am still more
comfortable referring these patients to a facility with twenty-four
hour
care and board certified surgeons when possible.
After surgery, when hypoglycemia returns as a problem, medical therapy
works for a while to control clinical signs. Medical therapy includes
feeding many small meals, administration of prednisone and use of
diazoxide. There may be some addition information available to your
vet by
calling a veterinary school, as there has been a small amount of work
done
on specific chemotherapy agents for this condition and the use calcium
channel blockers (usually used to control blood pressure) as an aid
in
controlling blood sugar since they sometimes lower it as a side effect
to
their normal actions.
It is possible to use medical therapy without doing surgery but surgical
removal of as much of the mass as possible helps more than anything
else in
extending lifespan of patients with insulinomas. This is a temporary
effect, so you have to think about how important it is to you and your
dog
to gain a year or so of time. There are a few dogs who actually
seem to
recover completely post surgically but the percentage is probably less
than
5% and may be even lower than that.
Hope this helps some.
Mike Richards, DVM
6/5/2000
Insulinoma
Q: DEAR DR. MIKE; MY DOG , SUKI , GOLDEN RETRIEVER
LAB MIX , EIGHT YEARS OLD: - STARTED HAVING SEIZURES BACK IN NOVEMBER.
- AFTER MANY TESTS MY VET DIAGNOSED HER WITH INSULINOMA. - SHE HAD AN OPERATION
AND THEY REMOVED TUMORS FROM HER PANCREAS, LYMPH NODE, LIVER. - They had
to leave a tumor that was too dangerous to remove near an artery. - She
is on hormonal injection 2x's / day AM & PM = "Sandostatin." - The
vet has us feeding her 4 small meals per day which has seemed to help the
seizure problem (only problem she still loves to steal food! -that's good!)
- She injured her shoulder (a few month's after the operation - she started
feeling better and wanted to run & play).
The VET prescribed prednisone @ 1/2 tab (whole tab = 20mg.) 1x every
other day and this seems to have helped the limping from the shoulder injury.
- She seems to have suffered some nerve damage on the right side of her
face (she had been on the prednisone for c. 2 mos. at this point): drooping
= right ear, right side of mouth = constant drooling, right eye not able
to blink & I think there is some loss of sight in that right eye. -
HISTORY OF IMPORTANCE: was always very active & got plenty of exercise
but has now slowed down some, she had LYME DISEASE c. 8 yrs. ago, has arthritis
in her back.
QUESTIONS -?? DO YOU THINK THAT THE PREDNISONE CAUSED OR CONTRIBUTED
TO THIS NERVE DAMAGE ??. ?? DO YOU KNOW OF ANY OTHER MEDICINE, HERBS, VITAMINS,
ETC. AS AN EFFECTIVE ALTERNATIVE TO PREDNISONE ??THANK YOU M.
Answer: I don't think that the prednisone is a likely suspect
as a cause of the facial paralysis. This happens spontaneously in some
golden retrievers and it is also associated with hypothyroidism and brain
tumors. Since your dog has a metastatic cancer, pressure on the facial
nerve from a tumor has to be considered.
Octreotide (Sandostatin Rx) is a relatively new treatment for insulinoma
and the initial reports on it were promising. A journal article by Simpson
et. al in the Journal of Small Animal Practice suggests that it is not
an effective treatment, though. I have no personal experience to draw from
and can not help with deciding who is right (the vets who think it works
or the ones who think it doesn't).
An alternative medication is diazoxide (Proglycem Rx). It is expensive
and sometimes hard to find but it has been the standard treatment for the
hypoglycemia associated with insulinomas for some time. It is almost always
used in conjuction with prednisone so it is unlikely you could discontinue
the pred with its use.
There is an alternative veterinary medicine question and answer board
on AOL (keyword pets, then use the veterinary hospital button) if you wish
to seek alternative treatment advice.
Mike Richards, DVM
Last edited 01/30/05
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