From:
Bruce Williams, DVM
Date: 2001-08-19 21:44:00 UTC
Subject: Re: adrenal and insulinoma malignancies ??
--- In Ferret-Health-list@y..., ferret mom <ferrets_985@y...> wrote:
> I'm a bit confused on the fact that sometimes I see
> all adrenal tumors referred to as malignancies or
> cancers. I guess that's where I'm confused. Are all
> malignancies cancer and all cancers malignancies?
> Does one of these terrible words have a double meaning
> of just being a tumor and not what I usually think of
> when I hear the words? I think of them as
> interchangeable. I know the tumor that was in the
> gland removed from my girl was not actually cancer. It
> was described as a neoplasm. Are all insulinomas
> cancer that will spread out of the pancreas and effect
> other organs? Or are they non cancerous in some or
> all of the cases? My girl also had an insulinoma
> removed. She had no symptoms and the insulinoma was
> found during the adrenal surgery. So far she has a
> normal sugar that is holding at around 120 when she
> has been tested.
The thread on this is pretty good, and both Sukie and Stephanie have
very valid points. The terminology of neoplasms can be confusing,
and I'm sure even vets can be confused from time to time.
The proper term for what you are talking about is neoplasm (or
literally "new growth). For one reason or another, a clone of cells
begins to grow uninhibited by normal substances or mechanisms. The
word "tumor" may be technically correct, but it is actually non-
specific - tumor is Latin for a swelling, but it could also be an
abscess, or anything else that causes swelling - so I try to stay
away from it.
Now this neoplasm may be benign - without the ability for cells to
detach into the bloodstream or lymph, move to another tissue, and set
up shop - or malignant (where they can do this.) The process of
microscopic piece of a tumor moving to another organ is called
metastasis.
Metastasis is the hallmark of malignancy. The worst tumors have the
propensity to go anywhere and start growing (like lymphoma).
However, we can recognize malignant tumors even before they
metastasize, often by characteristic features seen under the
microscope.
Adrenal carcinomas (malignant adrenal tumors) are interesting
neoplasms. Although they possess the ability to metastasize, only a
small number do, and usually only late in the course of disease. It
is likely that they do metastasize a lot, but have trouble gaining a
foothold in distant tissues, so it takes a long time and many
attempts if they ever truly metastasize.
Insulinomas are generally not malignant tumors as they only very
rarely metastasize. The presence of multiple tumors in the same
organ over time is not metastasis. We do not understand the
mechanism behind the generation of these tumors, and when we do
surgery to remove them, we really are only treating the end point of
this process, without address the cause. Thus it is really no
surprise that the rate of recurrence is about 40% within 10 months.
With kindest regards,
Bruce Williams, DVM