To Debbie Riccio:
 
>He showed it to me under the scope and I learned something yesterday:  (Bruce,
>if I get this wrong PLEASE correct me) In my mind I always visualized islet
>cells as being separate from the pancreas and sort of "sitting" on top of
>the pancreas in a little group.  Well, they are dispersed throughout the
>pancreas and more or less IN the pancreas as a part of the pancreas - normally
>anyway.  When one of these things starts growing out of control, that's
>when it becomes a tumor.  Mandy's tumor looked like one big giant normal
>islet cell - just significantly larger.
 
        No, you seem to have it straight - the islets are scattered throughout
the rest of the pancreas - which is responsible for making the digestive
enzymes used in breaking doen food in the small intestine.
 
>Now I understand what everyone is talking about when they say that outcome
>depends on whether it is one big tumor or whether there are many teeny
>tiny tumors all over the place.
 
>My other confusion is the term "cancer."  Dr. Baggs said this tumor is
>benign.  Yet I also thought of insulinoma as "cancer" and cancer is bad.
>Dr Baggs said the term "cancer" is often used incorrectly.  Cancer is a
>tumor that can be either benign or malignant - malignant is bad cancer.
 
        Cancer is a poor term for neoplasia - which is an uncolntrolled groth
of cells.  Classically cancer - meaning "crab" in Latin - is used for
malignancy - due to the fact that malignant tumors invade adjacent tissue s-
much like a crab gripping a rock with its claws and legs.  While all
insulinomas should be considered POTENTIALLY malignant, with the ability to
spread to other tissues, most behave in a benign fashion, and surgical excision
is curative.
 
 
> But how can you tell by looking at a slide if it has metastasized or not?
 
        You can't.  You have to see it in other tissues - mesentery and liver
being the most common.  In dogs and cats - these tumors have a high rate of
metastasis, but in ferrets, they don't.  Also, if you take out an islet cell
tumor, but the blood glucose doesn't come back up - you have two options - a)
you didn't get all of it, or b) there was metastasis.
 
--
Bruce Williams, DVM, DACVP              Department of Veterinary Pathology
[log in to unmask]               Armed Forces Institute of Pathology
[log in to unmask]             Washington, D.C.  20306-6000
(202) 782-2600/2602
[Posted in FML issue 1161]