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]