The pancreas, when it comes to the pancreas in pathology, you divide it into exocrine
and endocrine pathology.
Here, our topic is endocrine pancreatic pathology, our discussion first will walk us through
enteroendocrine tumors and by that we mean, those tumors that we find in our pancreas
that will then affect different parts of your enteric system.
Let’s begin.
First, we will take a look at MEN type 1, multiple endocrine neoplasia type 1.
Its gene that you must know is MENIN.
Hence, if you want, multiple endocrine neoplasia type 1 N, autosomal dominant, the tumor suppressor
gene has been lost.
The 3 Ps from MEN type 1 include the following.
You want to go in alphabetical order, if it makes it easier for you, Pan Para Pit, I will
tell you what each one of those mean.
The Para will be hyperparathyroidism resulting in increased calcium or hypercalcemia, the
Pan will be pancreatic Islet cell tumor and we will be walking through this in great detail.
You probably heard of or have heard of a gastrinoma known as Zollinger-Ellison syndrome in which
your patient is now suffering from recurrent refractory peptic ulcers and Insulinoma.
Glucagonoma, Somatostatinoma, a VIPoma, all of these are part of your pancreatic Islet
cell tumors.
Whenever you think about pancreatic Islet cell, most students tend to stop at gastrinoma
MZE, please do not do that anymore.
Quickly, if it is Insulinoma, you should be thinking about your glucose levels being very,
very low, too much insulin.
We will be walking through that in great detail.
That will be one of the common ones.
Glucagonoma, the 3 Ds, we have Diabetes because of excess glucose, too much glucagon, Diarrhea,
Dermatologic and this is then referred to as being necrolytic migratory erythema in
which it may look like Impetigo where you have honey crusted lesions on the sides of
the mouth.
The Somatostatinoma, here you would have diabetes, diarrhea and gall stones and with VIPoma,
we will be using an acronym known as WDHA, water diarrhea hypokalemia and achlorhydria.
The Pit is pituitary adenoma, the most common pituitary adenoma or functioning type in which
the hormone that is being released will in fact be prolactin.
So, it will be a prolactinoma that we will be looking at.
Under MEN 1: Pan, pancreatic Islet cell tumor; Para, hyperparathyroidism and hypercalcemia;
Pit, pituitary, you should be thinking about your pituitary adenoma.
Thymic carcinoid, rare.
What are we looking at here?
Well, our topic first will take us into a beta Islet cell tumor, so therefore, this
is an Insulinoma.
With Insulinoma, first and foremost, please make sure that you know that it is a beta
Islet cell tumor, is one of the most common pancreatic Islet cell tumor, could be part
of your MEN type 1.
With all this insulin that is being produced, how?
Endogenously or exogenously?
Obviously, endogenously.
The reason I bring that to your attention is because something that you want to be familiar
with biochemically is the fact that if you are producing insulin endogenously, in vivo,
in excess, along with insulin, you are also releasing what into circulation technically?
Good, C-peptides.
So, you would expect to find high C peptide levels in a patient with Insulinoma.
Isn’t that interesting?
Whereas if it was exogenous use of insulin, maybe you have an athlete in which he or she
is trying to promote anabolism or increased muscle mass, then you would not find such
high levels of C-peptides.
Can be benign or malignant; majority of these are benign, keep that in mind.
All other pancreatic Islet cell tumors tend to be malignant.
So, that is a big deal.
With all of this insulin that is coming out endogenously as a C-peptide, focus upon that,
and you have the Whipple triad.
Now, instead of memorizing Whipple triad, use common sense so that you can figure out
as to what is going on with your patient.
First and foremost, with all this insulin, you can expect there to be hypoglycemia and
blood glucose levels, which to keep it simple, should be approximately 100, huh, drops all
the way down to 50 mg/dL.
Measured at the time of symptom in which your patient here with a severe hypoglycemia may
result in stupor, dizziness because of hypoglycemia and the way that you relive this obviously
is going to by giving this patient glucose.
Now, this is relieving the hypoglycemia obviously not treatment; a treatment is going in there
and resecting the particular tumor.
Keep in mind that whenever you do have an Insulinoma or you are presented as such, in
your mind are you thinking, “Hmm, what other endocrine organs might be affected?
Could it be hyperparathyroidism?
Could you find hypercalcemia in your patient?
Could it be prolactinoma with galactorrhea and maybe loss of libido?”
All part of MEN 1.
Let’s continue with the pancreatic Islet cell tumor.
Insulinoma management maybe difficult localisation after biochemical workup, the imaging studies,
CT, MRI, octreotide, endoscopic ultrasound with or without biopsy so you can actually
find it.
First line of treatment is surgical resection, must take it out, in terms of final cure.
Remember though, with Whipple triad things that you want to do in the meantime to make
sure that you are managing your patient is that when there is severe hypoglycemia that
you are giving your patient in fact glucose.
Do not forget that.
Then the medical treatment may be needed to control hypoglycemia, that is of utmost importance.
Diazoxide, Octreotide, Verapamil, phenytoin, things that you want to keep in mind when
you are dealing with a patient with Insulinoma where perhaps surgically was not able to properly
manage or cure your patient.