On this table, we’ll take a look at differentials
of your hyperthyroidism.
Pretty much repetitive of the algorithm that
we saw earlier, however, this time in a table
However you wish to learn, make sure that
you know these important differentials.
We’ll divide this into the following columns
and I’ll walk you through this: causes,
mechanism, thyroid exam and the radioactive
iodine and initially, it will be hyperthyroidism
with a normal or high radioactive iodine uptake.
First, autoimmune thyroid diseases will be
our-our organization or our first category.
Hashitoxicosis, what does that mean?
Remember, with Hashimoto, I think we’re
clear now that initially there is every possibility
with that lymphocytic infiltration of the
thyroid gland in which your colloid is being
destroyed in releasing T3,T4 presenting how?
Initially, with hyperthyroidism.
That’s my topic for this entire table.
This is then called Hashitoxicosis, how appropriate?
Initially, you are going to have those autoimmune
or antibodies that are then attacking maybe
the thyroid globulin or maybe it is then attacking
the peroxidase, those are the most common
It could really have destruction anywhere.
Thyroid exam, you’re going to feel a goiter
and here, initially, you’re going to find
increased radioactive iodine uptake.
In Graves’ disease, this is your TSI that
we talked about plenty of a diffused goiter
and here it will be a diffused radioactive
If you take a look at a scintigram here, take
a look at the thyroid gland and you see these
two lobes that are “lit up” quote and
quote that’s because the entire thyroid
gland diffusely is taking up radioactive iodine
uptake or radioactive iodine.
The second organization will be autonomous
Uptake may be a low, if recent iodine load
led to iodine induced hyperthyroidism.
Let’s take a look.
We have toxic multinodular goiter, toxic adenoma…
who is your patient?
Remember that picture that I showed you where
you had a diffused enlargement of the neck?
The thyroid gland was huge with lots of cysts
and with such enlargement of the thyroid gland,
there is every possibility that you may then
rupture blood vessels and therefore cause
haemorrhage into the cysts.
Activating gene mutations, nodules is what
you’re going to find.
Thyroid exam usually greater than two and
a half centimetres.
Here, the type of uptake, not diffused but
Each nodule behaves like increased activity.
Choriocarcinoma a trophoblastic disease and
we have hyperemesis gravidarum.
Here, you find hCG which behaves like TSH,
minimal goiter, but you’re going to find
an increase in radioactive iodine.
Then we have pituitary tumour with increased
TSH, minimal goiter, increased radioactive
iodine… welcome to secondary hyperthyroidism.
Next, we’ll take a look at hyperthyroidism
with near absent radioactive iodine uptake,
what does this take us into in terms of category?
Differentials will be thyroiditis including
painful, painless, postpartum, radiation thyroiditis.
The thyroid glands are being destroyed the
patient is now presenting how?
Destruction releases of your stored hormones;
tender and sub-acute, what does sub-acute
mean to you?
Viral, non-tender in silent.
Here, the thyroid gland is being destroyed,
you cannot expect your thyroid gland to take
up the radioactive iodine.
Iodine induced here iodine surplus called
Jod-Basedow, with iodine surplus here the
thyroid gland says, “I’m producing enough
T3, T4… why would I want to produce more?”
Nodular diffused goiter, decreased radioactive
Struma ovarii, we talked about, we have metastatic
follicular thyroid cancer, that’s a big
This is ectopic thyroid tissue and we have
normal thyroid exam.
Here, once again, radioactive iodine is decreased
over the thyroid… over the thyroid.
What do you mean?
Huh, what if you find an ovary that behaves
like a thyroid gland?
That’s Struma ovarii, a derivative of teratoma.
There it would be taking up iodine, do you
understand the significance when it says radioactive
iodine uptake over the thyroid?
There it will be depressed.
But, if it’s located ectopically either
metastatic and follicular, especially enough
to metastasize; the follicular type of thyroid
cancel off the metastasize.
That is not the most common though; what is
common is papillary.
And we have exogenous and factitious.
You’re taking up T3 and T4, you’re going
to knock out or you’re going to create negative
feedback with decreased TSH, decreased receptor
activity, radioactive iodine is depressed.
Ladies and gentlemen, once you fully have
understood the foundation of hyperthyroidism
initially and prior to this, the physiology,
you go through the algorithm and you go through
tables, there is absolutely no way that you
could possibly miss any question.
You have yourself a proper educated guess.