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Dr. Shupack,

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let's take a look at this 17-year-old young

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lady that has primary amenorrhea.

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And I'll withhold the rest of the historical information.

0:11

I have in front of you a coronal T2, two spin echo, a T1,

0:15

one with contrast showing a beautiful central pituitary

0:19

tuft or portal plexus blush right in the midline.

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It's gorgeous. And then on the right side,

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on the viewer's right,

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we have a sagittal contrast-enhanced MRI.

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The region of the proximal stalk medial eminence

0:32

the stalk and then down into the gland,

0:34

which looks maybe a little bit juicy.

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Now, she is 17.

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So how do you tell whether this is physiologically

0:42

normal or abnormal? Yeah, that is the question.

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If you look at the gland, first of all, one question would be,

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well, if we're thinking it could be a little big,

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is it because there's a mass there?

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Now,

0:55

remember we talked about the pituitary tuft and you got a

0:57

great one here. You got a stalk that's in the midline,

1:01

and so there's not going to be a mass.

1:04

So if it is big, why would that be?

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And also, well, is it big, as you said, young female.

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We know that the pituitary is a little chubby,

1:13

but can it be a little chubby in that age group?

1:15

Yes.

1:17

So this is where you have to get a little bit nitpicky,

1:19

I think, meaning measuring the gland normal, abnormal,

1:24

because there are resources out there that will tell you what

1:26

the range is. Okay, so I measured this gland at about 8 mm.

1:31

Okay. And as it turns out, this patient is 17 and a female.

1:36

Okay. So we have to decide,

1:39

is this in the normal range for that group or not?

1:42

And as it turns out,

1:44

you can see this in young females with pituitaries of this

1:47

size and the upper end of normal, but not in this age group.

1:51

Okay. This patient is 17.

1:53

When do you start to see the bump in size?

1:55

Yeah, it starts to go up.

1:57

The highest,

1:57

the biggest size that's normal is at 22 to 32 age group.

2:02

Okay, so this patient is below that.

2:03

So the upper range of normal is going to be below seven.

2:06

So, yeah, it's a little chubby by objective means,

2:11

meaning that that amenorrhea that we're talking about,

2:15

we have to start investigating that and other diagnoses

2:18

of pituitary hyperplasia. Yeah, I mean,

2:20

your first reaction when you hear that there's decreased

2:22

hormone function as a clinician or as a radiologist is, oh,

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well, maybe the pituitary is deficient, maybe it's small.

2:29

But then when you see the pituitary either normal

2:32

or a little plump, unless you're dialed in,

2:35

you could get a little bit confused.

2:37

Now, before age 21 or 22, the pituitary,

2:40

according to the charts that you've shared with me,

2:42

some very great scientific charts,

2:45

it should be about six, 6.2, maybe 6.4.

2:49

You know, this one was encroaching upon eight.

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And you don't start to see seven or eight in a woman until,

2:55

as you said, age 21, 22 or 23.

2:58

So you know it's a millimeter.

3:00

Meter or too big for a woman.

3:02

And in this scenario,

3:04

it makes you think about pituitary hyperplasia.

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So in somebody with primary amenorrhea that's a young woman,

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what would be the first thing you'd consider?

3:12

Well, amenorrhea would be one thing of pituitary hyperplasia.

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There's a list of things,

3:17

but one thing would be anorexia nervosa is one reason you

3:22

could see it. Hypothyroidism more common in women.

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And there are some other things: Addison's disease, medications,

3:29

taking estrogens, taking phenothiazines.

3:34

Okay, all those things can affect hormonal levels,

3:37

but also the pituitary.

3:38

And I can assure you that neurosurgery classic neurosurgery

3:42

board question, right, is they show you a big pituitary,

3:45

try to get you to operate on it,

3:47

and if you didn't check the thyroid, you fail.

3:50

Okay? So hypothyroidism is going to be a big one,

3:53

but in this particular setting, young female,

3:56

17-year-old amenorrhea,

3:59

I would say anorexia nervosa is going to be right up there,

4:02

but you're going to have to check these other things as well.

4:04

What's her med list look like and what's her

4:07

endocrine function? Yeah, in my experience,

4:09

I'm not a real physician like you.

4:11

I'm a radiologist, but I used to be a clinician.

4:14

And the first two things that always come to mind in this

4:16

scenario in a younger individual, especially a woman,

4:18

anorexia nervosa number one,

4:20

and then thyroid disease number two.

4:22

For those of you that are younger, your residents,

4:24

your fellows,

4:25

one way to think about it is when the end organ fails,

4:28

the pituitary says, hey, I don't have enough juice.

4:32

We got to make some more juice.

4:33

So the pituitary, like a muscle, hypertrophies.

4:37

So that's the phenomenon of pituitary hyperplasia.

4:40

So whenever an endocrine organ fails,

4:43

the pituitary can get big.

4:45

Some causes of a big pituitary without a focal

4:48

mass: pituitary hyperplasia, neurosarcoidosis,

4:54

Langerhans cell histiocytosis, or EG lymphocytic hypophysitis.

4:59

Sometimes you can get an infiltrative adenoma

5:01

where you don't actually see a mass.

5:04

Another really important one that we often overlook in adults

5:08

usually don't see it in younger women, 17 years of age,

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but say a 40-year-old woman who's a little bit bigger in

5:14

terms of body habitus is intracranial hypotension,

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so-called SIH (spontaneous intracranial hypotension),

5:21

where the CSF pressure is down and the sella enlarges to fill

5:25

that space. That looks a lot like true pituitary hyperplasia.

5:30

Pleomorphic meningiomas can be very smooth where you don't

5:33

actually see a mass. Metastases, dural AVFs,

5:37

pituocytoma, leukemia, lymphoma,

5:40

any infiltrative lesion where you don't have a true mass

5:44

within the pituitary gland can give the impression

5:47

that the pituitary is enlarged.

5:49

Shall we move on?

5:51

Let's do it.