0:01

This was a superficial left parotid mass that was

0:05

palpable and was being evaluated

0:07

with MRI scanning.

0:09

As you can see on the T2-weighted scan,

0:11

this is different from our previous studies,

0:14

in that it is intermediate in T2-weighted signal intensity.

0:18

It is not bright that we would normally

0:21

suspect of a pleomorphic adenoma.

0:24

It has a little bit of irregular borders,

0:26

and although it has a dark rim around it,

0:29

it has a component where that rim is lost and

0:32

looks like it's infiltrating more aggressively

0:35

into the left parotid superficial lobe.

0:38

The lesion, if we do the plane of our stylomandibular

0:43

tunnel, you can see that it is both deep and in the

0:47

superficial portion of the left parotid gland.

0:50

On the T1 sagittal, as we go...

0:56

I'm sorry. This is T2 sagittal.

1:00

You can get a little bit of a sense of the superior

1:02

inferior nature of the mass and its heterogeneity,

1:05

but predominantly being intermediate

1:09

in signal intensity, not bright.

1:18

This is a fat-suppressed T1-weighted sequence

1:22

where you see the mass and its relatively large

1:26

size in superior-inferior dimension

1:30

On the scans through the lower portion of the neck,

1:35

we do not see pathologic lymphadenopathy.

1:38

Here is a fat-suppressed T1-weighted image.

1:41

Generally for the evaluation of parotid

1:44

masses before contrast,

1:46

we should not be performing this with fat

1:49

suppression because you'll lose the ability to see

1:52

the mass compared to the normal parotid tissue.

1:54

So, as you can see,

1:55

we've suppressed the parotid gland tissue

1:58

to the point where the mass is now

2:00

iso-intense to the fat-suppressed parotid tissue.

2:06

However,

2:07

on the post-gad scans, it is useful to have the fat

2:11

suppression, so that way we can see the greater

2:13

enhancement of the mass, as well as the possibility

2:16

of any perineural spread. With perineural spread,

2:19

we'd be looking for nerves that are enhancing

2:23

abnormally. In this case,

2:25

the facial nerve is not seen to be enhancing

2:27

abnormally in the intramastoid portion of the

2:29

temporal bone, even though this mass goes

2:33

very close to our stylomastoid foramen.

2:40

Here is the post-gad of the lower portion of the

2:44

neck, which was unremarkable.

2:46

So, in summary,

2:47

we have a tumor which does not have our typical

2:51

features of a pleomorphic adenoma and has

2:55

intermediate signal intensity

2:57

on the T2-weighted image.

3:00

Because of that,

3:01

we are concerned about malignancy.

3:03

Anytime you have something that is

3:04

not bright on a T2-weighted scan,

3:06

it's malignancy until proven otherwise.

3:09

This case ended up being a carcinoma

3:12

ex pleomorphic adenoma.

3:15

They found both benign pleomorphic adenoma tissue,

3:18

as well as myoepithelial carcinoma

3:21

within the pleomorphic adenoma,

3:24

according to the pathology.