0:00

We're shifting from sialodochitis and

0:03

sialadenitis to salivary gland cysts.

0:06

The most common of the salivary gland cysts is going

0:09

to be the mucus retention cysts, and that is most

0:12

commonly seen in the paranasal sinuses, although they

0:14

can occur anywhere. We see them also in

0:17

the nasopharynx quite frequently.

0:19

Other retention cysts can occur after stricture or

0:23

after calculus, particularly in the submandibular

0:26

glandular region and the floor of the mouth, and these

0:30

can be secondary to stricture of the duct.

0:34

Pseudocyst is a different entity.

0:36

Pseudocyst occurs if the duct ruptures and mucus

0:40

escapes and then no longer communicates

0:43

with the duct.

0:45

So, that is to be distinguished with sialocele, which

0:48

is salivary rest in an area of ductal trauma or bad

0:52

drainage but still communicates with the duct.

0:56

So, the difference between a pseudocyst is it's

0:58

walled off usually with fibrous tissue and no longer

1:01

communicates with the ductal system, whereas a

1:03

sialocele still communicates with the ductal system

1:07

secondary to ductal trauma in most cases.

1:14

Other types of cysts include the lymphoepithelial

1:17

cysts, which you've heard me refer to with patients

1:19

who have Sjögren's syndrome and also sometimes with lupus.

1:24

The other scenario where we see lymphoepitheliosis

1:27

is in patients who are HIV positive and/or have AIDS,

1:31

and they can have lymphoepithelial cysts and nodules, but

1:36

branchial cleft cysts may also occur within the

1:39

salivary glands, particularly the parotid gland.

1:43

And this would be the type one,

1:46

the first branchial cleft cyst occurring within the

1:50

parotid gland, dermoid cysts possibly with fat

1:55

contamination or epidermoids with bright

1:58

signal intensity on diffusion-

2:00

weighted scans or other cysts that can

2:01

occur within the salivary glands.

2:05

You can have lymphatic vascular malformations that

2:08

occur within the salivary glands, and these also

2:11

would appear as cystic lesions in the glands or in

2:16

the other portions of the neck, the extraglandular tissue.

2:20

Remember that so-called cystic hygromas, which are

2:23

your sort of macrocystic lymphatic vascular

2:26

malformations, occur in children less than two years

2:29

of age, and they will occur in the neck, usually

2:32

posterior triangle going towards the axilla.

2:36

Other cysts that we're going to talk about are

2:38

ranulas, and most of these are painless lumps

2:43

that are unassociated with inflammation.

2:47

Here we have a patient who has a cyst

2:50

that is in the parotid gland.

2:52

You look at the signal intensity; you see it's dark on

2:55

T1 and then you see it's very similar to CSF and

2:59

bright on T2-weighted scan, very bright on T2.

3:03

Now, if you look at the rim here,

3:05

it does have a little bit of a black border.

3:07

Could this be a pleomorphic adenoma?

3:10

After all, they are very bright on T2-weighted scans

3:12

and they may be dark on T1.

3:14

This is the reason why we have to proceed with

3:17

gadolinium enhancement to see where

3:19

this lesion enhances solidly,

3:21

in which case we would call it a pleomorphic

3:23

adenoma, or if it does not enhance,

3:26

except maybe a little peripheral rim,

3:28

in which case it's going to represent a parotid cyst.

3:34

This was a first branchial cleft cyst. With regard to

3:39

first branchial cleft anomalies, you can have cysts,

3:42

you can have sinus tracts, and you can have fistulas,

3:44

depending upon where it may communicate either with

3:48

the skin surface or even the external auditory

3:52

canal. And there are two different types.

3:54

There are the preauricular or preaural ones,

3:58

as well as the type two,

3:59

which will grow from the angle of

4:02

the mandible into the parotid gland.

4:04

And the type two is more common than the type one,

4:07

first branchial cleft cyst.

4:11

Here is the Arno classification of type one or type

4:16

two first branchial cleft cyst. Here is the cyst,

4:21

which is located near the pinna of the ear and does

4:24

not communicate with the external canal.

4:27

Here's the type two,

4:28

which starts out down at the angle of the mandible,

4:31

courses through the parotid gland and may

4:35

communicate with the external canal with a fistula.

4:43

Here is an Arn-type two,

4:46

first branchial cleft cyst, starts low in the parotid or

4:52

around the angle of the mandible and

4:54

proceeds through the parotid gland,

4:57

and then from there communicates

5:00

to the external auditory canal.

5:04

So, this would be Arno type two, starting low,

5:08

going through the parotid gland,

5:09

and coming up to the external auditory canal.

5:16

Here's another example of a first branchial cleft cyst,

5:21

showing absence of contrast enhancement.

5:24

It has bright signal intensity.

5:26

Could it be a pleomorphic adenoma?

5:29

Absolutely not.

5:31

Here is another one.

5:32

And on the cyst imaging, there is fluid

5:36

and a fluid level within this first branchial cyst.