0:01

Adenoid cystic carcinoma is another of the

0:04

tumors that sort of fulfills that adage

0:08

I said previously that malignancies are not

0:11

as malignant as typical malignant tumors.

0:13

Adenoid cystic carcinoma's prognosis

0:16

is generally termed in decades.

0:19

So the long-term survival is high,

0:22

but the tumor will persist in the body for

0:27

a long period of time.

0:28

In other words,

0:29

it's a tumor that you can live with for a long

0:32

period of time but hard to get rid of.

0:34

And that is because of the high

0:36

rate of perineural spread.

0:38

We say that adenoid cystic carcinoma has

0:40

a 50% to 60% rate of perineural spread.

0:44

And in the parotid gland,

0:46

that means we got to be careful about the 7th

0:48

cranial nerve and the third division

0:50

of the fifth cranial nerve,

0:51

the mandibular nerve in the region of the floor of

0:56

the mouth with the submandibular gland

0:58

and the sublingual gland. We

1:00

worry about the 7th cranial nerve,

1:01

the 12th cranial nerve, the 9th cranial nerve.

1:04

And in the minor salivary glands,

1:08

it usually is affecting the second division of

1:11

the fifth cranial nerve, the maxillary nerve.

1:15

It accounts for about 4% of all salivary gland tumors,

1:18

but a higher rate of the malignant salivary gland

1:22

tumors, particularly in the minor salivary gland tissue.

1:25

As you can tell,

1:27

there is a higher rate of distant metastases and

1:31

nodal metastases with adenoid cystic

1:33

carcinoma than, for example,

1:35

our low-grade mucoepidermoid carcinoma.

1:43

Here is a...

1:44

the two cases I showed previously where a

1:48

patient has a mass in the parotid gland and has

1:52

perineural spread up the third division of the

1:55

fifth cranial nerve through the foramen ovale

1:57

to come to the Meckel's Cave region,

2:00

where the Gasserian ganglion,

2:02

the trigeminal ganglion, resides.

2:04

And here you see another patient with perineural

2:08

spread up the 7th cranial nerve through the

2:10

stylomastoid foramen from adenoid cystic carcinoma.

2:17

This is an example of a patient who presented 20

2:22

years after the initial diagnosis of adenoid

2:26

cystic carcinoma of the hard palate.

2:30

You notice on this coronal scan that the hard

2:33

palate on the left side has

2:35

been surgically removed.

2:39

However, when we look at the coronal image,

2:43

we see this large mass

2:45

which extends through

2:50

the base of the skull at the orbit,

2:52

the base of the orbit, and is infiltrating the orbit.

2:55

Here's the normal optic nerve,

2:57

and extraocular muscles, and retrobulbar fat.

3:01

Here we have an orbit that is grossly

3:04

infiltrated by tumor.

3:06

And you can see that it goes through the orbital

3:08

roof and is abutting the frontal lobe of the left

3:14

anterior cranial fossa. How did this happen?

3:18

This tumor, although it was resected 20 years earlier,

3:22

had gotten into the nerves.

3:25

The second division of the fifth cranial nerve.

3:27

Here is our demonstration of the pterygopalatine

3:32

fossa and the pterygopalatine ganglion.

3:34

You notice that you have the branches of the

3:37

greater and lesser palatine foramina that are

3:40

innervating the teeth as well as the hard palate.

3:43

This tumor went up those nerves and then proceeded

3:48

superiorly to extend into the inferior orbital

3:51

fissure to get into the orbit.

3:54

So again,

3:55

this is along the greater and lesser palatine

3:57

foramina, up the pterygopalatine fossa,

3:59

to the pterygopalatine palatine ganglion.

4:02

And right here is where it enters through the

4:04

inferior orbital fissure to get into

4:07

the orbit and infiltrate it.

4:08

This is perineural spread of adenoid cystic

4:11

carcinoma, 20 years after the initial diagnosis.

4:16

Fascinating.

4:19

Here is a patient who had a sublingual gland mass.

4:22

And although it looks for all the world like a

4:25

well-defined tumor and bright on

4:29

T2-weighted scan, surprised us,

4:31

this ended up being an adenoid cystic

4:35

carcinoma of the sublingual gland.

4:38

And remember that in the sublingual

4:41

gland and submandibular gland,

4:42

the rate of malignancy is about 50:50.

4:45

And of those malignancies, in those glands,

4:49

they are dominated by adenoid cystic carcinoma.