0:01

Let's move from the carotid body tumor to the

0:04

second most common of the paragangliomas of the

0:06

head and neck, and that is the glomus jugulare.

0:10

This represents between 20 and 30%

0:12

of head neck paragangliomas,

0:15

leaving the glomus vagale to about five to 10% of cases.

0:20

Once again, I want to point out some of the literature that

0:23

has come out of the Johns Hopkins Hospital

0:25

with regard to the paragangliomas

0:28

of the skull base.

0:30

This was a study in which we looked at the

0:32

incidence at which the jugular vein was invaded

0:37

by the tumors of the head and neck.

0:41

And we were specifically looking at glomus

0:43

jugulare versus carotid body tumors

0:46

versus glomus vagale tumors.

0:48

And what you can see is that it is pretty much

0:50

a rule that those tumors that grow from the

0:55

jugular foramen, the glomus jugulare tumors,

0:58

will invade the jugular vein,

1:00

and that is very reliable in distinguishing

1:03

schwannomas from paragangliomas of

1:06

the jugular foramen. However,

1:08

it is also true that glomus vagale

1:10

tumors and some carotid tumors,

1:13

though at a smaller percentage,

1:15

also may occasionally invade the jugular vein.

1:18

So it doesn't help necessarily in defining which

1:21

type of paraganglioma will invade the jugular

1:24

vein, but it does help in distinguishing it, for example,

1:28

from schwannomas or lymph node metastases or

1:32

other tumors that arise in this location.

1:35

As with the carotid body tumors,

1:38

there are multiple different classifications

1:41

of glomus jugularis.

1:44

I should mention that the fourth type of

1:46

paraganglioma that occurs in the head

1:50

neck is the glomus tympanicum.

1:53

These occur in the middle ear cavity,

1:55

and therefore they are more discussed in a

1:58

temporal bone lecture than in

2:00

a head and neck lecture.

2:02

And certainly they are not considered

2:04

carotid space tumors.

2:06

So if we look at the classification

2:08

of the glomus jugulare,

2:11

you see that we have small tumors

2:13

involving the jugular bulb,

2:14

middle ear and mastoid tumors that extend under

2:17

the internal auditory canal that may

2:19

have intracranial extension.

2:21

Then we have tumors that extend into the petrous

2:24

apex and then those that extend beyond the

2:26

Petrous apex into the clivus or

2:29

into the foramen magnum,

2:31

which is that area that we're looking at at

2:33

the skull base and in the neck region.