0:01

After paragangliomas and neurogenic tumors,

0:05

the most common of the benign tumors of the

0:07

carotid space are meningiomas. Now,

0:10

these meningiomas are usually

0:12

skull-based meningiomas,

0:13

not tumors that are primarily arising within

0:16

the head and neck. Here are, for example,

0:19

some cases of skull-based meningiomas,

0:23

which you see have nice dural tails

0:25

growing into the jugular foramen,

0:28

and from there growing down into the carotid sheath.

0:33

So it would not be a primary neck

0:37

meningioma, very often non-cranial meningiomas,

0:43

are more commonly occurring in the sinonasal cavity

0:48

than in the lower neck or the carotid sheath.

0:51

So this is secondary spread from a skull-based

0:54

meningioma down into the carotid space.

0:58

Jugular foramen and cerebellopontine angle cistern

1:02

lesions may occur and extend into the carotid space,

1:08

but these are generally right at the skull base when

1:12

we look at tumors that arise extracranially.

1:16

And we're talking about meningiomas.

1:19

So the meningioma that occurs at the jugular foramen

1:23

or the cerebellopontine angle cistern that grows into

1:26

the carotid space is considered a secondary

1:30

involvement of the extracranial space.

1:32

But those that occur primarily within the

1:35

extracranial space are uncommon. And as I mentioned,

1:38

the most common locations are the sinonasal cavity,

1:41

the middle ear, the temporal bone.

1:44

These are unlikely to affect the carotid

1:48

sheath structures; however,

1:49

those that arise within the parapharyngeal space.

1:52

And by this, we're talking about the

1:54

prestyloid parapharyngeal space,

1:57

not the poststyloid carotid space.

2:00

These may grow from the prestyloid parapharyngeal

2:04

space to involve the carotid sheath.

2:06

These are generally associated with

2:08

neurofibromatosis type two when

2:10

they're extracranial,

2:11

much less common than the spread from an

2:14

intracranial meningioma down

2:16

into the carotid sheath.