0:01

We talked about the retrotympanic white mass in

0:05

referring to the cholesteatoma. However,

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there is a differential diagnosis that encompasses

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different things when we have a retrotympanic red or

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vascular mass. Here are the things to consider.

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For a retrotympanic red mass,

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we worry about the vascular anomalies,

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such as an aberrant internal carotid

0:28

artery or a persistent artery.

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We worry about another vascular abnormality,

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which is the dehiscent jugular bulb with or without

0:38

a diverticulum. But we also consider the tumors,

0:43

including the glomus tympanicum and the glomus jugulotympanicum,

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and we'll differentiate between the two.

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There is another entity known as the hemangioma,

0:54

and although some people would consider

0:57

that to be a neoplasm,

1:00

most people feel that it really represents a venous

1:03

vascular malformation. We'll take a look at all of these.

1:08

Here we have a patient who had a

1:11

retrotympanic vascular mass.

1:13

And what one sees is a soft tissue mass which is present

1:18

over the cochlear promontory in the middle ear cavity.

1:22

This is the axial scan,

1:24

and this is the coronal scan with a marker placed,

1:30

as you can see, right along the mass.

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And you can also see the pars tensa

1:36

of the tympanic membrane.

1:38

So this is a red mass which is seen at otoscopy

1:43

through the tympanic membrane.

1:45

And this is a typical location along the cochlear

1:48

promontory of a glomus tympanicum.

1:52

This is the round window niche.

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This is the sinus tympani.

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This is the pyramidal eminence,

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and this is the facial nerve recess

2:00

to orient you to the anatomy.

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The glomus tympanicum is said to arise from the tympanic

2:06

plexus, or Jacobson's nerve of cranial nerve nine.

2:11

This is another patient who had a

2:13

retrotympanic vascular mass.

2:15

And we're seeing a post gadolinium enhanced

2:17

MRI scan in the center here.

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What you see in this case is a much larger mass,

2:24

which is at the skull base.

2:25

We're actually down at the jugular foramen this mass has

2:30

grown from the jugular foramen upward

2:34

into the middle ear cavity here's.

2:35

The ear and the tympanic membrane would be here,

2:39

and there was a retro tympanic vascular mass.

2:43

This is a glomus jugulotympanicum.

2:47

By jugulotympanicum,

2:48

we suggest that it has components which

2:51

are both at the jugular foramen,

2:52

where you would normally have a glomus jugulare,

2:55

which in general grows more inferiorly into the skull base.

3:00

Base region and you have that component which

3:03

is extending into the middle ear,

3:05

which is the tympanic portion of

3:08

the glomus jugulotympanicum.

3:11

So this is a nice diagram that was provided to demonstrate

3:16

the skull base portion with the larger mulberries

3:19

representing the glomus jugulare portion and the portion

3:24

that's ending into the tympanic membrane into the

3:27

middle ear cavity. Again, retrotympanic red mass.

3:31

This would be the tympanic portion of

3:33

a glomus jugulotympanicum.

3:39

This is another diagram showing the involvement of the

3:43

jugular foramen by the glomus jugulare and then the

3:49

extension that goes into the middle ear

3:51

for the jugulotympanicum portion.

3:55

I want to just remind you that these are paragangliomas

3:59

and the paragangliomas can occur in four places,

4:02

typically in the head and neck.

4:04

They include the middle ear cavity with the glomus

4:06

tympanicum, the jugular foramen with the glomus jugulare,

4:10

and the upper skull base in the carotid sheath for the

4:13

glomus vagale and at the carotid bifurcation

4:17

for the carotid body tumor.

4:19

These are the classic four locations of paragangliomas

4:24

in the neck. Interestingly enough,

4:26

there is a high incidence of around ten to 15% of multiple

4:32

paragangliomas and for that reason high resolution imaging

4:36

in the neck and looking bilaterally and at these multiple

4:40

sites is important when you have a patient

4:43

who has one paraganglioma.

4:45

So they are hereditary in 7% of cases, multiple, as I said,

4:49

in around 10% of the sporadic,

4:51

but 30% to 40% of the hereditary cases.

4:55

And there is a small instance of recurrence

4:58

or residual tumor after surgery.

5:00

Remember, these are highly vascular lesions and therefore we usually

5:04

don't do fine needle aspirations or biopsies,

5:07

but instead the lesion is removed

5:10

in its entirety at surgery.

5:12

There is values for somatostatin receptor scintigraphy

5:17

which allows you to identify multiple paragangliomas.

5:21

Remember that they can occur elsewhere in the body,

5:23

including in the abdominal and pelvic cavities as well as

5:26

in the chest and rarely we see them

5:29

elsewhere in the head and neck.