Interactive Transcript
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Let's move from the carotid body tumor to the
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second most common of the paragangliomas of the
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head and neck, and that is the glomus jugulare.
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This represents between 20 and 30%
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of head neck paragangliomas,
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leaving the glomus vagale to about five to 10% of cases.
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Once again, I want to point out some of the literature that
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has come out of the Johns Hopkins Hospital
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with regard to the paragangliomas
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of the skull base.
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This was a study in which we looked at the
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incidence at which the jugular vein was invaded
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by the tumors of the head and neck.
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And we were specifically looking at glomus
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jugulare versus carotid body tumors
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versus glomus vagale tumors.
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And what you can see is that it is pretty much
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a rule that those tumors that grow from the
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jugular foramen, the glomus jugulare tumors,
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will invade the jugular vein,
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and that is very reliable in distinguishing
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schwannomas from paragangliomas of
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the jugular foramen. However,
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it is also true that glomus vagale
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tumors and some carotid tumors,
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though at a smaller percentage,
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also may occasionally invade the jugular vein.
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So it doesn't help necessarily in defining which
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type of paraganglioma will invade the jugular
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vein, but it does help in distinguishing it, for example,
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from schwannomas or lymph node metastases or
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other tumors that arise in this location.
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As with the carotid body tumors,
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there are multiple different classifications
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of glomus jugularis.
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I should mention that the fourth type of
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paraganglioma that occurs in the head
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neck is the glomus tympanicum.
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These occur in the middle ear cavity,
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and therefore they are more discussed in a
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temporal bone lecture than in
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a head and neck lecture.
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And certainly they are not considered
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carotid space tumors.
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So if we look at the classification
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of the glomus jugulare,
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you see that we have small tumors
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involving the jugular bulb,
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middle ear and mastoid tumors that extend under
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the internal auditory canal that may
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have intracranial extension.
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Then we have tumors that extend into the petrous
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apex and then those that extend beyond the
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Petrous apex into the clivus or
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into the foramen magnum,
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which is that area that we're looking at at
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the skull base and in the neck region.
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