Laryngeal SCC - Cartilage Invasion
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Hello everyone, Dr. Sydney Levy here.
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3 00:00:05,260 --> 00:00:08,050 I'm continuing our discussion of the assessment
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of laryngeal squamous cell malignancy, using our
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example of this large transglottic malignancy
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involving all three subsites of the larynx.
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I'm currently at the supraglottic level, and in our
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previous vignette, we discussed, among other things,
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the general features of these malignancies and how
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we can assess whether cartilage is involved or not.
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In this vignette, I'd like to talk about some of the
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other important anatomical structures, particularly
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in the supraglottis, that we need to be aware of.
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And I would like to begin by mentioning the
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paraglottic space and the pre-epiglottic space.
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Paraglottic space.
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Because they are important landmarks to help
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establish whether a laryngeal tumor has breached
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the mucosa and is able to access cartilage
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or move between one subsite and another.
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So to look for the paraglottic spaces, or FAT,
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you need to be at the level of the false cords.
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So to orient, in this patient, it is a
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bit difficult, but at this level, we're
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at the level of the aryepiglottic folds.
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And then, a few slices further, we start to
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see a fat plane forming between cartilage
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externally and false cords internally.
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Now in this case, the paraglottic fat is preserved
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on the left, but it is effaced on the right.
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So let me draw that for you.
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This is how it should appear.
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This is infiltrated fat.
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Now at the same level, anteriorly, above the level
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of the true vocal cords, so above the anterior
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commissure, we have the pre-epiglottic space.
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And once again, you should be
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able to see fat in this region.
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And in this patient, the
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pre-epiglottic space here is obscured.
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So both the right paraglottic and the
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pre-epiglottic spaces at the level of the
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supraglottic larynx are involved in this
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patient with a large transglottic malignancy.
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It's important to note that once the pre-epiglottic
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space is involved, the tumor can extend outside the
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larynx through normal anatomical spaces such as the
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thyrohyoid notch or around the cricothyroid ligament.
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Or in this case, in this advanced malignancy,
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it can just extend right through the inner
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and outer cortices of the thyroid cartilage.
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In cases like this, it's important to have a CT as
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an adjunct because it may assist with determining
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the integrity of the cartilages at this level.
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But one important caveat with CT is that
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the presence of sclerosis of cartilage
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is not in and of itself indicative
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of cartilage involvement.
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So if you see sclerosis, but you don't see cortical
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destruction, you should not say that the patient
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clearly has tumor involvement of their cartilage.
Sidney Levy, PhD, MBBS
Radiologist and Nuclear Medicine Specialist
I-MED
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