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Hello everyone.

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Dr. Sidney Levy here.

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Today, I'm continuing our discussion of the diagnosis

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and staging of oropharyngeal squamous cell malignancy,

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using the example of a palatine tonsillar tumor.

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So, this large tumor can spread in multiple directions.

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Common methods of spread are via the

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glossotonsillar sulcus into the base of the tongue.

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So in this case, the tumor is threatening to

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do this, but if we look at the base of tongue here,

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and we come out to the tonsillar tumor,

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we can see that the glossotonsillar sulcus

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is effaced because of the size of the tumor.

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So, normally the glossotonsillar sulcus is easier

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to appreciate in this region here, but in this

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case, the tumor is very large, and it's effaced it.

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We suspect that there may be microscopic

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invasion of the base of the tongue, but we can't

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actually confirm for certain that there

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is macroscopic extension on these images.

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But that is a common method of spread.

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The other method of spread is laterally

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into the deep spaces of the neck.

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And specifically, the masticator space is one

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that we pay a lot of attention to because

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it has an important influence on staging.

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So in this particular case, the tumor,

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once again, is close to the masticator

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space, but not clearly invading it.

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Let me draw that for you

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so we're all on the same page.

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This is the masticator space here.

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We have the masseter muscle and

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the medial pterygoid muscle.

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And then we have the tumor effacing

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the parapharyngeal fat in this region.

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But we can still see the margin

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of the medial pterygoid clearly.

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So, this tumor, while close to the masticator space,

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is not clearly invading into it.

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The other direction these tumors can

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take is superiorly into the soft palate.

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And for that, a combination of the axial and

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the sagittal is probably the best way to go.

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So, just to orient you, we have the uvula

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of the soft palate here, on the sagittal.

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And then as we come out into the tumor, we can see

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that the tumor is very close to the soft palate.

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So, once again, uvula in the axial plane,

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and the uvula as we go down into the rest of the soft

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palate becomes continuous with the palatine tonsil.

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There is some concern here that the tumor is

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very close to the soft palate, and there would be

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suspicion that this is invading the soft palate.

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So that's an important consideration as well.

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The last thing I would like to finish off

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with is differentials to consider in this

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region, and perhaps the most common one would

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be palatine tonsillar lymphoid hyperplasia.

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For that, it's important to remember that hyperplasia

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is usually smooth enlargement, mild enlargement,

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and often symmetrical or almost symmetrical.

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So, it's not a consideration here because

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there is clearly a mass, and there is a large

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difference in size between the two tonsils.

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Other things to consider are lymphoma, which can be

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difficult to distinguish, but tends to have a more

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smooth margin and homogeneous signal intensity.

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And also other considerations such as

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infection, such as a peritonsillar abscess,

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or there can also be benign mixed tumors in

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this region, such as pleomorphic adenomas.

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Minor salivary gland malignancy

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tends to be uncommon in this area

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but can also be identified, usually

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by the pathologist rather than us.

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In our next vignette, I'd like to go on

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and formally stage this palatine tonsillar

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malignancy using TNM staging according to

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the most recent AJCC 8th edition guidelines.