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Let's shift our focus now to sinonasal malignancies.

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Sinonasal malignancies account for about

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3.6% of all aerodigestive system cancers.

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So it's not as common as, for example,

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oropharyngeal cancers or nasopharyngeal

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cancers or even laryngeal cancers.

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But they do occur with propensity

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here in the sinonasal cavity and

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for better or for worse, there are many different

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histologic types of cancers that will occur

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in the paranasal sinuses and nasal cavity.

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This is a graphic from a wonderful book entitled

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Head and Neck Surgery and Oncology by Jatin Shah.

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This is out of the Memorial Sloan Kettering

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group, and this graphic shows the rates of the

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different types of malignancies that populate

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the sinonasal cavities, and you can see that

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squamous cell carcinoma is going to be number one.

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The next most common we're gonna see is melanoma.

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And then of the minor salivary gland

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types, we have adenoid cystic carcinoma.

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There is this categorization I'll talk

1:07

about shortly in the other category of

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lots of different types of unusual cancers.

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So we're gonna go through

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these, uh, sort of one by one.

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Where do these occur?

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Well, within the paranasal sinuses, the maxillary

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antrum is the most common to have a solitary lesion.

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However, quite often it grows from the maxillary

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sinus into the adjacent nasal cavity or ethmoid

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sinus, and therefore, we have what's called the

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overlapping sites here, which is the largest category.

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So growing from the maxillary antrum into

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the ethmoid sinus or nasal cavity.

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You can, as you see, have lesions that

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are solitary within the nasal cavity.

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Again, these may be squamous

1:52

cell carcinomas or melanomas,

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most commonly. There is this Ohngren's line.

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This is a line going from the medial canthus

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to the angle of the mandible, and any tumor that

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is above, or in this case, posterior-superior

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to Ohngren's line, tends to have a worse prognosis

2:14

generally than those anterior, and that makes sense.

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As you would expect, involvement of the skull

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base, involvement of the intracranial contents,

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involvement of the orbits is going to lead to

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a worse prognosis than those lesions that are

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still confined to the paranasal sinuses or nasal cavity.

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52 00:02:30,890 --> 00:02:33,740 Again, I highly recommend this book as an excellent

2:33

reference for head and neck malignancies.

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What are the risk factors for sinonasal cancer?

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Well, it depends on the different types of cancer.

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Men generally have a higher rate than women. However,

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this may be related to occupational exposure.

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As you can see, workers that are dealing with

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nickel, chromium, or radium have a higher rate of—

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cancers, and these tend to be

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more commonly men than women.

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Woodworkers have a higher rate of adenocarcinoma.

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This exposure to the wood dust leads to the

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possibility of adenocarcinoma, and these

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adenocarcinomas may be classified as salivary

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versus non-salivary adenocarcinomas, and the non-

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salivary adenocarcinomas are further classified into

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intestinal-type adenocarcinoma (ITAC) or non-ITAC.

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The ITAC type are those that are exposed to hardwood,

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leather, and dust, whereas the non-ITAC type

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have less correlation with the occupational exposure.

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Smoking is another risk factor for sinonasal cancer.

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The presence of an inverted papilloma is a risk factor

3:48

for squamous cell carcinoma of the paranasal sinuses.

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Prior radiation for either

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previous cancers or in yesteryear—

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certain dermatologic conditions would also

4:03

have a higher rate of sinonasal cancer.

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There has been an association with HPV-positive

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exposure that is seen in some of these cancers.

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The HPV subtype, however, that is

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associated with sinonasal malignancies

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is different than the HPV subtype associated

4:25

with most tonsillar or oropharyngeal carcinomas.