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As mentioned earlier, one of the causes of a

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hyperdensity within the perinasal sinuses and low

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signal in T2 weighted scan could be fungal sinusitis.

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Now, when I use the term fungal sinusitis, it's a

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very broad term, and over the course of the last

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few decades, the understanding of the different

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potential aggressiveness to fungal sinusitis

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has led to these categories of disease.

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There is non-invasive fungus ball or mycetoma.

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By non-invasive, we mean it's not really growing into

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the submucosa of the sinus and remaining a superficial

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infection, and this is the so-called mycetoma or

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fungus ball, not usually seen as something that is

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threatening in an immunocompromised individual.

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More commonly what we see at Johns Hopkins is the

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non-invasive form of allergic fungal sinusitis.

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This is a patient who has an allergic reaction

1:04

with eosinophilia, and you see polyps.

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You see enlargement of the sinus,

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as it often is bilateral.

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And although it's really a lot of opacification

1:14

of the sinus, it is non-invasive.

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It's not likely to lead to an aggressive infection.

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Contrast that with the invasive fungal sinusitis.

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The acute invasive fungal sinusitis is

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often seen in individuals with diabetic

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ketoacidosis and immunocompromised situations.

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This is where we have such infective

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agents as mucormycosis or aspergillosis.

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These can aggressively affect the sinus.

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They can lead to necrosis of the mucosa.

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They can lead to spread into the orbit, spread

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into the cavernous sinus, and even lead to

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angioinvasive or vasculitic fungal sinusitis.

1:59

In those individuals who have chronic invasive

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sinusitis, usually it's a longstanding process

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of a patient who has chronic rhinosinusitis,

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but persistence of this fungal infection.

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And once again, it may be the type of infection

2:15

that can erode the wall of the perinasal sinus.

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The fifth variety of fungal sinusitis is

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one that we do not usually see in America,

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and that is something called chronic

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granulomatous invasive fungal sinusitis.

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We actually have granulomas akin

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to tuberculosis, for example.

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This is more common in Africa or Southeast Asia,

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and it's more commonly associated with Aspergillus

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flavus, one of the varieties of aspergillosis.