examples of caseous granulomatous dz

[MudPhud20XX]

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So FA says the examples of caseous granulomatous dz are TB and fungal infection. Then I was just watching DIT saying that fungus gives you non-caseating granuloma which can be differentiated from TB. So which one is correct? Can anyone clarify this pls?

 

[Tajima]

DIT is wrong

Fungal infections can cause caseating, necrotic granulomas.

A definitive diagnosis would require microscopic examination of a biopsy, or PCR of the biopsy.

 

[jqueb29]

FA over DIT every single time

 

[Entadus]

DIT is wrong

Fungal infections can cause caseating, necrotic granulomas.

A definitive diagnosis would require microscopic examination of a biopsy, or PCR of the biopsy.

Agreed. Examples of NON-caseating granulomas would be Sarcoidosis and beryllium toxicity.

 

[AZ7]

Accumulation of lipoid material (recall the sterol components in fungi) from the necrosis of fungi gives the cheese like appearance. Definitely Caseous.

 

[navigator]

Question - I thought caseous granulomas were mainly from infection-related etiologies, i.e. TB, tularemia, Leprosy, etc. Therefore, I categorized all non-infectious granulomas (i.e. berryliosis, sarcoidosis, hypersensitivity pneumonitis, Crohns, etc) were noncaseating bc there's no recruitment of cytotoxic T cells to kill infected macrophages

... BUT THEN I noticed (from Pathoma) that rheumatoid nodules are also a subcategory of caseous granulomas of non-infectious etiology. Is this an exception to the rule? Or was my rule of thumb (that generally infectious etiologies -> caseating granulomas) wrong in the first place?

 

[navigator]

Sorry, allow me to clarify on my earlier point. The rule of thumb is that infectious etiologies that stimulate cell-mediated immunity (causing CD8+ cytotoxic T cell recruitment) -> necrotizing granulomas. If the infection doesn't cause a cell-mediated response, or results from a weakened cell-mediated response, such as Listeria (= basically a disease of low cell-mediated immunity, which we see in elderly and pregnant women) or M. leprae, we'd see non-caseating granulomas.

FA 2018 also corroborates this, "Caseating necrosis is more common with an infectious etiology (eg, TB)."

Infectious etiologies do not = caseating granulomas.

For example, the following conditions all result in non-caseating granulomas

Bartonella Henselae
Listeria Monocytogenes (Granulomatosis Infantiseptica)
Schistosomiasis
Mycobacterium Leprae

 

[073116]

So FA says the examples of caseous granulomatous dz are TB and fungal infection. Then I was just watching DIT saying that fungus gives you non-caseating granuloma which can be differentiated from TB. So which one is correct? Can anyone clarify this pls?

DIT is crap. FA is everything.