Difference between revisions of "Respiratory Fungal Infections - Pathology"

Revision as of 14:30, 30 June 2010

Caused by Blastomyces dermatitidis
Occurs mainly in the Americas, Middle East and Africa, occasionally in Europe
Mainly in young dogs, occasionally other species
Can involve almost any tissue after spread from lungs
Gross lesions:
- Granulomatous pneumonia
Microscopic lesions:
- Yeast fungi with thich walls in nodules with macrophages, neutrophils and giant cells

Caused by Histoplasma capsulatum
Gross lesions in lungs:
- Firm encapsulated granulomas (granulomatous pneumonia)
Microscopic lesions:
- Macrophages with inracytoplasmic yeasts
Also in other tissues

Important cause of pneumonia in humans associated with immunodeficiency states
It has been occasionally reported in young or immunosuppressed animals (e.g. Arabian foals with congenital immunodeficiency)
Grossly:
- Diffuse interstitial pneumonia
- Patches of firmness or consolidation
Histologically:
- Alveoli are filled with pale staining acidophilic material (= trophozoite and cyst forms of the organism)
It is thought that as P. carinii is often present as a latent infection, alveolar macrophages normally control the organism - a process which fails in immunodeficient states

@@ Line 14: / Line 14: @@
 [[Aspergillosis]]
-===''Cryptococcus neoformans''===
+[[Cryptococcosis]]
-*[[Yeast-like fungi|''Cryptococcus neoformans'']]
-*Causes a [[Nasal Cavity Inflammatory - Pathology#Infectious causes of rhinitis|granulomatous rhinitis]], gelatinous exudate, [[Lungs Inflammatory - Pathology#Granulomatous pneumonia|granulomatous pneumonia]]
-*Nodules or destructive masses which often result in facial swelling
-*In severe cases, extension from nasal cavity to involve skin and oral mucosa can occur
-*Can invade through adjacent structures, eg: through the cribiform plate into the brain! These cases therefore can present as a primary neurological disease.
-*Microscopic:
-**Large number of fungi and only few macrophages, lymphocytes and giant cells