An ER case with a surprise finding in the effusion

Coffeehouse Case Spotlight time! 

This super interesting case was posted back in 2018 by Dr. Jeff Smith. A 3 year old Yorkie was found to have pleural and abdominal effusion as well as enlarged abdominal and thoracic lymph nodes (very hypoechoic on U/S). Low alb (1.9), BUN (6), BG (65) on lab work. 

One of the lymph nodes was aspirated (first photo), and the effusion was also sampled (second photo). 

Well well well…what are THOSE doing in there??

Those small, intracellular structures with a thin clear capsule and crescent shaped nucleus are Histoplasma yeasts! This supports a diagnosis of Histoplasmosis in this dog which was affecting his lymph nodes and presumably his GI tract. It’s pretty uncommon to see these yeasts an effusion, making this an even more interesting case.