Pop Quiz #113
The correct answer is A. Actinomyces israelii.
Actinomyces israelii is a filamentous, gram-positive, anaerobic, and non-acid-fast rod that typically presents as fluctuant nodules classically at the angle of the jaw (“lumpy jaw”) with fistulas and draining sinuses. Histologically, there are central basophilic "sulfur granules" with eosinophilic peripheries and surrounding granulomatous …