The hematoxylin-eosin–stained sections revealed a prominent necrotizing granulomatous inflammation in the dermis, with numerous spherical capsulated organisms with pale-pink outlines and clear spaces representing endospores within multinucleated giant cells. Special stains, including methenamine-silver and periodic acid–Schiff, showed structures that were consistent with Prototheca organisms. Fite stains were negative for acid-fast bacilli, and a gram stain was negative for bacteria.
Erythematous Papules on the Leg—Diagnosis. Arch Dermatol. 2006;142(7):921-926. doi:10.1001/archderm.142.7.921-f