11. Eumycetoma

Specimen received as swelling left foot

Gram stain is the most important stain to differentiate between Actinomyces and fungal Mycetoma (Eumycetoma). On H and E Actinomyces is hematoxyphilic i. e blue and Eumycetoma is eosinophilic i. e pink. In gram stain Actinomyces show gram positive thin filamentous bacilli while Eumycetoma it is negative. GMS stain in Eumycetoma shows broad septate hyphae. We also hv to remember to differentiate Nocardia and Botryomycosis both of which can show bacterial clumps with surrounding Splendore Hoeppli phenomenon.Culture is definitive.