Pseudoallescheria boydii (Scedosporium apiospermum), cause of mycotic granulomatous osteomyelitis--case diagnosis

Abstract

Fungal bone infections constitute about 0.1-0.2% of all osteomyelitis cases. The disease, mycetoma pedis, most often affects the feet and is also known as madura foot. Mycetoma, extremely rare in this geographic area, is endemic in tropical and subtropical regions. We present a case of mycetoma pedis (madura foot). The patient was a 50-year-old woman. The clinical signs included pain, indurations, and local redness. The anamnesis was very long, about 10 years. The operative material was routinely stained with haematoxylin-eosine [HE]. Granulomatous inflammation of the bone was confirmed pathologically. All pathological characteristics pointed to a fungal infection in the form of mycetoma pedis. Special staining for fungi was performed: PAS, Grocott's hexamine-silver, and Giemsa, confirming the diagnosis of mycetoma. A definitive microbiological analysis was carried out through tissue inoculation on the Sabouraud dextrose agar laboratory media for fungal cultivation. Pseudoallescheria boydii, the sexual stage of Monosporium apiospermum, was isolated. After microbiological verification of fungal infection, surgical therapy was carried out. Seven months after the first operation, the patient had the same clinical signs. The diagnostic procedure was repeated and mycetoma was confirmed once again. Surgery was again the therapy of choice, because Pseudoallescheria boydii is resistant to treatment with antimycotic drugs.