Maxillary Sinusitis Caused by Medusoid Form of Schizophyllum commune

We present a case of maxillary sinusitis in a diabetic female caused by the basidiomycete fungus Schizophyllum commune. Identification of the isolate was hampered by its atypical features. Subcultures formed sterile medusoid structures from nonclamped mycelia until spontaneous dikaryotization resulted in the development of characteristic fan-shaped fruiting bodies. Identification was confirmed by the presence of spicules formed on the hyphae and by vegetative compatibility with known isolates.