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 result
ed in the development of characteristic fan-shaped fruiting bodies. Identif
ication was confirmed by the presence of spicules formed on the hyphae and
by vegetative compatibility with known isolates.