[Uncommon caseous maxillary sinusitis of dental origin caused by Microsporum canis]

The authors report an uncommon case of maxillary sinusitis due to Microsporum canis. To their knowledge this is the first observation in which a zoophilic dermatophytic fungus which grows usually on keratin has been isolated in a dental maxillary sinusitis in human. This observation makes it possible to discuss nosologic and diagnostic features of dental caseous sinusitis and fungal sinusitis which are often or too often called aspergillosis sinusitis.