Maxillary fungus balls due to Fusarium proliferatum

Abstract Fungus ball is the most common form of non-invasive fungal rhinosinusitis. Aspergillus fumigatus (between 44.8% and 75%) and Aspergillus flavus (14%) are the two most common species recovered. However, recent advances in mycological laboratory methods have enhanced the detection and identification of fungi within fungus balls. Fusarium species, sometimes recovered from other forms of fungal rhinosinusitis such as allergic fungal rhinosinusitis or acute invasive fungal rhinosinusitis, are poorly associated with sinonasal fungus ball. Here, we describe two further cases of a fungus ball due to Fusarium proliferatum and provide the first description of this fungal pathogen with a fungus ball of odontogenic origin. These case reports demonstrate that uncommon fungal species such as Fusarium spp. might be underestimated as agents of sinusal cavity fungus ball. Enhanced mycological detection and diagnostic techniques might give rise, in the near future, to the emergence of new or rare fungal species associated with this clinical entity.