Fungal colonization of the paranasal sinuses.

Fungal infection of the paranasal sinuses occur in four primary types: acute invasive (1), chronic invasive (2), chronic fungus ball (3) and allergic fungal sinusitis (4). The first and second form can be fatal and is often found in immunosuppressed patients. The present paper concerns a group of immunocompetent patients with non-invasive chronic sinusitis caused by moulds. Over the period from 1994 to 1998, 132 tissue samples from the paranasal sinuses obtained by endoscopic operation from 117 patients was examined for mycotic infections. The mycological examination was carried out if granulomatous and crumbly material was seen in the sinus by endoscopy (91 times maxillary sinus, 23 times ethmoid sinus, 11 times frontal sinus, 7 times sphenoid sinus). Out of 117 patients 29 were positive (24.9%). From 132 surgical specimens fungi were proved in 34 times (25.7%). The following fungal species were isolated: Aspergillus fumigatus 17 times, other Aspergillus spp 6 times, Alternaria alternata 2, Penicillium rugulosum 1, and moulds without differentiation 5 times. In the histological examination an invasive mycelial growth in the mucous membrane or in the bones was never observable. Our findings represented a commensal colonization of the paranasal sinuses, but not a mycosis. The colonization is evidently assisted by a chronic hypertrophic sinusitis with increased mucus production which impedes the mucociliary clearance. For immunosuppressed patients, however, this situation causes a danger of invasion with fatal consequences.