The changing face of paranasal sinus fungus balls.

Objectives: We describe the clinical, radiographic, and histopathologic characteristics of fungus balls.

Methods: We performed a retrospective review of 24 consecutive patients with the diagnosis of a paranasal sinus fungus ball (mycetoma) from 2001 to 2008.

Results: We found that 18 of the 24 primarily involved sinuses had bony thickening, and 13 of the 24 had notable dilatation of the ostium. Eleven of the 24 patients were found to have some degree of immunocompromise (from organ transplantation, diabetes, etc). The patient's immune status correlated with the type of fungus involved. (Mucor-like fungi were more common in immunocompetent patients, and aspergillus-like fungi were more common in immunocompromised patients.) Also, there was a predilection for immunocompetent patients to have dilatated ostia, whereas immunocompromised patients were more likely to have a nondilatated ostium (p = 0.019).

Conclusions: Our series of paranasal sinus fungus balls defines a group of patients heretofore poorly described in the literature. Our data reveal an increased incidence in immunocompromised patients. We also found consistent radiographic patterns, correlations between immune status and the fungal pathogen, correlations between ostial enlargement and immune status, and the presence of cranial nerve pareses. These represent new findings that merit further study.