Fungal rhinosinusitis: a clinicopathological study from South India

Fungal rhinosinusitis (FRS) is uncommon and accounts for 6-12% of culture or histologically proven chronic sinusitis. FRS may be acute or chronic. The aim of this paper was to study the histological features that contribute to the diagnosis and sub typing of FRS, using a retrospective review of all paranasal sinus mucosal biopsies from January 2005 to December 2008. The clinical features, predisposing conditions, imaging findings, and extent of the lesion were noted. The slides were reviewed with hematoxylin and eosin, Gomori's methenamine silver, and periodic acid Schiff stains. Culture reports were obtained wherever material was subjected to culture. There were 63 biopsies diagnosed as FRS (45.7%) out of 138 biopsies of chronic sinusitis in the study period. The FRS was classified as allergic in 15 (23.8%), chronic non-invasive (sinus mycetoma) in 1 (1.6%), chronic invasive in 10 (15.87%), granulomatous invasive in 19 (30%), and acute fulminant in 18 (28.5%) biopsies or surgical resections. Predisposing conditions were identified in 19 patients with diabetes mellitus as the commonest. Seventeen of the 18 patients with acute fulminant FRS had predisposing conditions. As per the results, the characteristic histological features were allergic mucin in allergic, fungal ball in chronic non-invasive, sparse inflammation and numerous hyphae in chronic invasive, non caseating granulomas with dense fibrosis in granulomatous invasive, and infarction with suppuration in acute fulminant FRS. Aspergillus sp. was the commonest etiologic agent. To conclude, predisposing risk factors were more common in invasive FRS than in non-invasive sinusitis and Aspergillus species was the most common etiologic agent.