Allergic fungal sinusitis: incidence and clinical and pathological features of seven cases.

Allergic fungal sinusitis, like allergic bronchopulmonary fungal disease, is a noninvasive inflammatory process. It manifests as recurrent nasal polyposis. Histologically the characteristic feature is the presence of thick mucin with dense collections of degenerating eosinophils and Charcot-Leyden crystals (allergic mucin). Demonstration of fungal hyphae in allergic mucin is diagnostic of the disease. We reviewed 85 cases of nasal polyposis operated upon during a period of four years. Allergic fungal sinusitis was diagnosed in seven (8.2%) cases on the basis of presence of allergic mucin and fungal hyphae. History of previous nasal polypectomy was present in four of the seven cases, and in six of the remaining 78. There were no clinical or radiological features that could distinguish the cases of allergic fungal sinusitis from the rest. Aspergillus fumigatus, Mucor and Cladosporium were cultured from one case each.