Identification of fungi in fungal ball sinusitis: comparison between MUC5B immunohistochemical and Grocott methenamine silver staining

Abstract

CONCLUSION: MUC5B immunohistochemical staining was a valuable method for identifying fungi in fungal ball sinusitis, especially in distinguishing aspergillus and mucor. Combined infection with Aspergillus and Mucor fungi was the most common pattern in fungal ball sinusitis. OBJECTIVE: To assess the value of MUC5B immunohistochemical staining in identifying fungi in fungal ball sinusitis by comparing it with conventional Grocott methenamine silver (GMS) staining. METHODS: GMS staining and MUC5B immunohistochemical staining were used to identify fungi in mucopurulent cheesy or clay-like tissues from sinuses in 180 fungal ball sinusitis patients, and the examination results were compared. RESULTS: In 180 samples of fungal ball sinusitis, GMS staining showed Aspergillus in 130, Mucor in 88, and Candida albicans in 6, while MUC5B immunohistochemical staining identified Aspergillus in 166, Mucor in 172, and Candida albicans in 16. The fungal detection rate for MUC5B immunohistochemical staining was markedly greater than that for GMS staining (p < 0.01). This implies that MUC5B immunohistochemical staining was more sensitive than GMS staining in identifying fungi in fungal ball sinusitis. Mixed infection of Aspergillus and Mucor was present in 146 of 180 patients (81.1%).