Mycotic sinusitis

Abstract

In recent years, Extramucosal Fungal Sinusitis (EFS) in immunocompetent hosts have aroused increasing interest from both clinicians and pathologists. Histopathologically, they are characterized by the presence of fungal hyphae in the lumen of the sinus with no tissue invasion. They include two different entities: the mycetoma and the atopical fungal sinusitis (AFS). The mycetoma is the most frequent and best recognized form of EFS. The clinical picture is that of a unilateral symptomatic chronic sinusitis, often painful, unresponsive to appropriate medical treatment. CT scanning is very evocative in most cases. Definitive diagnosis requires histological and bacteriological examinations of the sinus contents. Surgery is the treatment of choice. Additional antifungal therapy is not indicated unless there is fungal tissue invasion. AFS is a distinct form of EFS. It typically occurs in an atopic patient with a long story of either chronic sinusitis or recalcitrant nasal polyposis recurring after adequate medical treatment or previous sinus surgery. Histopathologically, the pathognomonic pattern shows an "allergic mucin" and scanty fragmented fungal hyphae. Culture is the only way to identify the causative agent. Management should include wide radical sinus surgery combined with long-term nasal steroids. In spite of proper medico-surgical management, the prognosis remains variable and recurrences frequently arise.