A Rare Case of Bronchiectasis with Mucoid Impaction Caused by Schizophyllum commune in an Immunocompetent Woman in South Korea

Abstract

Schizophyllum commune is one of most widely distributed fungal species, often found on dead and decaying organic matter. Only a few cases of S. commune infections in immunocompetent patients, including the sinus, sino-orbital, bronchopulmonary, and extra-pulmonary areas have been reported. A 52-year-old female patient presented with symptoms of cough, whitish sputum, and chest discomfort lasting approximately one month. The patient denied any relevant medical history. Chest radiography revealed a mass-like consolidation at the right lower lobe. Bronchoscopy showed thick, white-yellowish mucoid plugs on several bronchi on the right middle lobe. Transbronchial biopsy and aspiration were performed. Gomori's methenamine silver staining on a prepared paraffin block and fungal culture revealed a few scattered degenerated fungal hyphae. DNA amplification and sequencing analysis of the Internal Transcribed Spacer gene demonstrated 100% identity with S. commune; access number MK029865.1. The patient was diagnosed with bronchiectasis with mucoid impaction caused by S. commune fungal infection and recovered fully after 4 weeks of oral administration of itraconazole 200 mg twice a day. In Korea, there have been only two cases of fungal infections caused by S. commune in immunocompetent patients. The cases were allergic fungal sinusitis and sino-orbital infection. This report provides additional evidence that invasive fungal infection by S. commune is possible in immunocompetent patients.