Pneumonia caused by Schizophyllum commune in a patient with diabetes: A case report and comprehensive literature review

Schizophyllum commune (S. commune) is a basidiomycete bracket fungus that rarely causes invasive fungal infections. It is often misdiagnosed as other invasive fungal disease because of its atypical clinical features. Here we report a case of pneumonia due to S commune and review the relevant literature. PATIENT CONCERNS AND DIAGNOSES: A 55-year-old male with a history of diabetes and poor glycemic control presented with cough and sputum for half a month. Laboratory examination showed elevated peripheral blood eosinophils, bronchoalveolar lavage fluid eosinophils and increased serum total immunoglobulin E. Chest computed tomography revealed a gloved finger sign and consolidation in the middle lobe of the right lung and the upper lobe of the left lung. Bronchoscopy revealed thick white mucous plugs in the left lingular bronchus, which could be removed partially by suctioning. The culture of bronchoalveolar lavage fluid and bronchoscopy brush specimens grew cottony white mold in sabouraud dextrose agar. Pneumonia caused by S. commune was diagnosed based on clinical features and microbial methods. INTERVENTIONS AND OUTCOMES: Voriconazole combined with inhaled budesonide and formoterol (inhaled corticosteroids + long-acting β-2 receptor agonist) were given, and his symptoms improved. The count of peripheral blood eosinophils and serum total immunoglobulin E decreased after 1 month. Repeated chest computed tomography showed remarkable improvement over the previous lesions. LESSONS: Although rarely reported, infections in the lungs caused by S commune should be reminded especially in patients with immunocompromised. This case illustrates the risk factors, clinical symptoms and imaging features of the pneumonia caused by S. commune. It also further highlights the diagnosis and treatment of this disease through reviewing relevant literature.