Abstract
A 61-year-old woman, hospitalized for a persistent cough and dyspnea, had no history of bronchial asthma, but was undergoing chemotherapy for methotrexate-related lymphoproliferative disorder due to rheumatoid arthritis. Her peripheral blood eosinophil count was significantly increased, and chest CT revealed left lower lobe atelectasis and high-attenuation mucus. Bronchoscopy revealed mucous plugs and pathological examination revealed numerous eosinophils and filamentous fungi. Allergic bronchopulmonary mycosis (ABPM) caused by Scedosporium apiospermum was diagnosed using culture and genetic analyses. Treatment with corticosteroids and antifungal drugs led to improvement. ABPM caused by S. apiospermum is extremely rare, emphasizing the importance of species identification.