Abstract
A 75-year-old man visited our hospital complaining of a low-grade fever, dry cough, and chest abnormal shadow. Chest computed tomography revealed a nodule with a cavity in the right upper lobe. Endobronchial ultrasonography (EBUS) of the lesion suggested that the lesion was benign. Actinomyces graevenitzii was cultured from the specimen obtained by bronchoscopy using endobronchial ultrasonography with a guide sheath technique and was identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and 16S rRNA sequencing. The patient was treated with intravenous ampicillin; subsequently, his condition improved. We believe that careful observation of EBUS findings may be useful for the differential diagnosis.