Pleuritis Caused by Mycobacterium kyorinense without Pulmonary Involvement

We herein describe the first known case of pleuritis caused by Mycobacterium kyorinense without pulmonary involvement. A 48-year-old man undergoing immunosuppressant therapy presented with cough and dyspnea. An accumulation of pleural fluid was noted; however, computed tomography revealed no pulmonary lesions. Cultures of the fluid yielded non-tuberculous mycobacteria, which was identified as Mycobacterium kyorinense. The patient recovered after 6 months of therapy with clarithromycin and moxifloxacin. Clinicians should be aware that Mycobacterium kyorinense can cause pleuritis without pulmonary involvement. When mycobacterial species are isolated from the pleural fluid, precise identification and drug susceptibility testing are warranted.