Abstract
We herein report a case involving a 64-year-old Japanese woman with a pulmonary Mycobacterium abscessus infection complicated by reactive AA amyloidosis, which, to our knowledge, has not been reported to date. The patient underwent gastrointestinal endoscopy for diarrhea during the treatment of pulmonary M. abscessus infection and was diagnosed with AA amyloidosis according to the histopathological findings from the endoscopic specimen. She died four months later. The prognosis of AA amyloidosis associated with pulmonary M. abscessus infection may be very poor, and physicians should pay attention to this rare condition when difficult-to-treat diarrhea occurs in patients with pulmonary M. abscessus infection.