Abstract
The patient was a 72-year-old man with a history of kidney transplantation and long-term administration of methylprednisolone and immunosuppressants who underwent resection and reconstruction of a brachial artery aneurysm. A pathological examination confirmed mycobacteria, indicating an inflammatory aneurysm with amyloid kappa light chain deposition caused by intracellular nontuberculous mycobacterium. To our knowledge, this is the first demonstration of an inflammatory brachial artery aneurysm with amyloidosis caused by nontuberculous mycobacterial infection. When a nontuberculous mycobacterial infection is diagnosed, it is important to take into account the potential development of aneurysms at locations outside of the lungs.