Atypical mycobacterial spondylitis as a challenging differential diagnosis to metastatic disease of the spine: a case report.

Disseminated Mycobacterium avium complex (MAC) infection is rarely seen in patients without acquired immune deficiency syndrome. A disseminated MAC infection presenting with symptoms that mimic tumor metastasis had not previously been reported. Few disseminated MAC infections have been reported, and all image patterns in these cases indicated destructive lesions. We present a case involving a tumor-like disseminated MAC infection with spondylitis in a 68-year-old man whose symptoms started with severe lower back pain and fever. Treatment for malignancy was performed initially but soon stopped after tissue proving MAC infection. Symptoms then improved dramatically after a four-drug combined anti-nontuberculous mycobacteria treatment.