Tenosynovitis caused by Mycobacterium malmoense in two kidney transplant recipients and review of the literature

: We report two unrelated cases of tenosynovitis caused by Mycobacterium malmoense in kidney transplant recipients. Both patients received immunosuppression and were referred to our tertiary hospital because of persisting complaints lasting >6 months not responding to corticosteroids or surgery. The mycobacterial cultures were positive for the slow-growing M. malmoense after several weeks of incubation. The patient in Case 1 was treated with a combination of surgical debridement and antibiotics, whereas the patient in Case 2 was only treated surgically. Both cases illustrate the doctor's delay in diagnosing mycobacterial infections, and remind us that nontuberculous mycobacterial infections should be part of the differential diagnosis of tenosynovitis, especially in immunocompromised patients.