Mycobacterium malmoense cutaneous infection in an immunocompetent patient

Background. Mycobacterium malmoense is a mycobacterium rarely described as a human pathogen. We report the first case of cutaneous infection in an imm unocompetent patient. Case report. A 75-year-old woman presented with a cutaneous nodula on the b ack of her left hand. Histology of the node biopsy showed non caseating gra nuloma with giant and epithelioid cells. Acid-fast bacilli were isolated at direct smear and after culture. Mycobacterium malmoense was identified. Th e lesion has healed after surgery. Discussion. Mycobacterium malmoense is an environmental mycobacterium isola ted from soil and water. Typically, most patients with Mycobacterium malmoe nse infections are old people with previously lung disease. A few cervical lymphadenitis in children and rare cases of tenosynovitis of the hand have been reported. Disseminated infections with cutaneous lesions have been exc eptionally described in immunocompromised patients. Mycobacterium malmoense is slow growing and its identification is hard, sometimes requiring molecu lar analysis. Probably it's the reason why we present the first description of a cutaneous infection in an immunocompetent patient. This case indicate s that Mycobacterium malmoense is also a cutaneous pathogen.