Mycobacterium marseillense lymphadenitis: A newly identified strain in the pediatric population

•We report a case of NMT lymphadenitis in a previously healthy 4-year-old girl caused by Mycobacterium marseillense, a newly recognized strain belonging to Mycobacterium avium complex.•To our knowledge, there are sparse data in the literature regarding M. marseillense lymphadenitis in children. Since this is a rare and newly described mycobacterium, little is known about the spectrum of disease associated with infection.•The present case demonstrates that, although rare, this strain should be taken into consideration in children with lymphadenitis due to Mycobacterium.•Additional case reports may broaden our understanding of clinical disease spectrum of these new species of mycobacteria and identify optimal management and treatment of such cases.