LAUSR

Cystic fibrosis (CF) is the most common monogenic disease in the Caucasian population, and is potentially fatal.1,2 The major cause of morbidity and mortality is respiratory involvement, due to obstruction, inflammation and infection of the respiratory tract, which lead to epithelial damage, tissue remodeling, and terminal pulmonary disease.1,2 In recent decades, the most challenging infectious complications in CF have been caused by non-tuberculous mycobacteria (NTMB).3 These pathogens can cause significant lung disease, and may be difficult to diagnose in CF patients, due to overlapping symptoms, signs, and radiological findings. Moreover, the treatment of these infections constitutes an additional burden for patients.3 We report the first 2 cases of pediatric CF patients with lung infection caused by Mycobacterium lentiflavum (M. lentiflavum). Our first case was a boy with CF with typical symptoms, 2 CFTR gene mutations (c.1521 1523delCTTT/182