Background: Pulmonary infections by rapidly growing mycobacteria are rare in immunocompetent children.
Case characteristics: A 2-year-old boy with persistent right upper lobe pneumonia.
Observation: Bronchoalveolar lavage culture demonstrated growth of Mycobacterium atocessus.
Outcome: Complete resolution of disease with multidrug chemotherapy with imipenam, clarithromycin and amikacin.
Message: Persistent upper lobe cavitory lesions can rarely be caused by rapidly growing mycobacteria.