Mycobacterium chelonae in a CF patient with anaplastic large cell lymphoma

A 13-year-old patient with cystic fibrosis was diagnosed with anaplastic large cell lymphoma. At the same time colonization with Mycobacterium chelonae was detected in sputum cultures. Despite massive immunosuppression, the patient did not show evidence of mycobacterial invasive disease. Colonisation persisted for 18 months after discontinuation of chemotherapy and was not detected in the 6 years thereafter. This case highlights the dilemma of differentiating between colonisation and infection if mycobacteria are found in CF sputum samples.