Lung and Nodal Involvement in Nontuberculous Mycobacterial Disease: PET/CT Role.

INTRODUCTION: Systematic use of (18)F-FDG PET/CT has the potential to simultaneously assess both pulmonary and lymph node involvement in nontuberculous mycobacterial (NTM) lung infection. OBJECTIVE: The aim of the study was to evaluate the role of (18)F-FDG PET/CT in the assessment of both mediastinal lymph nodes and lung involvement in NTM patients compared with active tuberculosis (TB) patients. METHODS: 26 patients with pulmonary NTM disease were selected; six consecutive patients had undergone (18)F-FDG PET/CT and data was compared with 6 active TB patients. RESULTS: NTM exhibited different radiological lung patterns with an average SUV max value at PET/CT scan of 3,59 ± 2,32 (range 1,14 to 9,01) on pulmonary lesions and a mean value of SUV max 1,21 ± 0,29 (range 0,90 to 1,70) on mediastinal lymph nodes. Pulmonary lesions in TB showed an average SUV max value of 10,07 ± 6,45 (range 1,20 to 22,75) whilst involved mediastinal lymph nodes exhibited a mean SUV max value of 7,23 ± 3,03 (range 1,78 to 15,72). CONCLUSIONS: The differences in PET uptake in a broad range of lung lesions and lymph nodes between NTM and M. tuberculosis patients suggest a potential role for PET/CT scan in the diagnosis and management of pulmonary mycobacterial disease.

Nontuberculous mycobacterial lung disease in patients without HIV infection: a retrospective analysis over 3 years.

INTRODUCTION: Nontuberculous mycobacterial lung infections are relatively common in immunocompromised patients but are now increasingly being diagnosed in immunocompetent individuals. These organisms are not always pathogenic bacteria when isolated from human samples. The identification of which isolates are contaminants or colonizers is based on internationally accepted criteria. The clinical significance of the isolation of nontuberculous mycobacteria (NTM) from respiratory specimens in Italy is unknown. OBJECTIVE: study was performed to evaluate the local epidemiology of NTM pulmonary infection in Naples in patients with positive respiratory specimens, and also to describe the clinical and radiological features of NTM pulmonary disease in immunocompetent patients with or without pre-existing lung disease. METHODS: Between December 2006 and September 2009, the clinical records and radiological examinations of 39 patients with 55 positive cultures for NTM species by sputum or bronchial wash or lavage were reviewed. RESULTS: According to microbiological, clinical and radiological criteria, our study identified 16 patients with NTM lung infection as a 'disease' group and 23 patients in a 'contamination' group but without disease. M. intracellulare (n = 7, 41.2%), followed by M. kansasii (n = 5, 29.4%) were the most common NTM found in the 'disease' group. We detected a high number of M. gordonae isolates in respiratory samples obtained by fibrobronchoscopy. CONCLUSIONS: We evaluated the clinical significance of isolations in our reference centre in Naples. Forty-one of all patients have 'disease', M. intracellulare and M. kansasii are mainly responsible. NTM species were analyzed in relation to their frequency. Assumptions were made about low pathogenic NTM isolations.