Can tuberculosis and non-tuberculosis mycobacteria infections be differentiated radiologically?

Tuberculosis (TB) and non-tuberculous mycobacteria (NTM) are socioeconomically important infectious diseases. Diagnosis is supported by radiological examinations following the evaluation of clinical symptoms. Definitive diagnosis is made microbiologically or histopathologically. TB and NTM infections progress with different radiological findings such as cavitary and nodular infiltrations. In our study, it was aimed to investigate which criteria are stronger radiological determinants of which disease in microbiologically positive TB and NTM cases.

In our study, 417 cases that were positive for TB and NTM infections in the five-year microbiology laboratory were evaluated. The symptoms, sociodemographic, laboratory and radiological findings of the cases were obtained retrospectively from epicrisis information. Patients with NTM growth were examined according to ATS/IDSA NTM Infection diagnostic criteria.

There was a male sex predominance in both groups, and mean age was similar between the groups. The TB group was observed to present with more systemic symptoms, while the NTM group presented with more pulmonary symptoms. In radiological evaluation, the most common findings in both groups were nodules, consolidation, cavitation, and lymphadenopathy. The appearance of a tree in bud was also a common radiological finding in the TB group. When the two groups were compared, the presence of emphysema and atelectasis was significantly higher in the NTM group.

In the diagnosis of TB and NTM infections, after taking a detailed anamnesis, care should be taken especially in terms of NTM infections in patients with radiological parenchymal damage.