Abstract

Background: Pulmonary tuberculosis (TB) can produce unusual radiographic findings. Further, negative sputum and bronchoscopic results are common. Early diagnosis is equally as significant as treatment in the reduction of morbidity and mortality associated with pulmonary TB.

Aims: The aim of this study was to assess computed tomography (CT) findings of pulmonary TB, confirmed via percutaneous transthoracic needle biopsy (PTNB), and to correlate these findings with coexisting, underlying, lung diseases if present.

Study Design: Cross sectional study.

Methods: We selected eighty-four patients who were diagnosed with pulmonary TB by way of PTNB. Initially, acid-fast bacilli smear test results from these patients were negative. CT findings were reviewed to detect the presence of parenchymal abnormalities as follows: nodule(s) (<3 cm in diameter), mass (any masses ≥3 cm), daughter nodules, air-space consolidation, cavitation, calcification, lymphadenopathy, mediastinal lymphadenopathy, and associated lung parenchymal disease.

Results: The CT findings of pulmonary TB confirmed by PTNB included nodules in 44 of 84 (52.4%) cases; 15 of these 44 cases (34.1%) had daughter nodules. The second most common finding was masses in 24 cases (28.6%), nine of which also had daughter nodules. 16 cases (19.0%) displayed nonsegmental consolidation. Of these 16 cases, four had coexisting usual interstitial pneumonia; four others had emphysema. Two patients with a mass had underlying pneumoconiosis.

Conclusion: Nodules or a mass mimicking lung cancer were the most common findings on CT scans in patients with pulmonary TB, confirmed via PTNB. The second most common finding was airspace consolidation. Therefore, PNTB is useful for the accurate diagnosis of pulmonary TB in the following cases: airspace consolidation or mass associated with underlying usual interstitial pneumonia, emphysema mimicking lung malignancy or cases of bacterial pneumonia.