Radiographic spectrum of adult pulmonary tuberculosis in a developed country

SETTING: Bispebjerg Hospital, Department of Pulmonary Medicine P. The referral centre of adult tuberculosis in the municipality of Copenhagen, Denmark. OBJECTIVE: To evaluate the radiographic spectrum of pulmonary tuberculosis (TB) in adults in a low-prevalence country and to correlate radiographic appearances with bacteriological results, clinical and demographic data. DESIGN: Retrospective review of medical files on 548 cases with pulmonary TB according to the criteria of WHO. RESULTS: Usual radiographic pattern of reactivating TB, with upper lobe involvement, was found in 92% (n = 504), eight percent (n = 44) showed unusual X-ray patterns for adults, such as isolated lower lobe infiltrations (n = 19), hilar adenopathy (n = 10), miliary TB (n = 7), tuberculoma (n = 2), pleural effusion (n = 1) and normal chest X-ray (n = 3). Eight-nine percent of cases with cavitary lesions were positive by microscopy. CONCLUSION: The risk of missing a diagnosis of pulmonary TB may be high if patients present with an X-ray unusual for TB, but this is fortunately seen only in 8% of cases of pulmonary tuberculosis. Unusual X-ray is more commonly found in patients with concomitant disease, such as diabetes and cancer. If chest X-ray shows cavities, but the smear is negative for Mycobacterium, TB is unlikely and further diagnostic procedures should be performed without waiting for culture results.