Radiographic spectrum of adult pulmonary tuberculosis in a developed country

Bispebjerg Hospital, Department of Pulmonary Medicine P. The referral centre of adult tuberculosis in the municipality of Copenhagen, Denmark.

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.

Retrospective review of medical files on 548 cases with pulmonary TB according to the criteria of WHO.

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.

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.