Recrudescence of pulmonary tuberculosis: radiological and CT features in an asymptomatic Southern Italian young population.

AIM: The authors report the results observed in apparently healthy young adults undergoing chest radiography for pre-employment screening. MATERIALS AND METHODS: Between July 1996 and December 1997, 2292 young adults underwent conventional chest radiography for pre-employment screening purposes. Of these, 378 subjects (16.4%) in whom the chest X-ray showed alterations indicative for pulmonary parenchymal lesions were selected for the study. The lesions were divided into four groups: 1) single nodular opacity (n=98/378=25.9%); 2) multiple nodular opacities (n=25/378=6.6%); 3) single or multiple parenchymal consolidation(s) (n=203/378= 53.7%); 4) interstitial disease ( %). All subjects received a tuberculin skin test. The subjects in groups 1, 2 and 3 underwent the diagnostic protocol, which consisted of tuberculin skin test (TST) and CT scan for groups 1 and 2, and a repeat chest radiograph at 30 days for group 3. The subjects in group 4 were studied by high-resolution CT (HRCT). RESULTS: In group 1, CT showed nodular opacities with psammomatous calcifications in 13 cases, vascular dilatations in 3, calcified nodule in 7 subjects with positive TST, and uncalcified nodular lesions in 75 subjects (53/75 with positive TST). In group 2, FNAB confirmed the preliminary diagnosis of metastases in 2 cases; CT demonstrated the pleural origin of opacities in 1 patient, and multiple nodular lesions in 12 subjects; it invalidated the radiographic findings in 3 subjects, and demonstrated multiple nodules associated to increased interstitial thickening in 3 subjects. In group 3, the lung alterations had completely disappeared in 106 subjects, whereas in 97 subjects there was reduced extension of the previously observed lesions, but appearance of new sites of parenchymal consolidation. In group 4 CT confirmed the radiographic suspicion in 14 cases. CONCLUSIONS: Tubercular infection is currently increasing in industrialised countries. In our study it showed a relatively high prevalence of about 4.5% in a young asymptomatic population.