CT Differentiation of Anthracofibrosis from Endobronchial Tuberculosis

Abstract

The purpose of this study was to use CT to differentiate anthracofibrosis from endobronchial tuberculosis (TB), both of which are major causes of benign bronchostenosis. We retrospectively reviewed the clinical and CT findings of 49 patients with anthracofibrosis and 35 patients with endobronchial TB diagnosed on the basis of bronchoscopic, microbiologic, and pathologic findings. Forty-five patients with anthracofibrosis and 32 patients with endobronchial TB had bronchostenosis on CT and were enrolled in the analysis. Nine (20%) of 45 patients with anthracofibrosis had coexistent active TB (two, endobronchial TB; six, pulmonary TB; one, TB pleurisy), and 13 (29%) had pulmonary infections other than TB. Two patients with anthracofibrosis and coexistent endobronchial TB were excluded from the analysis. The CT findings were analyzed with emphasis on the pattern, distribution, and location of bronchostenosis and the number of pulmonary lobes involved. Anthracofibrosis was more common than endobronchial TB among elderly patients (p < 0.05). Statistically significant findings on CT were the pattern of bronchostenosis, presence of main bronchus involvement, and number of pulmonary lobes involved (p < 0.05). Bronchostenosis with anthracofibrosis usually involves multiple lobar or segmental bronchi. The main bronchus, however, tends to be preserved in anthracofibrosis. Most cases of endobronchial TB involve one lobar bronchus and the ipsilateral main bronchus with contiguity in extent. Anthracofibrosis can be differentiated from endobronchial TB on CT. Furthermore, CT is helpful in the diagnosis of anthracofibrosis before bronchoscopy is performed.