Rapid diagnosis of sputum negative miliary tuberculosis using the flexible fibreoptic bronchoscope

Acid fast bacilli are seldom identified by direct staining of sputum smears in patients with miliary tuberculosis, so that delays in diagnosis are common. We report 41 patients with miliary tuberculosis who had negative sputum smears and who underwent bronchoscopy, bronchial brushing, and transbronchial biopsy. In two patients the procedure was repeated. A definitive diagnosis was obtained from bronchoscopy in 34 patients (83%). Bronchial brushings yielded Mycobacterium tuberculosis in 24 of 42 bronchoscopies (57%), 13 from direct smear and a further 11 from culture only. Transbronchial biopsies were diagnostic in 30 of 41 procedures (73%), 28 from histological appearances, one from direct smear of the biopsy specimen, and another exclusively from culture. A rapid diagnosis was established in most patients (27/34), either by direct smear of brushings or biopsy specimens only (5), by histological examination only (14), or by both direct smear of brushings and biopsy specimens only (5), by histological examination only (14), or by both direct smear of brushings and histological examination (8). The diagnosis was confirmed later in a further seven patients by culture of brushings or specimens; in five of these non-caseating granulomas were initially found by histological examination. Fibreoptic bronchoscopy is a valuable technique for rapidly establishing the diagnosis of miliary tuberculosis.