Granulomatous infection mimicking bronchocentric granulomatosis.

Four examples of granulomatous infection with histologic features indistinguishable from bronchocentric granulomatosis are presented. Lung biopsies in all cases showed necrotizing granulomatous inflammation confined to the conducting airways. No patient had a history of asthma, however, and eosinophils were not numerous in the biopsy specimens. Rare organisms were identified in special stains in three cases, including acid-fast bacilli in two and histoplasma in one; cultures grew Mycobacterium avium-intracellulare in one and Histoplasma capsulatum in another. Special stains and cultures were negative in one patient and the correct diagnosis of blastomycosis was established only after biopsy of a soft tissue mass 3 months following the lung biopsy. Exclusive peribronchial localization of granulomas can occur in infections and may cause confusion with bronchocentric granulomatosis. In non-asthmatic patients without tissue manifestations of allergy, therefore, the diagnosis of bronchocentric granulomatosis should be made rarely, if ever, and only after an infectious etiology has been carefully excluded.