Bronchocentric Granulomatosis (BCG)
Bronchocentric granulomatosis (BCG) is a necrotizing granulomatous inflammatory process that is centered on bronchi and bronchioles and results in focal or complete destruction of their walls.

BCG is not a specific disease but rather a type of inflammatory reaction pattern due to a variety of non-infectious and infectious causes.

Non-infectious cases predominate; most are a manifestation of allergic bronchopulmonary fungal disease, usually aspergillosis. Patients frequently have a history of chronic asthma and may exhibit blood and tissue eosinophilia. Bronchocentric granulomatous inflammation may exhibit prominent palisading of histiocytes and may be accompanied by intralumenal exudate and eosinophilia. In these cases BCG may be accompanied by other manifestations of allergic bronchopulmonary fungal disease including eosinophilic pneumonia, mucoid impaction of bronchi and asthmatic bronchitis. 

Other non-infectious causes include Wegener’s granulomatosis, rheumatoid arthritis and foreign body aspiration.

Bronchocentric localization of granulomas may occur in mycobacterial infections and in a variety of fungal infections including histoplasmosis, coccidioidomycosis, North American blastomycosis and others.

In all cases of BCG the possibility of an infectious etiology should be thoroughly investigated. In individuals with a history of asthma and/or eosinophilia the possibility of  allergic bronchopulmonary fungal disease should be strongly considered. The presence of vasculitis, microabscesses, and non-bronchocentric foci of basophilic necrosis should suggest the possibility of Wegener’s granulomatosis. In many cases of BCG the cause remains  undetermined.

Photomicrographs of Bronchocentric Granulomatosis