[Bronchocentric granulomatosis].

Bronchocentric granulomatosis (G.B.C.) is a disorder which was considered rare till recently (67 cases published). The essential histo-pathological lesion is the presence of a necrosing granuloma in the wall of the small bronchi and bronchioles which may extend by contiguity into the adjacent pulmonary arterioles. The origin and exclusive bronchial location of the granuloma and the absence as a rule of extra-pulmonary lesions enable a distinction to be made with pulmonary vasculitis and other granulomas. It occurs in asthmatics (1/3 of cases) with a blood eosinophilia (79% of cases); a mycotic aetiology (essentially aspergillosis) is seen in 68% of cases and a hypersensitivity mechanism is probable. It may equally occur in non-asthmatic patients (2/3 of cases) often older and less frequently symptomatic; a cause is rarely found here and although the pathogenesis remains obscure a hypersensitivity reaction is likely. The radiology is similar in the two groups; typically represented by a round macro-nodular opacity or a single infiltrate in the upper lobes. The outcome is favourable in 90% of cases, either spontaneously or as a result of treatment (surgical excision or steroid therapy). Thus it is important to differentiate other pulmonary granulomas whose prognosis is much more guarded. These particular characteristics suggest that G.B.C. should be removed from the group of pulmonary vasculitides in which they were initially placed by Liebow.