Idiopathic granulomatous bronchitis. An unusual form of known granulomatous lung diseases or an unknown disease?

We describe two patients demonstrating a granulomatous inflammation of bronchial mucosa characterized clinically by a persistent dry cough, lack of manifestations of bronchial asthma, normal level of serum IgE and serum ACE, inflamed bronchial mucosal appearance consisting of edema, erythema, bleeding and narrowing and recovering without specific treatment. Histopathological findings of the bronchial inflammation of our patients were characterized by noncaseating granuloma formation consisting of epithelioid cells and multinucleated giant cells with infiltration of lymphocytes, plasma cells and eosinophils. The bronchial granulomatous inflammation of our patients was thought to differ from that of diseases which have been known, to our knowledge, as diseases demonstrating a granulomatous inflammation of bronchial mucosa. Although the pathogenesis of the disease could not be clarified by a careful search of special staining and culturing for the infective agent, it was most suggestive of non-specific inflammation with a granulomatous response to some sort of inhaled agents.