[A case of bronchocentric granulomatosis associated with Aspergillus clusters that was difficult to distinguish from lung cancer].

A 69-year-old man was examined for investigation of a nodular shadow with calcification detected on computed tomography of the chest. He showed no features of allergic bronchopulmonary aspergillosis (ABPA), such as bronchial asthma or eosinophilia. We could not distinguish his disease status from lung cancer and performed upper lobectomy of his right lung. Pathological examination revealed bronchocentric granulomatosis (BCG) with Aspergillus clusters. Subsequent serological testing demonstrated high levels of IgE-RIST and IgE-RAST (Aspergillus) whereas anti-Aspergillus precipitating antibody was not detectable. We believe that Aspergillus clusters may have been present in this patient for several years, and the pathological findings might be manifested as an asymptomatic localized allergic inflammation. BCG is a pathological component of ABPA. This case, of a localized allergic reaction, is considered very valuable for understanding the underlying mechanism of the onset of ABPA.