Etiology of Broncholithiasis

¹ Section of Bacteriology
² Section of Medicine

By use of known reliable cultural technics and by special stains of histologic material, we have examined 12 broncholiths obtained from nine patients. By means of the silver chromate technic, we have been able to demonstrate bodies that have the morphologic features of Histoplasma capsulatum in five stones from five patients. By means of the gram and night blue stains we have been able to demonstrate branching filaments whose morphologic appearance is compatible with that of Nocardia asteroides in eight stones from five patients. In two stones (two patients), structures resembling both Histoplasma and Nocardia were present in generous numbers. Staphylococci were found in large numbers by culture in two stones. By means of the gram stain, they were shown to be only on the surface and were presumed to be contaminants and not the original stimulus to the deposition of calcium.