Mineralogical analysis of sputum lith from an apparently healthy subject

The sputum lith, 1 to 3 mm in diameter, were examined by microanalyser and by the method of X-ray diffraction, which revealed that the lith was composed of calcium carbonate and calcite in crystalline style. A composition of bronchial liths is often associated with different underlying diseases so that these nondestructive analyses seem to provide useful information for differential diagnosis. The present case is the first one to expectorate bronchial lith without marked pulmonary diseases.