Pulmonary alveolar microlithiasis--report of three cases with pulmonary function and exercise studies.

Pulmonary alveolar microlithiasis is a rare disease involving accumulation of calcific concretions in the alveoli of the lungs. Three cases of this disease are reported with their varying and unusual clinical features. Radiologic studies demonstrated presence of diffuse calcific densities in the lungs with varying degrees of emphysematous changes. Bone scans showed diffuse uptake of the tracer in the lungs. Pulmonary functions showed hyperinflation and small airways dysfunction in one case besides the presence of restrictive ventilatory defect. Exercise studies demonstrated arterial oxygen desaturation on exercise.