Pulmonary Alveolar Microlithiasis

Pulmonary alveolar microlithiasis (PAM) is a rare disorder of unknown etiology, characterized by the formation of tiny calcium phosphate calculi in the pulmonary alveoli. About 50% of the cases are familial, mainly in siblings, and the disease is usually diagnosed incidentally by the characteristic chest X-ray findings. We present a report of pulmo­nary alveolar microlithiasis detected in three siblings.