A case of pulmonary alveolar microlithiasis.

Pulmonary alveolar microlithiasis (PAM) is a rare disease with unknown etiology and pathogenesis. It is characterized by diffuse, innumerable, and minute calculi, called microlithiasis in the alveoli. More than half of reported cases are asymptomatic at the time of diagnosis. We describe the first case of PAM in Korea. A 19-yr-old man without respiratory symptoms presented with interstitial thickening on the chest radiograph. His chest high resolution CT scan showed diffusely scattered, ill defined tiny micronodules and interstitial thickening. Open lung biopsy confirmed the diagnosis of PAM. He was followed up for 6 months without treatment, and no progression was noticed.