Pulmonary alveolar microlithiasis of unknown cause is characterized by familial occurrence and the deposition of laminated calcium stones within alveoli. The most specific diagnostic technique available is radiologic examination of chest by means of xerotomography. Symptoms are often absent even when involvement is massive, but since the disorder seems to be progressive and to be caused by some abnormality of calcium metabolism, it will eventually lead to symptoms of pulmonary insufficiency, perhaps with pulmonary heart disease.
The patient was a 32 year-old male in whom an abnormal lung shadow was noticed by routine roentgenographic examination almost 8 years ago. He had no symptoms except marked clubbing of fingers. Chest X-ray film showed fine sand-like particles spread uniformly through both lungs. Transbronchial lung biopsy was carried out and revealed the alveoli to contain concentrically laminated calcospherites which are completely devoid of all nuclear structure.
We believe that this is the first case of pulmonary alveolar microlithiasis diagnosed by transbronchial lung biopsy.
