Transbronchial biopsy of pulmonary alveolar microlithiasis.

A middle-aged woman was initially seen with mild breathlessness and a fine reticulonodular pattern noted on chest roentgenogram. Pulmonary alveolar microlithiasis was demonstrated by transbronchial biopsy. Although microlithiasis calcispherites have been described as appearing in bronchial walls, at necropsy, and in lavage fluid, we have found only one previous report of a case diagnosed by transbronchial biopsy.