Pulmonary alveolar microlithiasis in children.

Two asymptomatic Turkish sibs are presented, a 4-year-old boy and his 7-year-old sister, with pulmonary alveolar microlithiasis (PAM) confirmed by transbronchial lung biopsy and bronchoalveolar lavage. Chest radiographs and high resolution CT demonstrated widespread intra-alveolar calcifications in both lungs. The lesions were sharply defined and less than 1 mm in diameter. CT documented a high concentration of microliths along the bronchovascular bundles, the intralobular fissure and the (sub)pleural lung parenchyma. The combination of bronchoalveolar lavage and roentgenographic appearance in high resolution CT are characteristic and pathognomonic, and can confirm the diagnosis. The more severe changes in the elder sib and the radiographic controls suggest that the pulmonary disease may be progressive in our patients. The described family of consanguineous, unaffected parents with two affected and one healthy child confirmed the autosomal recessive inheritance of PAM (McKusick 265100). In addition, the affected girl had autosomal recessive Waardenburg-anophthalmia syndrome (McKusick 206920), raising the question of whether this is a chance occurrence or possibly a contiguous gene syndrome.