Pulmonary alveolar microlithiasis and probe-based confocal laser endomicroscopy.

Pulmonary alveolar microlithiasis (PAM) is a rare disease in which calcium-phosphate microliths accumulate within the alveolar space. We report cases of 2 siblings with PAM, presenting differently as regards the distribution and clinical severity. Immune cytologic analysis of bronchoalveolar lavage showed a CD4 alveolitis in the radiologically most affected patient, whereas the least affected had a normal bronchoalveolar lavage analysis, demonstrating the low specificity of immune cytologic lavage analysis in diagnosing familial PAM. For the first time, we describe the endoscopic findings using a probe-based confocal laser endomicroscopy.