Abstract Pulmonary alveolar microlithiasis (PAM) is a rare autosomal recessive disorder, characterized by the deposition of calcium phosphate microliths within the alveolar spaces. We report two asymptomatic siblings with PAM in whom the diagnosis was confirmed by histology via transbronchial biopsy. As usual there was discordance between the good clinical condition and the remarkable radiological picture. Conventional radiography demonstrates sand-like appearance in both cases and CT confirms the presence of diffuse high-density micronodules and reticular lines throughout both lungs. It was found interesting that in both patients a diffuse symmetrical increased uptake of 99mTc-MDP along the cortical margins of the diaphyses of the extremities, corresponding to hypertrophic osteoarthropathy, were imaged on the radionuclide bone scans. To our knowledge such kind of finding has not been described before.