ABSTRACT
Alveolar microlithiasis is a rare pulmonary disease of unknown etiology. This chapter aim to determine the incidence of pulmonary microlithiasis in lungs of RA autopsy patients, the size of corpora amylacea, and the histochemical and immunohistochemical characteristics of pulmonary corpora amylacea. It explains stages of crystalloid formation and the clinicopathological correlation of alveolar microlithiasis: the link with interstitial pneumonitis and/or interstitial fibrosis, the relation to congestive or restrictive cardiac insufficiency. Pulmonary alveolar microlithiasis and interstitial pneumonitis, or fibrosis was histologically diagnosed post mortem. Histological evidence of chronic heart failure was determined by the presence of hemosiderin-laden alveolar macrophages. Pulmonary alveolar microlithiasis is a progressive process, characterized by crystalloid formation of beta-2-Microglobulin. During this process the alveolar calcospherities progressively increase in number and size. The clinical significance of pulmonary alveolar microlithiasis is not known, but it does not seem to contribute to interstitial pneumonitis, fibrosis, or heart failure.
