Scanning electron microscopy of human prostatic corpora amylacea and corpora calculi, and prostatic calculi.

Ultrastructural studies of human prostatic corpora amylacea and corpora calculi, and prostatic calculi were conducted in order to delineate their etiology and pathogenesis. Scanning electron microscopy was employed in conjunction with histology and transmission electron microscopy in the study of prostatic tissues and concretions obtained from 21 individuals. Results confirmed that desquamated acinar cells contribute to the formation and growth of corpora amylacea. A variation in density of the matrix of the matrix of the corpora produces a laminated structure. The deposition of hydroxyapatite crystallites in corpora amylacea leads to the formation of corpora calculi. Further growth and mineralization of corpora calculi lead to the development of the more clinically significant prostatic calculi. Small spherical aggregates (from 0.5 to 5 micron in diameter) of hydroxyapatite crystallites are a prevalent constituent of the corpora and prostatic calculi. Similar spherical aggregates of hydroxyapatite crystallites have also been identified in urinary calculi and other pathologic tissues suggesting similar mechanisms of mineral precipitation.