[Ultrastructure of primary or endogenous prostatic calculi. Scanning electron microscopic study].

We make an analysis by means of a Scanning Electromicroscope, of the ultrastructure of 15 Primary Prostate stones. The components identified were: Carboapatite in 14 stones, Hydorxyapatite in 3, Whitlockite in 4 and Wedellite in 2 stones. The ultrastructural findings have enabled us to classify them as follows: 1. Hydroxyapatite stones, which we call "Crystalline", the rarest, due to the predominance of the inorganic component. 2. Carboapatite stones, which possess a great deal of organic material and which we subdivide into "Amylaceous" for those which possess some ovoid formations which appear to us to correspond to amylaceous bodies and "non-amylaceous" for those without them.