[Structure of primary prostatic endogenous calculi].

A crystallographic analysis ("fine plate") is carried out on a total of 62 primary or endogenous prostate stones and the particular features of their structures are described. We observed that they present a compact nucleus consisting of just apatite or whitlockite or of mixtures of the first with other minority components, with apatite (basically carbo-apatite) being the essential component in 98.38% of the stones studied. The periphery present concentric layers, some of which are lobe-shaped, intercalated in cases of mixed periphery and in which there is a qualitative and quantitative predominance of apatite, which may be the only component of the same. The most frequent observation is the association of layers of apatite intercalated with whitlockite to which fine, oxalic or uric layers may sometimes be added. There is sometimes no apatite in the periphery in which case this is made up of layers of whitlockite either interspersed or not with other oxalic or uric ones.