MATRIX CRYSTALS IN CYTOLOGIC URINE SPECIMENS - OBSERVATIONS ON THEIR MINERAL-COMPOSITION BY ENERGY-DISPERSIVE X-RAY-MICROANALYSIS AND MORPHOLOGIC SCANNING ELECTRON-MICROSCOPY

Crystals consisting by light microscopy of organic matrix (matrix crys tals) encountered in cytologic urine specimens of 8 patients were exam ined for mineral phase components by scanning electron microscopy with energy dispersive X-ray microanalysis (SEM-EDX) and by morphologic sc anning electron microscopy (SEM) performed separately in four of the e ight cases. Whenever possible (three cases) mineralized crystals prese nt in these specimens were examined separately by SEM-EDX for comparis on of mineral phase composition with that of the corresponding matrix forms. Although by SEM-EDX components of matrix, glass and slide prepa ration media interfere with the precise estimation of the mineral phas e components, the results of this method supported by the SEM morpholo gy suggest that crystals consisting of organic matrix include a minera l phase, the lattice structure of which provides them from the early s tages of formation with the characteristic morphology of the fully min eralized forms. This also suggests that organic matrix plays a role in the nucleation of minerals during the formation of certain urinary cr ystals. (C) 1994 Wiley-Liss, Inc.