SCANNING ELECTRON-MICROSCOPY AND ELECTRON-PROBE MICROANALYSIS STUDIESOF HUMAN PINEAL CONCRETIONS

The calcareous concretions of human pineal bodies were investigated wi th scanning electron microscopy and electron probe microanalysis. The initial concretions measuring 5-7 mu m in diameter may have started at the calcified pinealocytes. They grew appositionally forming concentr ic laminations, and then the simple calcospherulites over 20 mu m occa sionally aggregated with each other. Some of them became numerous sphe rulite-aggregated concretions. Others individually grew with scallop-s haped concentric laminations ah intervals of 0.05-1 mu m and became lo bated calcospherulites up to 0.5 mm. The concretions over 0.5 mm were formed by their attachments. The major elements were Ca and P, while t races of S, Mg, and Na were detected. In the calcification and crystal lization values, the center of the concretions over 50 mu m was signif icantly higher than the periphery, while there were no differences amo ng the centers and also among the peripheries. The Ca and P amounts in the center were 30.8% and 14.2% by weight and the Ca/P molar ratio wa s 1.68; thereby the sand-grain-shaped crystals may be nearly hydroxyap atite, as reported previously.