Calcification in a pineal tumour studied by transmission electron microscopy, electron diffraction and x-ray microanalysis.

The calcification in a totally calcified pineal tumour was studied. Transmission electron microscopy indicated that the tumour was a pinealoma. The type of calcification was investigated by bright-field and dark-field transmission electron microscopy in addition to electron diffraction and electron-induced x-ray fluorescence. The calcified material consisted predominantly of amorphous calcium phosphate. The type of calcification differs from the normal calcification present in pineal acervuli which consists of crystalline hydroxypatite.