Biondi bodies in the choroid plexus epithelium of the human brain. A scanning electron-microscopic study.

Scanning electron microscopy (SEM) was used to examine choroid plexuses in the brain of two human adults aged 44 and 46, respectively, and 12 older subjects from 67 to 98 years of age. It was possible to obtain a three-dimensional view of the ring-like structures (Biondi bodies) located in the cytoplasm of choroid plexus epithelial cells in the older-age group. The filaments forming the rings were clearly visible. No such structures were found between epithelial cells. The intracellular location of the Biondi bodies and their state of preservation compared to other cytoplasmic elements suggest that they may have a destructive effect on epithelial cells of choroid plexuses. The same material was examined by transmission electron microscopy (TEM); the results obtained were in full agreement with the evidence obtained with SEM.