The fine structure of ependymoblastoma

All cpendymoblastonia in the vermis of the cerebellum of a three-year-old girl lias been examined in the light and electron microscopes. The densely packed cells were arranged in masses, in cords around blood vessels and in rare rosettes around clear lumens. In the electron microscope, the cells are characterized by a poorly differentiated cytology except for the presence of rather prominent junctional devices and, in some rosette formations, of basal bodies. From a morphological viewpoint, the tumor cells appear remarkably similar to the cells which line the normal, embryonic neural tube.