Relations between subcellular events in the degenerating notochord and histopathological features of the spinal chordomas.

The authors focused their attention on the cytology of the degenerating notochord at the level of the vertebral anlagen and compared it with data of the literature on the histopathology of the spinal chordomas. The purpose of the research was to investigate the notochordal histological features justifying the fact that the remnants of a structure destined to atrophy during prenatal life, maintain a proliferative potential in postnatal life. Therefore, from the earliest stages (24th incubation hour) to the terms of development, the notochord was studied by electron microscope in chick embryo. The data obtained show that, in most notochordal cells, signs of metabolic damage and progressive degeneration coexist with signs of secretory and mitotic activity, from which the proliferative potential of these cells seems to derive. Vacuolar degeneration is also likely due to the progressive metabolic segregation of the notochord, owing to the absence of blood-vessels and the appearance of perichordal sheath.