[The origin of acoustic neurionoma. An ultrastructural study of operated neurinoma incipiens (author's transl)].

The origin of eighth nerve neurinoma has been studied by several authors with the light microscope, particularly on serial sections of decalcified temporal bone. The microsurgical approach of small neurinomas has led the present authors to an ultrastructural study of this problem. In the cases in which the origin could be seen, the tumor appeared to arise from the ganglion vestibulare (Scarpae). This fact is correlated with the neural crest origin of the ganglion, and with its ultrastructural characteristics in the normal human.