Das Bauprinzip der Neurinome

Summary

Fibrillary-fasciculate areas of 5 acoustic and 4 spinal neurinomas were examined with an electron microscope. The tissue structure of these areas, which are typical of neurinomas, is characterized by numerous entangled cytoplasmic processes, which appear as regular lamellar systems. The cells are envelopped by generally multi-layered basement membranes and thus isolated from each other; therefore only those processes are cogged which belong to one and the same cell. In building-up lamellar systems the neurinoma cell reveals its tendency to cover other tissue structures with its plasma membrane. In cases where bundles of collagen fibres are enclosed by tumor cells in spiral turns, an analogue of the mesaxon, a “mesocollagen”, is formed. External factors acting on the cells which impose this special form and growth may thus be excluded.

The cyto-architecture of the neurinoma supports the assumption that it originates from Schwann cells. (1) Lamellar systems as described above exist, apart from neurinomas, only in spinal ganglia. There they are built up by Schwann cells. (2) The tendency of the tumor cells to envelop neighbouring surfaces must be interpreted as an abortive attempt to develop myelin sheaths. From a morphological point of view, neurinoma cells differ from normal Schwann cells only in the respect that their tendency to envelopment is not restricted to nerve axons as is usually the case in Schwann cells. Consequently, the production of cell processes often leads to a monstrous abundance. — It is pointed out that these characteristics, of the cell pattern of human neurinomas, are essentially the same as found in experimental neurinomas described by other authors.

Zusammenfassung

Die für Neurinome typischen Gewebeteile (Typ A, Antoni) von 9 Neurinomen wurden elektronenmikroskopisch untersucht. Die Gewebestruktur dieser Tumoren ist gekennzeichnet durch die zahlreichen cytoplasmatischen Fortsätze der Zellen, die, einander vielfach umwindend, regelrechte membranöse Systeme bilden. Die Basalmembranen, die z. T. in exzessiver Menge vorhanden sind, grenzen jede einzelne Zelle und ihre Ausläufer von den anderen ab. Diese für Neurinome spezifische Zellformation wird als morphologischer Ausdruck eines flächenumhüllenden Wachstums der Zellen gedeutet, das sich ansonsten nur noch bei Satellitenzellen des ZNS findet und somit die cytogenetische Verwandtschaft der Neurinomzellen mit den Schwannschen Zellen beweist.