Fig. 3

Ultrastructural findings, ultrathin sections, electron microscopy. a Tumor cells harboring zonula adherens (arrow). b Glial intermediate filaments (*) are present in the cytoplasm of the tumoral cell and in intercellular spaces. We can observe dilated cisternae of the Golgi apparatus and the smooth endoplasmic reticulum (black arrow) and numerous microtubules (white arrow). c Tumoral cell with an intracytoplasmic cilium in transversal section (black arrow). The white arrow shows microtubules. Insert: high magnification of the cilium. d Microvilli-like structures (*) are present in lumen-like spaces between the adjacent cells. The white arrow shows microtubules. e Extracellular eosinophilic bodies. f They are moderately dense, and have a shape of convolutions whose denser lines delimit guts