Giant cells in tumors associated with tuberous sclerosis

Electron microscopic studies of giant cells which appeared in tumors associated with tuberous sclerosis revealed an abundance of cytoplasm with large numbers of organelles and intermediate filaments, but not neurotubules or synaptic complexes. Furthermore, the presence of cilia, microvilli, formations of microrosette-like structures and complicated interdigitation of the folded processes of adjacent cells were confirmed. Immunohistochemical investigations of the cells showed positive reactions against GFAP-antiserum. It was concluded that the giant cells were of glial origin, predominantly having a potential to differentiate to ependymal cells.