Figure 5
Case 4: (a) Electron micrograph showing two tumor cells that remain barely attached by a few small, poorly developed cell junctions. The cytoplasm is abundant and the nuclei are markedly irregular and each contains a large nucleolus. The cell membranes are covered by numerous, slender microvilli. (b) Binucleated tumor cell showing markedly irregular nuclear contours. One nucleus has two large nucleoli. The apical and lateral portions of the cell membrane are covered by a large number of microvilli. (c) Multinucleated giant tumor cell. The nuclei are irregular and some contain more than one nucleolus. The cytoplasm is abundant and shows a relatively large number of mitochondria. The cell membrane appears to be covered by microvilli. (d) Two of the tumor cells have a large intra-cytoplasmic lumen. The one on the left contains a small amount of electron dense material, which probably represent proteoglycans. The cell membrane that borders the intra-cytoplasmic lumen of the cell on the right is covered by short microvilli. The cytoplasm of the cell in the lower part of the figure contains abundant bundles of intermediate filaments, which most probably represent keratin (a, × 6000; b, × 14 000; c, × 5500; d, × 6000).
