Electron Microscopy:
The main, and unusual, ultrastructural feature was the countless
microvillus-like cytoplasmic extensions projecting from the cell
surface and projecting into and filling intercellular spaces (Fig.
4 and 5). These were relatively long and narrow, but quite variable
in diameter. No occludens-type junctions or desmosomes were evident.
Nuclei were somewhat irregular in profile and contained one or
more fenestrated nucleoli (Fig. 4 and 5). Moderate amounts of
rough endoplasmic reticulum were present in most tumor cells (Fig.
4).
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| Figure 3. The tumor cells have moderate amounts of cytoplasm containing many profiles of RER. Many long microvillus-like projections arise from the cell surface as seen in the upper middle part of this micrograph. | Figure 4. Cross-sections of microvillus-like surface projections of variable diameter fill the intercellular spaces. No desmosomes, tight junctions or glandular lumens are evident. The nucleolus is distinct. |
