FIGURE 3.

Histopathological findings regarding the retrograde lymphatic spread of esophageal cancer cells (enlargement of the rectangular area in Figure 2B). A: Distant from the primary lesion, a single lymphatic vessel running along the lamina muscularis has been invaded by cancer cells. Intralymphatic cancer cells (arrow) are spread against the direction of backflow prevention valves (arrowheads). B: A serial tissue section reveals that intralymphatic cancer cells (arrow) skipped beyond the valves (arrowheads) without morphological destruction of the valves (hematoxylin and eosin stain). C: The endothelium is positive for D2-40, demonstrating that the depicted tissue sample is indeed a lymphatic vessel that has been invaded by cancer cells (arrow) (immunohistochemistry).