Figure 6.

Lesion reconstructed from PPH case 2. (A) The gray-blue represents the endothelial cells stained with antibody directed against KDR. The yellow smooth muscle layer (open arrow) is thin, in marked contrast to PPH case 1 (Figure 4) ▶ . The distorted endothelial cell layers begin distal to the bifurcation of the vessel and can be seen through the translucent yellow smooth muscle coat. The proximal lumen (P) is lined by an endothelial cell monolayer (thin arrow). (B) Rotated and cutaway view of the same lesion. Note the severely disrupted red lumina distal to the bifurcation and the distal (D) dilatation lesions (arrows). Blue endothelial cells (open arrows) obstruct the lumina. Yellow, Smooth muscle; blue, KDR positive cells; red, lumen.