Figure 5.

Histopathology and immunohistochemistry of abnormal villi. a) Hydropic stem villi and diminished vessels at the affected lesion of the placenta. (HE, objective ×4). The lower left empty corner shows a cystic cavity of the hydropic stem villus. b) Decrease in both number and size of vessels by the CD34 immunohistochemical staining. (objective ×4). c) Avascular terminal villi in a part of the affected area. (HE, objective ×10). d) Scatter and disappearance of immunohistochemical CD34-positive endothelial cells in the avascular terminal villi (objective ×20).