A: Acute endometritis: stromal edema (blue arrow) and severe engorgement of a small number of endometrial blood vessels (black arrows) H&E stain 100x. B: Acute endometritis: The endometrial epithelium showed localized denudation, as indicated by the black arrow. H&E stain 100x. C: Localized regions of subepithelial hemorrhage (blue arrow), together with congestion (yellow arrow) and edema (black arrow). H&E stain 100x. D: Acute endometritis: There is a moderate to mild infiltration of inflammatory cells, particularly polymorphonuclear and mononuclear cells, into the lamina propria (blue arrow). H&E stain 400x.