Case 1 description: (a) gross specimen; (b) low power view showing hyperplastic parakeratinized epithelium (
) and underlying cellular stroma (
) (H&E, 100x); (c) low power view showing fibrinopurulent membrane (
) and underlying cellular stroma showing few proliferating capillaries (
) (H&E, 100x); (d) high power view showing dense aggregation of plump endothelial cells (
) with little evidence of lumen formation (H&E, 400x).