Uterine hyperplasia. Coloured scanning electron micrograph (SEM) of the surface of a human uterus lining (endometrium) showing simple hyper- plasia. Uterine hyperplasia is a reaction in the endometrium to excessive or uncoordinated ovarian hormone production. Surface epithelial cells proliferate in both size and number. Here, larger hyperplastic cells (green) are at centre amongst smaller normal epithelial cells (mauve). The surfaces of both are covered with microvilli projections. Other cells have long hair-like cilia (blue). The particles (orange) over the epithelium are probably secretory material (most likely mucus). Magnification: x1500 at 5x7cm. x5400 at 10x8"~LANDSCAPE"