Light micrograph of prostate intraepithelial neoplasia (PIN) in a prostate gland. The presence of PIN indicates a heightened risk for prostate cancer. PIN cells have hyperchromatic (dark blue) nuclei with a pseudostratified (layer-like) arrangement. The PIN cells also show blebs into the luminal space of the prostate gland (small rounded projections into the white space). The PIN cells do not invade (as would true cancer cells) and are contained within the prostate gland which itself lies within connective stromal tissue (pink-red area in bottom half of image). Haematoxylin and eosin stained tissue section. Magnification: x400 when printed at 10cm wide.