Breast cancer. Light micrograph of a malignant tu- mour filling a milk duct in a breast (intraductal carcinoma). The cancer cells are large and darkly stained (purple), with abnormally big nuclei, indicating rapid cell division. Decomposing tumour tissue has formed a pink mass filling the duct. Calcium salts are dark red. Normal connective tissue (light pink) surrounds the duct. In the top right is an infiltration of white blood cells in response to inflammation. Breast cancer is the most common cancer among women. Stained with eosin and haematoxylin. Magnification x125 at 35mm size.