Colon cancer. Coloured scanning electron micro- graph (SEM) of carcinoma cancer cells (orange) from the human colon (large intestine). Colonic carcinoma arises in the epithelial cells lining the large intestine. These large malignant tumour cells have a rough surface due to abnormal cytoplasmic projections. They are also displaying typically chaotic and uncontrolled cancerous growth. Cancer of the colon is one of the most common cancers, especially in Western countries. Symptoms include blood in the faeces, constipation or diarrhoea, and abdominal pain. Treatment often involves surgery and anti-cancer drugs. Magnification: x4,700 at 6x7cm size. Magnification: x15,000 at 8x10 & x4.250 at"