Kidney cancer cells. Coloured scanning electron micrograph (SEM) of cancer cells (orange) from a kidney tumour. Cancer cells divide rapidly in a chaotic manner and often clump to form tumours, which may invade and destroy surrounding tissues. These cells have extended many thread-like cytoplasmic projections from their surfaces. The most common form of kidney cancer is renal cell carcinoma. Symptoms include bloody urine, back pain and abdominal swelling. Treatment includes surgical removal of the affected tissues, which may be combined with chemotherapy (anti-cancer drugs). Magnification: x1300 at 6x7cm size.