Stephen Hawking: 'There is no heaven; it's a fairy story'. In an exclusive interview with the Guardian, the cosmologist shares his thoughts on death, M-theory, human purpose and our chance existence. , science correspondent. Sunday 15 May 2011 17.00 EDT First published on Sunday 15 May 2011 17.00 EDT.
Both the growth of a tumor and the repair of a scrape on the knee are similar because they involve a mass amount of blood cells in a particular area. A growth of a tumor is a huge mass of cells that form together an cause it. And like the forming tumor, when you get a scrape on your knee blood cells are clumped together forming a large mass of blood also. They are different because there isn't an opening to a tumor allowing blood cells to flow out. When there is a scrape on your knee, there is an opening/cut, allowing blood cells to flow out properly.
Large growths can be aspirated, or drained with a needle. In some cases, a knee cyst will burst on its own, causing bruising, swelling, and pain. Though this is unpleasant, it usually doesn't require any treatment aside from painkillers, as the body will absorb the fluids in a matter of weeks.