Cells in the lungs are constantly multiplying and being replaced to ensure the lungs stay clean and healthy. Sometimes the lungs produce cells too rapidly causing a cellular mass known as a tumour. When this tumour is restricted to a few layers of cells it is known as benign. If the tumour spreads to surrounding tissues or to other organs it is known as malignant or cancerous. In the lung cancer photo below the right lung is healthy, while the left lung is pale in colour and hard to the touch indicating the presence of lung tumours.
Lung cancer photo courtesy of www.upstate.edu
Lung cancer is thought to develop over some time with pre cancerous cells being present before symptoms arise or any abnormalities are visible on an x-ray. Below is an x-ray of healthy lungs.
Image courtesy of www.texascollaborative.org
Once the cells multiply they develop blood vessels which feed the tumours creating cancerous cellular masses. Below is an x-ray of a tumour:
Image courtesy of www.scienticphysician.com
There are two main types of lung cancer which have been named for the way the cells appear under a microscope. The most common form of lung cancer is non-small cell lung cancer accounting for about 80% of all lung cancer. There are 3 main types of NSCLC and smoking can be a contributor to all of these. Small cell lung cancer makes up about 20% of lung cancer and is almost always caused by smoking. Only 1% of SCLC is not caused by smoking. SCLC is the most aggressive and rapidly growing of all lung cancers and has a very high mortality rate. This type of lung cancer can spread rapidly throughout the body and is often discovered once the disease is widespread. Once the disease has reached this level the survival rate is between 0% and 2%.
December 23rd, 2008 at 8:19 pm
That was disgusting!! OMG!! I’m never going to smoke and if you do stop immediatly!!
December 29th, 2008 at 8:59 am
this was rediculas ,why do people smoke OMG!!!!!I am never going to smoke