What are the pleura?
In pleural mesothelioma the initial site of disease is most often the pleura, an important thin membrane that lines the inside of the chest wall (parietal pleura), or the visceral pleura, which lines the lungs. The pleura is a sheetlike lining formed by rectangular cells called mesothelial cells, and is usually not more than a few layers thick. If unaffected by disease, it is comparable in thickness to that of a blown-up balloon membrane. There are two pleuras in the chest. The parietal pleura lines the inside of the chest wall like wallpaper, covering not only the inside of the ribs but also the diaphragm and pericardium.
