Mesothelium is found in membranes lining the thoracic, abdominal and pericardial cavities.
Many body parts can be affected by mesothelioma. Mesothelioma may originate in the pleura, peritoneum, pericardium and genital tract. The pleura is the membrane in the thoracic cavity. The peritoneum is membrane which lines the abdominopelvic cavity. The pericardium is the membrane around the heart.
The most common site for mesothelioma to originate is the pluera. The pleura can be divided into visceral and parietal pleura.