Chest or abdomen. Mesothelioma is usually detected along the inner lining of the lung (or pleural) cavities, of the heart sac (pericardium), or of the abdominal (or peritoneal) cavities.
The lungs. Mesothelioma is a malignancy of the covering of the lungs, called the pleura. It is usually discovered on a chest xray or a ct scan of the chest.