Mesothelioma, more precisely malignant mesothelioma, is a rare form of cancer that develops from the protective lining that covers many of the body’s internal organs, the mesothelium. It is usually caused by exposure to asbestos. Its most common site is the pleura (outer lining of the lungs and internal chest wall), but it may also occur in the peritoneum (the lining of the abdominal cavity), the pericardium (a sac that surrounds the heart), or the tunica vaginalis (a sac that surrounds the testis).
Most people who develop mesothelioma have worked on jobs where they inhaled asbestos and glass particles, or they have been exposed to asbestos dust and fiber in other ways. It has also been suggested that washing the clothes of a family member who worked with asbestos or glass can put a person at risk for developing mesothelioma. Unlike lung cancer, there is no association between mesothelioma and smoking, but smoking greatly increases the risk of other asbestos-induced cancers. Those who have been exposed to asbestos often utilize attorneys to collect damages for asbestos-related disease, including mesothelioma. Compensation via asbestos funds or lawsuits is an important issue in mesothelioma (see asbestos and the law).
CXR demonstrating a mesothelioma
The X-ray may reveal pleural thickening commonly seen after asbestos exposure and increases suspicion of mesothelioma. A CT (or CAT) scan or an MRI is usually performed. If a large amount of fluid is present, abnormal cells may be detected by cytopathology if this fluid is aspirated with a syringe. For pleural fluid, this is done by thoracentesis or tube thoracostomy (chest tube); for ascites, with paracentesis or ascitic drain; and for pericardial[disambiguation needed] effusion with pericardiocentesis. While absence of malignant cells on cytology does not completely exclude mesothelioma, it makes it much more unlikely, especially if an alternative diagnosis can be made (e.g. tuberculosis, heart failure). Unfortunately, the diagnosis of malignant mesothelioma by cytology alone is difficult, even with expert pathologists.
CT scan of a patient with mesothelioma, coronal section (the section follows the plane that divides the body in a front and a back half). The mesothelioma is indicated by yellow arrows, the central pleural effusion (fluid collection) is marked with a yellow star. Red numbers: (1) right lung, (2) spine, (3) left lung, (4) ribs, (5) descending part of the aorta, (6) spleen, (7) left kidney, (8) right kidney, (9) liver.