Continued from part 1. If the effusion is suspicious for some infection or cancer, sample of the fluid may give the clue whether the cause is benign or malignant. However, four out of five tests may miss the cancer. Eventually, the biopsy of the pleura by a needle or by a surgical procedure confirms the diagnosis of the mesothelioma. For abdominal mesothelioma, an abdominal x-ray checks the fluid in your belly. Sometime an x-ray may show not only effusions, but also mass, or signs of asbestos accumulation, pleural plaques and calcifications or scarring due to asbestosis and chronic inflammation. Drain of the fluid is done by needle in the chest or abdominal cavity. The name is thoracocentesis or pleural aspiration from chest, and abdoparacentesis or peritoneal aspiration in tummy. At modern days the CT (computerized tomography) scan is used more often. CT is a special x-ray machine that shows sliced images of your body. CT scan of chest or abdomen shows the swellings in organs, cavities, and lymph nodes. A contrast dye may help to the scan. CT scans show pleural effusion, pleural thickening, pleural calcification, spreading of tumor into chest wall. However, CT do not really distinguish benign asbestos disease, lung cancer or mesothelioma. Doctors also use CT scans for guiding needle aspiration of suspicious pleural masses. Thoracoscopy is the procedure when a surgeon makes small cut in your chest wall between two ribs and looks through a thoracoscope (a tool with a video camera). The biopsy (tissue sample) goes to a lab to check for cancer cells. Bronchoscopy allows doctors to look inside the airways. A thin flexible tube (bronchoscope) helps to get samples of tissue and send them sent to a lab for testing for cancer cells. Mediastinoscopy checks mediastinum (the area in chest containing heart, great blood vessels, lymph nodes, esophagus, nerves and so on). Mediastinoscopy allows sampling lymph nodes in your body to look for metastases. Laparoscopy is a surgical procedure when doctors look inside of your belly with a small camera-fitted tube. The surgeons will biopsy suspicious areas. The bioptate (the tissue sample) goes to the laboratory. A pathologist checks it under a microscope. Laparoscopy leaves a small cut on the skin of your belly. Another name of the same procedure is peritoneoscopy. The tool is named peritoneoscope. Putting a needle into your abdomen and removing the fluid inside is named paracentesis Putting a needle into your chest and draining the fluid is named thoracentesis. MRI (magnetic resonance imaging) scan gives a sliced picture of the inside of your body. It is better than X-ray or CT scan because there is no radiation of your body. However it requires significant time. Sometimes it takes up to 20 minutes. And some people afraid to stay in the machine for half an hour required for the test. Besides MRI has a limitation. The test requires avoiding metals in your bodies (like metal joints and other metal implants). MRI is not a routine test, so sometime it is not ordered. Magnetic Resonance Imaging is most commonly ordered to determine the extent of tumor to plan the surgery. MRI also easier than CT scans shows enlarged lymph nodes and surface of diaphragm and this is important for surgical planning. Positron Emission Tomography (PET) came recently for diagnosing different type of cancers and mesothelioma as well. PET uses special radioactive substances that emit positrons. Localized mesothelioma is confined to the pleura. Advanced mesothelioma spreads to the lungs, chest wall, abdomen and lymph nodes. Pathological examination checks biopsy samples under the microscope It is difficulty to diagnose mesothelioma sometime. The cells of the tumor may be of many different types. These cells may look similar to other cancers. Peritoneal cells may look similar to pleural mesothelioma or other types of lung cancer and even ovarian cancer. Epithelioid type of mesothelioma is more common and considered better for treatment more than aggressive sarcomatous type. Biphasic mesothelioma is the mixture of both. Doctors and scientists also proposed some immunological makers to find mesothelioma, however majority of the markers are not very specific. Just to mention: Epithelial membrane antigen, CEA (carcinoembryonic antigen very unspecific, may happen in many different cancers), Calretinin, Mesothelin, Cytokeratin, osteopontin and some others. Look also: http://cis.nci.nih.gov/fact, http://www.nlm.nih.gov, http://www.rdoctor.com So, to recap, the tests used by doctors: *X-rays *CT scan *Thoracocentesis *Paracentesis *Thoracoscopy *Bronchoscopy *MRI scan *Mediastinoscopy *Laparoscopy *All kinds of biopsy The diagnosis is done after careful evaluation of complaints, physical exam and imaging in addition to the biopsy. Keywords: Diagnosis, asbestos cancer, malignant pleural mesothelioma, mesothelioma symptoms, peritoneal mesothelioma, lung cancer |
