MESOTHELIOMA DIAGNOSIS

The diagnosis of malignant mesothelioma cancer begins with a medical history to document the patient's symptoms and any possible asbestos exposure, followed by a complete physical examination. These steps generally are followed by a chest or abdominal X-ray or an MRI, which allows the doctor to assess the size, location and extent of the tumor in the chest or abdomen.

If fluid is present in the pleura or peritoneum, a thin needle may be used to collect a small sample of the fluid for examination. This procedure, called fine-needle aspiration, also may be used to drain the fluid to relieve symptoms such as chest pain and shortness of breath that can result from an effusion. Occasionally, mesothelioma cancer can be diagnosed with this fluid sample alone, but usually a tissue sample (biopsy) is required. The tissue sample can be obtained via thoracoscopy (for a pleural tumor) or via laparoscopy (for an abdominal tumor). In both procedures, a tube-like instrument inserted through a small incision allows the physician to view the tumor and collect a tissue sample. Patients suspected of having malignant pleural mesothelioma also may need a procedure called bronchoscopy.

In all cases, a biopsy is needed to confirm a mesothelioma diagnosis. In a biopsy, a medical oncologist (a doctor who specializes in diagnosing and treating cancer) removes a sample of tissue for examination under a microscope by a pathologist. A biopsy may be done inusing different techiques, depending on where the abnormal area is located. If the cancer is in the chest, the doctor may perform a thoracoscopy. In this procedure, the doctor makes a small cut through the chest wall and puts a thin, lighted tube called a thoracoscope into the chest between two ribs. Thoracoscopy allows the doctor to look inside the chest and obtain tissue samples. If the cancer is in the abdomen, the doctor may perform a peritoneoscopy. To obtain tissue for examination, the doctor makes a small opening in the abdomen and inserts a special instrument called a peritoneoscope into the abdominal cavity. If these diagnostic procedures do not yield enough tissue, more extensive diagnostic surgery may be needed to confirm or rule out a mesothelioma diagnosis.

In the event of a definitive mesothelioma diagnosis, the doctor will want to learn the stage (or extent) of the disease. Determining the stage of the disease involves more tests in a careful attempt to find out whether the cancer has spread (metastasized) and, if so, to which parts of the body. Knowing the stage of the disease helps the doctor choose an appropriate plan of treatment.

A mesothelioma diagnosis is described as "localized" if the cancer is found only on the membrane surface where it originated. It is classified as advanced if it has spread beyond the original membrane surface to other parts of the body, such as the lymph nodes, lungs, chest wall, or abdominal organs.