Tests and diagnosis

If you have signs and symptoms that might indicate mesothelioma, your doctor will conduct a physical exam to check for any lumps or other unusual signs. Your doctor may order imaging scans, such as a chest X-ray and a computerized tomography (CT) scan of your chest or abdomen, to look for abnormalities. Based on the findings, you may undergo further testing to determine whether mesothelioma or another disease is causing your signs and symptoms.

Biopsy
Biopsy, a procedure to remove a small portion of tissue for laboratory examination, is the only way to determine whether you have mesothelioma. Depending on what area of your body is affected, your doctor selects the right biopsy procedure for you. Options include:

• Fine-needle aspiration. The doctor removes fluid or a piece of tissue with a small needle inserted into your chest or abdomen.
• Thoracoscopy. Thoracoscopy allows the surgeon to see inside your chest. In this procedure, the surgeon makes one or more small incisions between your ribs. A tube with a tiny video camera is then inserted into your chest cavity — a procedure sometimes called video-assisted thoracoscopic surgery (VATS). Special surgical tools allow your surgeon to cut away small pieces of tissue for testing.
• Laparoscopy. Laparoscopy allows the surgeon to see inside your abdomen. Using one or more small incisions into your abdomen, the surgeon inserts a tiny camera and special surgical tools to obtain a small piece of tissue for examination.
• Thoracotomy. Thoracotomy is surgery to open your chest between the ribs to allow a surgeon to check for signs of disease. A sample of tissue may be removed for testing.
• Laparotomy. Laparotomy is surgery to open your abdomen to allow a surgeon to check for signs of disease. A sample of tissue may be removed for testing.

The tissue sample is analyzed under a microscope to see whether the abnormal tissue is mesothelioma and what types of cells are involved. The type of mesothelioma you have determines your treatment plan.

Staging
Once mesothelioma is diagnosed, your doctor orders other tests to determine the extent, or stage, of the cancer. Imaging tests that may help determine the stage of your cancer may include:

• Chest X-ray
• CT scans of the chest and abdomen
• Magnetic resonance imaging (MRI)
• Positron emission tomography (PET)

Your doctor determines which tests are more appropriate for you. Not every person needs every test.

Once the extent of pleural mesothelioma is determined, a stage is assigned.

• Stage I mesothelioma is considered localized cancer, meaning it's limited to one portion of the lining of the chest.
• Stage II mesothelioma may have spread beyond the lining of the chest to the diaphragm or to a lung.
• Stage III mesothelioma may have spread to other structures within the chest and may involve nearby lymph nodes.
• Stage IV mesothelioma is an advanced cancer that has spread more extensively within the chest. Stage IV may also indicate that mesothelioma has spread to distant areas of the body, such as the brain, liver and lymph nodes elsewhere in the chest.

Formal stages aren't available for other types of mesothelioma because these types are rare and aren't well studied.

Source:http://www.mayoclinic.com/health/mesothelioma/DS00779/DSECTION=tests-and-diagnosis