How is mesothelioma diagnosed?

Diagnosis is the process of determining the kind of disease that is present. An accurate diagnosis is important because it helps to determine the type of treatment that you will undergo.Doctors may use a number of procedures to aid in the diagnosis of mesothelioma. The most common of those procedures are listed here. Whether one or a combination of these tests are conducted in a given patient’s case will depend on factors unique to the patient. Some tests might first be conducted to determine whether a biopsy should be performed. A biopsy is usually necessary to confirm a diagnosis.

• CT scan
  This type of X-ray provides a very detailed picture of the size and location of the cancer. The images taken are compiled by a computer to create a more complete image of the disease. The procedure is also called a computerized axial tomography (CAT) scan.
• PET scan
  A procedure in which a small amount of radioactive glucose (sugar) is injected into a vein, and a scanner is used to make detailed, computerized pictures of areas inside the body where the glucose is used. Because cancer cells often use more glucose than normal cells, the pictures can be used to find cancer cells in the body.
• Thoracoscopy
  The diagnosis of pleural malignant mesothelioma may involve your doctor looking inside the chest cavity with an instrument called a thoracoscope. For this procedure, an incision is made through the chest wall and the thoracoscope is put into the chest between two ribs. This procedure is usually done in the hospital. Before the procedure, the patient is given a local anesthetic.
• Bronchoscopy
  A bronchoscopy involves an examination of the lungs and air passages. The doctor places a lighted tube down the patient’s throat and trachea into the lungs. This procedure is called a bronchoscopy, and the instrument used is called a bronchoscope.
• Thoracentesis
  Some patients develop fluid in their lungs. This is called a pleural effusion. A sample of this fluid can be taken out with a needle injected into the chest and tested for cancer cells. This procedure for draining fluid from the lungs may also be performed in an attempt to relieve pain.
• Mediastinoscopy
  This is a test which examines the mediastinum. This area is in the center of your chest, between your lungs, and contains the heart, blood vessels and lymph nodes. You’ll need a general anesthetic for this test and therefore will probably spend at least one night in the hospital.
• Needle Biopsy
  For this procedure, the doctor will use a thin needle to take samples of cells for examination under microscope. This test can be uncomfortable but may take only a few minutes. The doctor may use an X-ray, CT scan or fluoroscopy to guide the needle as it is inserted into the tumor.
• Fluoroscopy
  Fluoroscopy is a diagnostic procedure in which X-rays are passed through the body and then projected onto a screen, providing a continuous image of the body’s internal structures. Small pieces of the tissue are taken and then sent to a laboratory for analysis.
• Wedge Biopsy
  For this procedure, an incision is made through the skin, and a wedge of tissue or tumor is obtained and sent to a laboratory for analysis. The patient is under general anesthesia for this procedure. A wedge biopsy is often used when other biopsy methods have been unable to confirm a diagnosis.
• Cytology and Pathology
  Pathology is the study of a disease, which looks at specific cells and types of a disease process to determine the cause. Pathology tests are performed on samples of body fluid or tissue to determine the cell type (cytology) of a specific disease. The process of looking at these samples may include using microscopes, electron microscopes and special cell-staining techniques that identify specific types of cancer cells. Certain types of dyes or coloring are added to the patient’s biopsy samples. Depending on how the tissue responds to the dye, the doctor can make or confirm a diagnosis. In making the diagnosis, the more information the doctor has about the tumor, the better he or she can recommend appropriate treatment. Knowing the type of disease helps to make the treatment more specific.