Determining the Severity of Mesothelioma

Once the diagnosis of malignant mesothelioma has been confirmed, the next step is determining the extent of the disease (called staging). Imaging studies, such as computed tomography (CT) and magnetic resonance imaging (MRI), allow physicians to assess the stage of the disease and determine the most appropriate treatment. The stages of malignant mesothelioma are:

  • Stage I - The tumor is found in the pleura with or without some involvement of the lung, pericardium (lining of the heart) or diaphragm.
  • Stage II - The tumor is found in a stage I location, plus there is involvement of some ymph nodes in the chest.
  • Stage III - The tumor has extended into the chest wall, ribs or heart, through the diaphragm or into the peritoneum (the abdominal lining). There also may be involvement of the lymph nodes.
  • Stage IV - The tumor has spread through the bloodstream to distant sites (it has metastasized).
  • Recurrent Mesothelioma - The tumor has recurred after treatment.

Stage I also is called localized disease, whereas Stages II to IV are called advanced disease. Stage I disease generally has the best prognosis, particularly when the tumor is of the epithelial type.