This information can be important in evaluating a patient for potential pleurectomy or extrapleural pneumonectomy. Pleurectomy used as a palliative procedure may be performed where more extensive surgery is not an option. Laproscopy is used in mesothelioma patients in cases where imaging techniques suggest possible invasion of the tumor through the diaphragm. Mediastinoscopy is sometimes used as an aid in staging extent of disease when enlarged nodes are seen using imaging techniques. It involves placement of a catheter run under the skin from the pleural to the peritoneal cavity. It is also possible to gauge the extent of the tumor and make a determination of surgical resectability.