Extended surgical staging for potentially resectable malignant pleural mesothelioma

Background. Extrapleural pneumonectomy for malignant pleural mesothelioma (MPM) is a high-risk procedure, and patients require careful preoperative staging to exclude advanced disease. Computed tomography, magnetic resonance imaging, and positron emission tomography are useful staging modalities, but do not reliably identify contralateral mediastinal involvement or transdiaphragmatic invasion. We evaluated the role of extended surgical staging procedures, which generally includes a combination of laparoscopy, peritoneal lavage, and mediastinoscopy, to more precisely stage patients with MPM. Methods. One hundred eighteen patients with MPM, deemed clinically and radiologically resectable, underwent extended surgical staging. Mediastinoscopy was performed in 111 patients, laparoscopy in 109 patients, and peritoneal lavage in 78 patients. Results. Ten (9.2%) patients had gross evidence of transdiaphragmatic or peritoneal involvement. Peritoneal lavage was positive for metastatic MPM in 2 (2.6%) patients, neither of whom had obvious transdiaphragmatic invasion. Ipsilateral mediastinal nodes contained metastatic tumor in 10 of 62 (16.1%) patients. Contralateral nodes were positive in 4 of 111 (3.6%) patients. Of the patients who underwent biopsy of both ipsilateral and contralateral mediastinal nodes, and who had complete pathologic staging after extrapleural pneumonectomy (n = 46), 14 (30.4%) had N2-positive nodes. Only 5 of these patients were correctly identified by mediastinoscopy (sensitivity 36%, accuracy 80%). Extended surgical staging identified 16 (13.6%) patients who had contralateral nodal involvement, transdiaphragmatic invasion, or positive peritoneal cytology. Conclusions. Extended surgical staging defines an important subset of patients with unresectable MPM not identified by imaging. Because of the potential morbidity associated with extrapleural pneumonectomy, we advocate that extended surgical staging be performed in all patients with MPM before resection.