Endoscopic Ultrasound-Guided Fine Needle Aspiration for Staging of Malignant Pleural Mesothelioma

Abstract

Radical surgery for malignant pleural mesothelioma does not improve survival in patients with nodal metastases. Imaging is poor at predicting nodal involvement and mediastinoscopy, though frequently used, is of low sensitivity. As endobronchial ultrasound (EBUS) and esophageal endoscopic ultrasound (EUS) are accurate for nodal staging of lung cancer, we hypothesized that they would be at least as sensitive as cervical video-mediastinoscopy for nodal staging of mesothelioma. Eighty-five patients with mesothelioma who were potential candidates for radical surgery underwent preoperative staging with mediastinoscopy (n = 50) or EBUS (n = 38). Eleven patients also underwent EUS. Diagnostic yield (specimens containing lymphocytes or tumor cells) was 100% for mediastinoscopy and 84% for EBUS (p < 0.001). Mediastinoscopy identified 7 of 50 (14%) patients with nodal metastases. Thirty-eight (76%) mediastinoscopy-negative patients underwent surgery with nodal sampling and there were 18 false negatives. Endobronchial ultrasound identified 13 of 38 (34%) patients with nodal metastases. Twenty-two (58%) EBUS-negative patients underwent surgery with nodal sampling and there were 10 false negatives. Sensitivity and negative predictive value for mediastinoscopy were 28% and 49%, and 59% and 57% for EBUS. Eleven patients had EUS preoperatively, which revealed infradiaphragmatic nodal metastases in 5 patients. Although this study is retrospective, EBUS had higher sensitivity than either mediastinoscopy or imaging studies for detection of nodal metastases. Nevertheless, the ability to accurately identify nodal involvement preoperatively in patients with mesothelioma remains suboptimal. Esophageal ultrasound may complement EBUS particularly in cases where infradiaphragmatic nodal metastases are suspected.