Evaluation of tomography and mediastinoscopy for the detection of mediastinal lymph node metastases.

In a prospective study of 88 patients seen consecutively with proven or suspected bronchial carcinoma, the validity of x-ray tomography and routine mediastinoscopy was tested for the detection and evaluation of mediastinal lymph node metastases. Positive mediastinum was defined as malignant tissue found in the mediastinum and negative mediastinum as mediastinoscopy with negative results plus a negative intraoperative mediastinal lymph node dissection. Thirty-four patients were eliminated from the analysis because carcinoma was not found or because mediastinal evaluation was incomplete by these criteria. Twenty-eight of the remaining 54 patients had mediastinal metastases. Sensitivity was 67% for tomography and 79% for mediastinoscopy. Specificity was 92% for tomography and 100% for mediastinoscopy. The differences were not significant. Sixty-six of 85 mediastinoscopies were unnecessary or unhelpful in the decision to exclude a patient from surgical intervention. Among 19 patients with lesions presumed to be inoperable based on results of mediastinoscopy (i.e., perinodal metastatic growth suspected by palpation or histologically proven), 14 patients had positive tomographic scans and 1 could not be evaluated radiographically because of right upper lobe atelectasis. We conclude that tomography of the upper mediastinum should be used to select patients for mediastinoscopy.