Indications for mediastinal lymph node evaluation.

Successful surgical therapy for bronchogenic carcinoma depends upon an accurate lymph node assessment. Criteria were developed and reported to identify patients who would benefit from mediastinoscopy prior to thoracotomy. This report summarizes the prospective use of the criteria between 1974 and 1977 and the total experience from 1970 to 1977. Selection of patients for prethoracotomy mediastinal evaluation is primarily based on chest roentgenogram and cell type. Left upper lobe lesions meeting the criteria were submitted to mediastinotomy if mediastinoscopy was negative. Eighty-seven potentially resectable lesions were evaluated prospectively, and the total experience included 202 patients. Mediastinal metastasis occurred in 39 patients of the current and 82 patients of the total series. When metastases to the mediastinum were documented, roentgenographic evidence of metastasis was seen in 20 of 39 (51 percent) of the current and 44 of 82 (54 percent) of the total series. There was roentgenographic evidence of metastasis in central lesions, peripheral masses, and small peripheral lesions with mediastinal metastases in 50 percent, 25 percent, and 78 percent of the cases, respectively. Mediastinal metastases were reported 80 percent of the time before thoracotomy using these criteria. The use of mediastinotomy on left upper lobe lesions identified six of seven of the unresectable cases missed by the mediastinoscopy. The criteria will identify patients at high risk for mediastinal metastases who benefit from prethoracotomy surgical evaluation.