MALIGNANT PLEURAL EFFUSIONS AFTER RESECTION OF PULMONARY ADENOCARCINOMA

OBJECTIVE: To evaluate the clinicopathologic features of malignant ple ural effusions secondary to pulmonary adenocarcinoma in patients who h ave undergone surgical resection of the primary tumor. STUDY DESIGN: C linical, pathologic and cytologic material from 19 patients who develo ped malignant pleural effusions after resection of pulmonary adenocarc inoma was reviewed. RESULTS: Malignant effusions developed only in pa patients with either lymph node or pleural involvement by neoplasm. Ti me to development of the effusion after resection and overall survival correlated with histologic findings. Malignant effusions in patients who survived >24 months were secondary to another primary tumor (eithe r breast or a new pulmonary carcinoma). Malignant effusions developed significantly sooner alter resection (mean 5.0+/-2.0 months, median 5) in patients with lymph nodal metastases than in those with pleural in volvement by neoplasm (mean 11.2 +/- 2.5 months, median 12) (Student's t test P=.01, Mann-Whitney U test .04). Nevertheless, survival after resection for patients with lymph node involvement (mean 9.0 +/- 3.6 m onths, median 8) and those with pleural involvement (mean 12.3 +/- 2.5 months, median 12) was not significantly different. CONCLUSION: Malig nant effusions developing in patients more than two years following re section of a pulmonary adenocarcinoma are likely to be secondary to an other primary neoplasm. Lymph node and pleural involvement at the time of resection are risk factors for the development of a malignant effu sion. Patients with lymph Mode involvement develop malignant effusions sooner than those with pleural involvement, but the overall survival is not significantly different.