Preoperative imaging of pulmonary metastases in patients with melanoma: implications for minimally invasive techniques.

Hypothesis: Preoperative imaging underestimates the number of pulmonary melanoma metastases. Although thoracoscopic resection is less invasive than resection via thoracotomy, it does not allow manual palpation of the lung to identify any metastases not visible on the preoperative scan or at the time of resection.

Design: Retrospective review of a prospectively maintained database.

Setting: Tertiary referral center.

Patients: A total of 170 patients who underwent preoperative computed tomography of the chest, followed within 30 days by thoracotomy for resection of pulmonary metastatic melanoma.

Main outcome measures: Number of pathology-confirmed pulmonary metastases detected by preoperative chest computed tomography vs intraoperative manual palpation.

Results: The mean age of the patients was 49.5 years at initial diagnosis of melanoma and 57.1 years at diagnosis of pulmonary metastases; 69% of patients were male. A total of 334 pulmonary metastases were resected; the mean lesion size was 2.0 cm (range, 0.1-14.0 cm). In 49 of 190 pulmonary resections (26%), manual palpation of the subpleural parenchyma revealed lesions not identified during preoperative imaging. The rate of 5-year overall survival was 33%.

Conclusions: Preoperative imaging underestimates the number of pulmonary lesions in patients with metastatic melanoma. Because incomplete resection of metastatic disease is associated with worse outcomes, we recommend caution when considering a minimally invasive approach for the resection of pulmonary metastatic melanoma.