Objectives: Our objective was to explore the pathologic components of residual masses after primary chemotherapy in patients with metastatic nonseminomatous germ cell tumors.
Methods: A multicenter retrospective study was conducted of 71 patients with thoracic residual masses (39 patients had bilateral lung metastasis) after first-line cisplatin-based chemotherapy for disseminated nonseminomatous germ cell tumors. Among the 71 patients, 52 also had a retroperitoneal lymph node dissection.
Results: Pathologic findings in postchemotherapy residual masses included complete necrosis, teratoma, and viable cancer in 31%, 55%, and 14% of patients, respectively. Discordant pathologic findings were evidenced between retroperitoneal lymph node and thoracic (lung or mediastinal lymph nodes) residual masses in 27% of patients. When a bilateral pulmonary resection was performed, only 2 (5%) of 39 patients had discordant histologic findings between the two lungs. Among patients who had necrosis only in residual masses from their first lung (n = 20), 19 (95%) also had necrosis only in contralateral lesions. A single patient had necrosis only in the first lung and some teratoma in the contralateral lung.
Conclusions: This report shows a high rate (95%) of pathologic concordance between the two lungs. Avoiding contralateral lung surgery could therefore be considered when complete necrosis is found in the first lung after induction chemotherapy for nonseminomatous germ cell tumor.