Thoracotomy in the management of gestational choriocarcinoma. A clinicopathologic study.

BACKGROUND: Pulmonary metastases occur frequently in patients with gestational choriocarcinoma and most of these patients achieve remission with chemotherapy alone. Thus, the indications for surgical intervention are limited, but in appropriately selected patients, resection of a chemotherapy-resistant lung lesion can be curative.

METHODS: Nine patients with choriocarcinoma metastatic to the lung underwent 11 thoracotomies. The procedure was done in two patients for diagnosis and in seven to remove a resistant focus of tumor in the lung. The excised resistant tumors in six patients were studied histopathologically, immunohistochemically, and by electron microscopic examination (one patient).

RESULTS: Six (66.6%) patients achieved complete remission for periods ranging from 3 months to 18 years, and three patients died of their disease. The residual lung nodules in these patients with chemotherapy-resistant tumors were characterized by the presence of large mononucleated tumor cells that showed features intermediate between those of cytotrophoblasts and syncytiotrophoblasts but lacking ultrastructural and immunohistochemical features of the intermediate trophoblasts seen in placental site tumors.

CONCLUSION: A major role for operative treatment of chemotherapy-resistant choriocarcinoma in the lung is suggested by the observation that some of the resistant tumors contain a unique variant of trophoblastic cells that show a decreased sensitivity to chemotherapy but are amenable to surgical resection.