THORACOTOMY IN THE MANAGEMENT OF GESTATIONAL CHORIOCARCINOMA - A CLINICOPATHOLOGICAL STUDY

Background. Pulmonary metastases occur frequently in patients with ges tational choriocarcinoma and most of these patients achieve remission with chemotherapy alone. Thus, the indications for surgical interventi on are limited, but in appropriately selected patients, resection of a chemotherapy-resistant lung lesion can be curative. Methods. Nine pat ients with choriocarcinoma metastatic to the lung underwent 11 thoraco tomies. The procedure was done in two patients for diagnosis and in se ven to remove a resistant focus of tumor in the lung. The excised resi stant tumors in six patients were studied histopathologically, immunoh istochemically, 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 d isease. The residual lung nodules in these patients with chemotherapy- resistant tumors were characterized by the presence of large mononucle ated tumor cells that showed features intermediate between those of cy totrophoblasts and syncytiotrophoblasts but lacking ultrastructural an d immunohistochemical features of the intermediate trophoblasts seen i n placental site tumors. Conclusions. A major role for operative treat ment of chemotherapy-resistant choriocarcinoma in the lung is suggeste d by the observation that some of the resistant tumors contain a uniqu e variant of trophoblastic cells that show a decreased sensitivity to chemotherapy but are amenable to surgical resection.