Extragonadal nongestational choriocarcinoma involving the lung: a report of three cases.

Primary choriocarcinoma of the lung is an extremely rare tumour, with about 20 cases reported in the literature. The case records of 3 female patients with nongestational, extragonadal choriocarcinoma apparently arising in the lung are presented to illustrate its clinical spectrum, the utility of serum beta human chorionic gonadotropin, and responsiveness to chemotherapy. Most plausible origins of these malignancies and differential diagnosis are briefly discussed.