Primary pulmonary choriocarcinoma presenting with a hemothorax.

Primary pulmonary choriocarcinoma is an extremely rare condition that is difficult to diagnose. In this report, we describe a case of primary pulmonary choriocarcinoma that presented with a hemothorax, initially diagnosed as an ectopic pregnancy. The patient was treated successfully with surgery followed by combination chemotherapy. In rare instances such as this, choriocarcinoma can originate in sites outside the genital tract; a thorough and thoughtful evaluation will ensure an accurate diagnosis and prompt treatment.