Choriocarcinoma Presenting as a Pleural Effusion.

Choriocarcinoma is a germ cell tumor characterized by widespread metastases and poorly differentiated cells. Non-gestational choriocarcinoma, or primary choriocarcinoma is a trophoblastic disease which is associated with a poor patient prognosis and is markedly angioinvasive. Primary non-gestational mediastinal choriocarcinoma is a very rare disease and represents an aggressive malignancy, primarily seen in young males. Those with primary mediastinal choriocarcinoma have symptoms that are non-specific such as cough, dyspnea, hemoptysis, and chest pain. Here we present the case of a 47-year-old Caucasian female who presented with worsening dyspnea and cough. Laboratory testing revealed elevated alkaline phosphatase, human chorionic gonadotropin, and cancer antigen 125. Chest X-ray was significant for a large right pleural effusion and a computed tomography angiogram of the chest showed a soft tissue mass in the anterior medial right lung base/right middle lobe. Thoracentesis yielded results consistent with malignant cells favoring a germ cell tumor. Biopsy of the mediastinal mass revealed positivity for inhibin and both human chorionic gonadotropin and CD-10 which led to the diagnosis of primary choriocarcinoma. Primary mediastinal choriocarcinoma is uncommon and often has a non-specific clinical presentation. A high degree of suspicion is needed as this malignancy can be aggressive, necessitating urgent definitive tissue biopsy diagnosis to guide appropriate therapy.