Primary Anterior Medistinal Choriocarcinoma in Male with Lung Metastasis and Pituitary Microadenoma: A Case Report

The authors report a case of a 29-year-old male presented with bilateral breast enlargement with no significant past medical history or estrogen exposure. Serum β-human chorionic gonadotropin (HCG) was 14,306.60 mIU and positron emission tomography-computed tomography discovered a malignant mass on the right side of anterior superior mediastinum. Magnetic resonance imaging demonstrated pituitary microadenoma. Pathological biopsy showed poorly differential pituitary adenoma and immunohistochemical staining displayed that CK(+), PLAP(−), AFP(−), HCG(+), CD30(−), Oct3/4(−), CK7(+), TTF-1(−), CD117(−), Ki 67(80+), CK5/6(−), EMA(partial+), inhibin(partial+). A diagnosis of primary anterior mediastinal choriocarcinoma metastasis to bilateral lungs accompanied with pituitary microadenoma was confirmed. Then the patient received chemotherapy combined with immunotherapy. But serum β-HCG level was still above the normal, and unfortunately, the patient died 6 months after his diagnosis. This case inspires us to think of the possibility of choriocarcinoma when a man presents gynecomastia or lung metastatic symptoms, adding Opdivo to the chemotherapy might not improve the poor treatment outcomes.