Primary mediastinal yolk sac tumor treated with platinum-based chemotherapy and extended resection: Report of seven cases.

Background: Primary mediastinal yolk sac tumor, which is also known as endodermal sinus tumor, is a rare but lethal neoplasm, and it is a kind of mediastinal non-seminomatous germ cell tumor. The current standard treatment in mediastinal non-seminomatous germ cell tumors is chemotherapy combined with postchemotherapy residual mass resection. We report on seven cases of primary mediastinal yolk sac tumor treated with platinum-based chemotherapy and extended resection.
Methods: We experienced seven cases of primary mediastinal yolk sac tumor between August 2014 and August 2017. All cases had markedly raised α-fetoprotein and normal β-human chorion gonadotropin. Computed tomography scan revealed an anterior mediastinal tumor in all cases. Five patients underwent needle core biopsy, which showed a mediastinal yolk sac tumor. They received preoperative platinum-based chemotherapy and then underwent extended resection, and four of them received postoperative platinum-based chemotherapy. Two other patients did not receive preoperative biopsy, and they underwent surgical extended resection and then received postoperative platinum-based chemotherapy.
Results: Two patients (29%) experienced a postoperative complication, including one pneumonia and one atelectasis. There were no operative deaths. R0 resection was achieved in six patients (86%), and R2 resection was achieved in the other patient. Three patients experienced pulmonary metastases within one year, and two of them soon died. Four other patients were alive without recurrence at the time of writing.
Conclusion: Primary mediastinal yolk sac tumor is rare, and the prognosis is poor. A multimodality aggressive approach including adjuvant chemotherapy followed by surgical resection is the optimal treatment and may lead to long-term survival.
(© 2018 The Authors. Thoracic Cancer published by China Lung Oncology Group and John Wiley & Sons Australia, Ltd.)