Non-Seminomatous Germ Cell Tumor Presenting with Superior Vena Cava Syndrome

Primary mediastinal yolk sac tumor: A case report and literature review

Key Clinical Message

There are limited published cases of primary mediastinal yolk sac tumor (PMYST), with no consensus on the best treatment alternative. By far, the surgery oriented comprehensive therapies are the main treatment methods. The surgical strategy should be individualized and aimed at radical resection, considering all the possibilities, including the use of cardiopulmonary bypass and prosthetic materials.

Abstract

A 15-year-old boy was diagnosed as PMYST. The tumor, with a size about 13 × 12 × 8 cm, was located in the right upper mediastinum, closely adhering to ascending aorta, superior vena cava, right atrium, and the right hilum. After 6 cycles chemotherapy of bleomycin, etoposide, and cisplatin (BEP), no significant change was found in the size of tumor. Subsequently, an extended tumor excision including partial resection of the right lung, the pericardium, the diaphragm and the right phrenic nerve, was performed successfully with cardiopulmonary bypass on standby. During 6 months of follow-up, there was no tumor recurrence. Meanwhile, in PubMed, we searched the English case reports and case series of PMYST during the past decade. A total of 73 articles were retrieved, in which 22 articles on the therapy and prognosis of PMYST were extracted and reviewed, included 16 case reports and 6 case series with a total of 52 patients. Due to the rarity of PMYST, it is difficult to provide a specific treatment regimen. The surgery-oriented comprehensive therapies are still the main treatment methods. The surgical strategy should be individualized and aim at radical resection, considering all the possibilities, including the use of cardiopulmonary bypass and prosthetic materials.

Primary mediastinal yolk sac tumor: a case report and literature review

Primary mediastinal yolk sac tumors (YSTs) are rare and have a high degree of malignancy. This article reports a 42-year-old man with a primary mediastinal YST. The patient presented with chest tightness and shortness of breath. Using a contrast-enhanced computer tomography (CT) scan, the mediastinal space was found to be occupied by a mass shadow, about 10 cm × 8 cm with a clear boundary and low density. Serum alpha-fetoprotein (AFP) was elevated to 7169.66 ng/ml. The 5th day after hospitalization, a percutaneous biopsy of the mediastinal mass was performed. Malignant tumor cells were found by cytologic examination. According to the pathological morphology and immunohistochemical results, the tumor was diagnosed as primary mediastinal YST. Subsequently, the patient underwent five cycles of adjuvant chemotherapy including bleomycin, etoposide, and cisplatin (BEP) and surgical tumor removal. One month after operation, AFP was elevated to 252.96 ng/ml. CT examination showed that the tumor recurred. As of September 12, 2020, the patient has undergone four cycles of VIP (etoposide, ifosfamide, cisplatin) chemotherapy after relapse, and the patient's condition is currently in partial remission.

[Diagnosis and treatment of seven primary mediastinal yolk sac tumors]

OBJECTIVE

Primary mediastinal yolk sac tumor, which is also known as endodermal sinus tumor, is a rare but lethal neoplasm and its prognosis is very dismal. The current treatment for this tumor is controversial, and chemotherapy combined with resection of residual lesions is adopted sometimes. We summarized the experience of seven primary mediastinal yolk sac tumors treated with platinum-based chemotherapy and extended resection in Peking University First Hospital.

METHODS

Clinicopathological data of the patients with primary mediastinal yolk sac tumor who received operation in Peking University First Hospital between August 2014 and August 2018 were collected and analyzed retrospectively.

RESULTS

We experienced seven primary mediastinal yolk sac tumors during this period. Computed tomography scan revealed an anterior mediastinal tumor in all the patients and all of them had markedly raised alphafetoprotein (AFP) and normal β-human chorion gonadotropin (β-HCG). Five patients underwent needle core biopsy before treatment, which showed a mediastinal yolk sac tumor. All of these patients received preoperative platinum-based chemotherapy and they all presented partial response according to computed tomography. Two other patients did not receive preoperative biopsy, so they directly underwent extended resection. All of the seven patients underwent operation successfully and two of them experienced postoperative complications, including one with pneumonia and the other with atelectasis. R0 resection was achieved in six patients and R1 resection was achieved in the other patient. According to postoperative pathology, there were one microcyst subtype, one adenoid subtye, one giant capsule subtype and two hybrid subtypes. Surprisingly, there were no yolk sac tumor tissue in the other two patients after preoperative chemotherapy. All the patients received postoperative chemotherapy, excluded one patient who was unable to tolerate chemotherapy after operation. Three patients experienced postoperative pulmonary metastases within one year and two of them died soon. The other patient received chemotherapy and immunotherapy after recurrence and he was alive at the time of writing. Four other patients were alive without recurrence and metastasis.

CONCLUSION

Primary mediastinal yolk sac tumor is rare and its prognosis is poor. A multimodality approach including adjuvant chemotherapy and resection of residual lesions is the optimal treatment and it may lead to long-term survival.

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.