A Rare Case of Mature Teratoma of the Mediastinum With Sarcomatous Components

Abstract

Teratoma of the anterior mediastinum is the most common extragonadal germ cell tumor in adults. Infrequently a malignant nongerm cell component is present. We report a case of teratoma with angiosarcoma and malignant glioma components. The patient is a 34-year-old man who presented with right-sided chest pain and shortness of breath. A chest X-ray showed a right anterior mediastinal mass which measured 11x15cm on computerized tomography. The alpha-fetoprotein was elevated at 128 ng/mL. A biopsy was performed and showed papillary vascular proliferation with cytological atypia. The patient received 1 cycle of vinblastine, ifosfamide, and cisplatin (VIP) chemotherapy. The mediastinal mass was refractory to chemotherapy and increased in size and subsequently excised. At gross dissection, the mass measured 19.4 × 14.1 × 9.6 cm and weighed 1.4 kg. Cut sections showed an encapsulated lesion with hemorrhage, focal calcifications, and multiple cysts with necrosis and hemorrhage. Microscopy showed extensive necrosis and mature teratoma admixed with well-differentiated angiosarcoma and a malignant glioma component. The angiosarcoma showed irregular anastomosing vascular channels lined by atypical endothelial cells with occasional mitoses and focal spindle cell proliferation. The vascular channels were positive for CD34 and CD31. The malignant glioma showed marked nuclear pleomorphism, increased mitosis and high proliferation index. Mature teratoma with nongerminal malignant tumor is a rare entity. The lesions occur in the anterior mediastinum and are more common in men. The malignant component may be a carcinoma or a sarcoma including embryonal rhabdomyosarcoma, angiosarcoma, and leiomyosarcoma. The sarcoma can exist in a pure form or in combination and arises in the primary tumor, recurrence or metastasis. There is poor response to conventional germ cell tumor chemotherapy. Mediastinal teratoma with a sarcomatous component is an aggressive disease and further investigation is needed to elucidate the lesions origins and behavior.