Background: Primary mediastinal seminomas (PMS) are rare tumors that are morphologically similar to their testicular counterparts but may have different biologic behavior due to their particular anatomical location.
Aim: New cases report of PMS CASES: Three new cases of primary mediastinal seminoma are presented. The patients were men aged of 16, 33 and 47 years. Their clinical symptoms included cough, dyspnea, chest pain and superior vena cava syndrome. None of the patients had a previous history of testicular neoplasm or tumor elsewhere. Mediastinoscopic biopsy was performed and histological examination results revealed a seminoma. Immunohistochemical showed membranous staining with placental alkaline phosphatase in the three cases. Chemotherapy has largely replaced surgical resection and radiotherapy as the initial treatment in patients with mediastinal seminoma.