Anterior Mediastinal Germ Cell Tumor Presenting With Superior Vena Cava Obstruction and Malignant Pericardial Effusion.

Primary mediastinal germ cell tumors (PMGCTs) are rare extragonadal neoplasms that most commonly affect young men and may present with compressive cardiopulmonary complications due to their location in the anterior mediastinum. Superior vena cava obstruction and malignant pericardial effusion are serious manifestations that require prompt recognition and coordinated multidisciplinary management. We report a case of a 30-year-old male patient with a large anterior mediastinal germ cell tumor causing superior vena cava (SVC) obstruction and malignant pericardial effusion with impending cardiac tamponade. The patient underwent chemotherapy followed by successful surgical resection with SVC reconstruction using a polytetrafluoroethylene (PTFE) graft under cardiopulmonary bypass. This case underscores the diagnostic complexity of mediastinal germ cell tumors and highlights the importance of multidisciplinary care when these tumors invade or compress great vessels and adjacent cardiac structures.