Carinal Compression from Primary Mediastinal Germ Cell Tumor.

Mediastinal masses can present as a medical emergency when there is central airway obstruction, superior vena cava (SVC) syndrome, direct mediastinal extension of tumor, or obstruction of the central pulmonary vasculature. Diagnostic evaluation may include the need for invasive tissue biopsy under anesthesia, which can pose several distinct risks for patients. Among the many etiologies of mediastinal tumors, primary mediastinal germ cell tumors are a rare form with a favorable prognosis.