Thymic Cyst Causing Superior Venacava Syndrome Relieved by Mediastinoscopy—A Rare Presentation

Superior venacava obstruction is most often caused by intrathoracic malignant masses. The commonest cause of benign superior venacava obstruction is fibrosing mediastinitis. A thymic cyst causing marked superior venacava obstruction is very rare and has not been reported. We hereby present a case of a 40-year-old man with such a finding who presented with chest pain and facial congestion. Evaluation revealed a mediastinal mass causing marked superior venacaval obstruction. He underwent a mediastinoscopy, which showed a cyst. It was drained following which there was complete resolution of symptoms post-operatively. Histopathology of the lesion confirmed a thymic cyst.