Giant intrathoracic tumor masquerading as an enlarged cardiac silhouette

This report describes a relatively asymptomatic 52-year-old man who had a markedly enlarged cardiac silhouette on chest roentgenogram when first seen. Clinical studies confirmed the presence of a mass, and thoracotomy revealed a huge intrathoracic tumor. The lesion was interpreted as an intrapulmonary hamartoma that had undergone malignant degeneration.