Giant Intracardiac Smooth-Muscle Cell Tumor Presenting as Superior Vena Cava Syndrome.

We report the case of a 53-year-old man presenting with a superior vena cava syndrome secondary to a giant intracardiac mass occupying the majority of the right-side cavities of the heart. A mass measuring 10.5 × 9.5 × 4.0 cm originating from the superior vena cava and occupying most of the right atrium extended through the tricuspid valve into the right ventricle. The mass was resected. The patient was discharged on postoperative day 11. The pathology report revealed the mass to be a smooth-muscle cell tumor of unknown malignant potential.