Intracaval and intracardiac extension of malignant thymoma.

A case of malignant thymoma presenting as the superior vena cava syndrome is reported. A 56-year old male was admitted with superior vena cava syndrome. CT and NMR-CT scan showed a solid homogenous superior mediastinal mass; which filled the lumen of the superior vena cava and the right atrium. A biopsy of the right atrial mass showed myxoma, and operation was performed. Histopathologically the tumor was diagnosed as thymoma. Intracaval and intracardiac extension of a thymoma is very rare.