Benign obstruction of the superior vena cava.

Hunter' was the first to report a case of superior vena cava obstruction. Ehlrich2 et al. and McIntire and Sykes3 have extensively reviewed the world literature. Obstruction of the superior vena cava due to primary endothoracic malignant tumours or aneurysm is not uncommon, accounting for 94 per cent. of our cases, but benign lesions causing obstruction of this vessel are rare Oschner and Dixon4 collected I20 cases of thrombosis of the superior vena cava from the world literature. From the available data they concluded that 44 were due to phlebitis, 35 from external compression, 28 resulted from mediastinitis and in I3 cases the cause was either unstated or unknown. Of the 44 cases of phlebitis and associated thrombosis, only io could be termed as idiopathic. In the remaining the underlying aetiological agent named in order of frequency was syphilis, cardiac disease, pyogenic infections, tuberculosis and trauma. Thrombo-phlebitis arising in the main veins of the upper extremities may spread to involve the superior vena cava. Obstruction of the superior vena cava due to chronic mediastinitis was described by Hallet5 and of the 28 cases in the Oschner and Dixon4 series i i were due to syphilis, io to tuberculosis, one to pyaeogenic infection, one to trauma and five to unknown aetiology. Erganin and Wade6 reported three cases due to non-specific chronic fibrosing mediastinitis and Tubbs7 reported three cases due to chronic mediastinitis; in two of his cases the underlying cause could not be discovered. Benign tumours seldom cause superior vena cava obstruction. McArt et al.8 have reported a case of superior vena cava syndrome produced by retrosternal goitre, while McIntire and Sykes3 could find only two cases of benign tumours in the world literature. Pericardial bands and adhesions have also been mentioned as sole cause of superior vena cava obstruction. Gray and Skinner' have reported two cases of thrombosis ... .. ......i..