Neck mass caused by thrombus in the external jugular vein.

Three cases of lateral neck tumors caused by thrombosis of the external jugular vein have been presented. Microscopic examination of the excised thrombosed veins revealed all of them to have a dilated architecture with somewhat degenerated vessel walls much like an aneurysm. Such a dilatation would cause some stasis and eddy currents and make the vessels more susceptible to thrombus formation. The final factor which induced these thrombi remains unknown. Indeed, when the interrelation of the factors discussed previously is considered, multiple etiologic factors appear most likely. Some form of minor trauma, although not documented, would still seem the most likely cause of thrombosis of a vein in a patient with no previous symptoms. In case III, trauma of inflammatory changes in a mass already noted to be present for some time could have induced thrombosis within the dilated vessel. Thrombosis of the external jugular vein is yet another lesion in the extensive differential diagnosis of a mass in the lateral neck.