Posterior mediastinal venous masses in patients with portal hypertension.

Of 304 consecutive splenic venograms performed for suspected portal hypertension, oesophageal collateral veins were filled in 145. In seven patients massively dilated paraoesophageal collaterals were visible on the plain chest radiograph as a retrocardiac posterior mediastinal mass. Erect and supine radiographs have been compared in four patients, and the Valsalva and Mueller manoeuvres performed in one patient. The size of the masses was unchanged by these procedures, which were therefore of no value in differential diagnosis. The mass was still present immediately after portocaval anastomosis in one patient, but in another is no longer seen on radiographs taken seven years postoperatively. All seven patients also had submucosal oesophageal varices and therefore the barium swallow remains the most useful study to clarify the nature of a retrocardiac mass. Correct identification of pseudotumoural venous collaterals may avoid unnecessary further investigation.