The detection of mediastinal parathyroid glands by computed tomography, selective arteriography, and venous sampling: an analysis of 17 cases.

Computed tomography (CT) scans were reviewed in 19 cases of proved mediastinal parathyroid glands. Glands were detected in five of 17 cases (29%) with adequate scans; four of six (67%) anterior mediastinal glands larger than 2 cm were visible. The smallest lesion demonstrated by CT ws 1.6 cm. In the same series, selective arteriography was positive in 10 of 15 cases (67%), with the smallest lesion measuring 0.5 cm. Venous sampling was performed in 15 patients, and a thymic sample obtained in 10; a twofold step-up of parathyroid hormone in thymic veins was noted in eight of 15 cases (53%), but was not localizing, as samples in other veins were elevated in all but one case. Angiography appears more sensitive than second-generation CT for detecting mediastinal glands. However, CT is very useful in patients with previous failed explorations. Scanning must include contiguous sections extending several centimeters below the carina, in order to encompass low-lying mediastinal glands.