[Primary hyperparathyroidism: significance of its preoperative localization].

The diagnostic accuracy of locating parathyroid tumors preoperatively was studied by reviewing 27 cases of hyperparathyroidism experienced at our Department between 1965 and 1983. Computed tomography gave the most accurate prediction (69%), followed by venous sampling for PTH (33%), subtraction scintigraphy with 201T1 and 123I (30%), ultrasonography (29%) and palpation (7%). Although the time required for an operation was not changed, significantly fewer parathyroid glands identified were removed during the operation when they had been located accurately before operation. This enabled quick recovery from postoperative hypocalcemia and ensured a safer operation. Scintigraphy and ultrasonography must first be performed in patients suspected of having hyperparathyroidism, but computed tomography is essential before operation. Venous sampling is indicated only when all other tests are negative, or in cases of re-operation.