To determine how often preoperative localisation tests are performed on patients suffering from primary hyperparathyroidism (pHPT) without previous neck surgery and to analyse the predictive value of such tests.Retrospective study.University Hospital Utrecht, the Netherlands.From 1988 to 1993 50 patients suffering from pHPT underwent initial surgical exploration of the neck. Clinical data, performed tests and results, findings at surgery, histological findings and clinical result were recorded.Localisation tests were performed 41 times on 27 patients (54%): 19 times ultrasonography, 14 times scintigraphy, 7 times computer tomography and once, venous sampling. Independent of preoperative testing, all patients underwent systematical, bilateral exploration of the neck. In 49 patients a total of 53 enlarged parathyroid glands were removed, all patients became normocalcaemic. Exploration revealed no abnormalities in 1 patient, who received no further surgical treatment. In 15 patients (56%) the localisation tests predicted the correct side of the enlarged glands, in 5 patients the wrong side was predicted and in 7 patients no prediction was possible.These results are in accordance with the poor predictive value of localisation tests prior to initial neck exploration as mentioned in other studies. The success rate of operation by an experienced parathyroid surgeon is 95-99 per cent. Preoperative localisation studies in patients with primary hyperparathyroidism without previous neck surgery are not only of poor predictive value, but should even be discouraged, because they may mislead the operating surgeon.
