The purpose of this study was to examine the feasibility of unilateral parathyroidectomy in patients with primary hyperparathyroidism and negative or discordant localization studies. We included in our study 72 patients with preoperative diagnosis of primary hyperparathyroidism who had negative or discordant preoperative studies. In 66 patients, studies were discordant while in six were both negative. In 40 (55.6 %) patients initial approach was a bilateral exploration. In 32 cases (44.4 %) initial surgery was a unilateral exploration: in 26 conservative approach was successful, in six mini-invasive surgery failed and a bilateral exploration was necessary due to IOPTH negative test (five cases) or to the impossibility to find a pathological gland during exploration (one case). Intra-operative PTH test showed a sensitivity of 93.2 %, a specificity of 92.3 %, and an accuracy of 93.1 %. Multiple gland disease was found in 8 (11.1 %) patients (two double adenoma and six multiple gland hyperplasia). Mean operative time was lower in unilateral exploration group (87.9 ± 43.8 min). Comparing unilateral surgery in negative or discordant studies with 77 consecutive patients who underwent focused surgery with positive and concordant studies, conversion to bilateral exploration rate was statistically significantly higher in the first group (15.6 %). We believe that unilateral parathyroidectomy can be safely performed also in patients with discordant localization studies with a high cure rate; in these cases, however, the use of intra-operative PTH is absolutely necessary. We suggest the need for referral of these patients to high-volume medical centers for thyroid and parathyroid surgery.
Keywords: Intra-operative PTH; Parathyroidectomy; Primary hyperparathyroidism; Sestamibi scintigraphy.