Bilateral exploration in primary hyperparathyroidism: Double adenoma distribution and biochemical patterns over two decades

Background We investigated if anatomic patterns of abnormal parathyroid glands have ch anged for primary hyperparathyroidism (pHPT) as atypical biochemical presentation (normohormonal and normocalcemic) has increased. Methods Retrospective review of patients with pHPT who underwent routine bilateral neck exploration. Results 2762 patients were included. The “late” cohort (2014–2020) exhibited lower preoperative calcium (10.8 vs 11.1 ​mg/dL; P ​= ​0.001) and PTH levels (101 vs. 146 ​pg/mL; P ​= ​0.001) compared to the “early” cohort (2000–2006). Patients with atypical biochemical profiles increased from 25.5% to 31.3% (P ​< ​0.001). The prevalence of single adenoma (SA) decreased (66.1% vs 58.9%, P ​= ​0.02) while the proportion of double adenoma (DA) increased (17.3% vs. 22.6%, P ​< ​0.01). Upper parathyroid adenoma(s) remained the most common finding for SA and DA in both time points. Conclusions Despite changes in patient characteristics, single upper adenoma and bilateral double upper adenomas remain the most common findings for patients with pHPT.