Endocrine Abstracts

Objectives: Preoperative detection of parathyroid gland adenomas in patients diagnosed with primary hyperparathyroidism (pHPT) represents a diagnostic challenge. The aim of the study was to assess the utility of contrast-enhanced ultrasound (CEUS) as the diagnostic tool for preoperative localization of parathyroid gland adenomas in conjuction with a conventional ultrasonography.

Methods: Between the years 2021 and 2022, 33 adult patients (30 women and 3 men, aged 37-79) diagnosed with pHPT, underwent high-resolution ultrasound (US) and CEUS of parathyroid gland adenomas preoperatively. During CEUS examination 1.5 ml of SonoVue contrast was administered intravenously. All patients were qualified to surgical treatment according to laboratory and imaging findings in a combination with clinical symptoms and underwent parathyroidectomy with histopathologic confirmation of parathyroid adenomas. Analysis of the B-mode features involved size, echogenicity, calcifications, cystic components and vascularity patterns assessed in color Doppler and superb microvascular imaging. Secondly contrast distribution in CEUS examination was evaluated in real-time and retrospectively. Qualitative contrast patterns assessed in CEUS involved: homo- or heterogenous enhancement; hyper- or hypoenhancement; distribution of contrast in wash-in phase (centripetal, centrifugal or combined) and in wash-out phase (centrally, peripherally or combined).

Results: Histopathologic results included 33 parathyroid adenomas (involved two cases of atypic adenomas) in 30 women and 3 men, the medium size 11.6 mm (±6.9) and volume 2.1 mm³ (±2.3). In conventional US examination the majority of lesions were assessed as hypoechoic (n=36; 100%) with dominant inhomogenous echostructure (n=18; 54.5%), mixed vascularity (n=22; 66.6%) and polar vessel observed in 14 lesions (42.4%). Dominated qualitative features assessed in CEUS involved homogenous (n=22; 66.6%) and hyperenhancement (n=25; 75.7%), with centripetal distribution of contrast in wash-in phase (n=24; 72.7%) and dominant centrally wash-out of the contrast (n=19; 57.5%).

Conclusions: The study indicates that CEUS examinations in conjuction with the high-resolution ultrasonography facilitated the detection of parathyroid adenomas. The use of CEUS qualitative features is advised to improve the localization of suspected parathyroid lesions preoperatively. Further studies should be performed to introduce CEUS patterns in the diagnostic algorithm of primary hyperparathyroidism.