PRIMARY HYPERPARATHYROIDISM DETECTED BY PARATHYROID INCIDENTALOMA: CLINICAL FEATURES, WORK-UP AND MANAGEMENT

With the widespread use of neck ultrasound, parathyroid incidentaloma (PI) emerges as an additional opportunity for incidental detection of primary hyperparathyroidism (PHPT).

This study aimed to investigate PHPT cases detected by PI and to compare them with other PHPT patients. A retrospective analysis of newly diagnosed PHPT patients between 2014 and 2020 was conducted in our hospital.

The cohort of 124 subjects was divided in two groups: 22 (17.7%) PHPT patients detected by PI (PI PHPT group) and the rest of 102 PHPT patients (non-PI PHPT group). Overall, 21 PIs were discovered on ultrasound and one was found during thyroid surgery. Clinical features, work-up and management of two study groups were compared.

The PI PHPT group had lower ionized calcium at diagnosis (p=0.034), lower peak serum calcium during follow-up (p<0.01), less fractures (p=0.022) and was less likely to meet the international criteria for parathyroidectomy (p<0.01). Positive sestamibi scan (p=0.022) and confirmed concordant localization in at least two different parathyroid imaging techniques (p=0.033) were more likely in the PI PHPT group. The frequency of surgical management did not differ between groups.

PHPT detected by PI is clinically relevant and mostly comparable to PHPT in other patients with some features that correspond more often to a mild disease. Higher rate of positive preoperative localization in PHPT detected by PI might encourage parathyroidectomy even without the international criteria met.