Endocrine Abstracts

Background: This study prospectively assessed the sensitivity and positive predictive value (PPV) of ultrasound (US), ultrasound-guided fine needle aspiration with PTH measurement in the needle washout (US-FNA) and sestamibi scintigraphy (SS) for the localisation of parathyroid adenomas in patients with primary hyperparathyroidism (pHPT) and features of uniglandular disease.

Methods: 51 consecutive patients with pHPT referred for first time surgery with an open minimally invasive approach (OMIP) were included. US and US-FNA and double isotope scanning with 99mTc pertechnetate and 99mTc sestamibi were performed in all patients. A localisation procedure was considered correct if surgical removal of a parathyroid gland at this.

Results: The sensitivities for correctly identifying the localisation of a hyperfunctioning adenoma were 65% (SS), 91% (US) and 68% (US-FNA).The respective PPVs were 94% (SS), 89% (US) and 96% (US-FNA). US and SS were consistent in 64%. The majority of the inconsistent studies were attributable to false-negative SS (22%). In US negative cases or if the lesion identified by ultrasound is very small (<0.25 ml), the addition of scintigraphy allowed the correct preoperative location of an adenoma in 39%. 47% of small US lesions (<0.25 ml) were correctly classified by US-FNA. 96% of the patients were cured following first surgery and and unilateral approach was succesful in 84%.Hemorrhagic and/or fibrotic changes following US-FNA were detectable intraoperatively in 28% and complicated surgery in three cases.

Conclusion: Preoperative localisation with US, SS and US-FNA allows a minimal/unilateral surgical approach in 84% of the patients. Ultrasound is significantly more sensitive and accurate than SS and US-FNA, which have a high PPV. The performance of all localisation procedures decreases in parallel to adenoma size, with ultrasound still remaining most sensitive. US-FNA, although highly specific, is complicated by a relatively high rate of haemorrhagic and/or fibrotic changes in the biopsied adenoma and should be used cautiously.