Objective: To assess the performance of neck ultrasonography (US) in the detection of lymph node lesions metastatic from differentiated thyroid carcinoma (DTC) and the detection of parathyroid adenomas.
Methods: Neck US was performed in 667 patients with DTC (173 men and 494 women; mean age, 47.7 years). In cases of suspicious neck nodes, US-guided fine-needle aspiration biopsy (US-FNAB) plus measurement of thyroglobulin in the needle washouts (FNAB-Tg) was done. In addition, 75 patients with primary hyperparathyroidism (pHPT) (15 men and 60 women; mean age, 56 years) underwent neck US and sestamibi scintiscanning for localization of parathyroid adenoma. For confirmation of US findings, US-FNAB plus measurement of parathyroid hormone in the needle washouts (FNAB-PTH) was performed. FNAB-PTH was also measured in 129 suspected parathyroid adenomas incidentally detected in a series of 4,129 patients undergoing neck US examination for thyroid disease.
Results: The presence of DTC metastatic lesions was confirmed in 46 of 95 patients with suspicious neck nodes. US sensitivity and specificity were 82.1% and 91.2%, respectively. The positive predictive value (PPV) of US-FNAB + FNAB-Tg was 94.7%. In the 75 patients with pHPT, US followed by US-FNAB + FNAB-PTH showed a higher PPV (97.5%) in comparison with sestamibi scintiscanning (83.7%) in the detection of parathyroid adenoma. A parathyroid adenoma was also incidentally detected in 0.62% of the 4,129 patients undergoing neck US for thyroid disease.
Conclusion: US accurately detects DTC neck metastatic lesions and localizes parathyroid adenomas. Moreover, neck US may lead to discovery of parathyroid incidentalomas.