Challenges in neck ultrasonography: lymphadenopathy and parathyroid glands

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.

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.

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.

US accurately detects DTC neck metastatic lesions and localizes parathyroid adenomas. Moreover, neck US may lead to discovery of parathyroid incidentalomas.