[High-resolution echography of the neck. Preoperative evaluation of lymph node metastases in patients with thyroid carcinoma].

Twenty-six patients with papillary and 4 with medullary thyroid carcinoma were examined by HRUS before surgery in order to evaluate its accuracy in detecting lymph node metastasis (N) of the neck from thyroid carcinoma. All patients underwent total thyroidectomy and nodal dissection. HRUS was accurate in 73% of cases in N staging, while clinical staging was accurate in 60% of cases only. In 50% of patients HRUS provided with interesting additional information, such as disclosing lymphadenopathy in 8 patients with no clinical evidence, proving nodal involvement in 5 cases, and showing extranodal extension in 5 cases. HRUS allowed the observation of anechoic necrotic areas and microcalcified nodes. On the other hand, according to our results, HRUS cannot either discriminate metastatic from benign nodal involvement, or identify mediastinal adenopathy. False negatives are possible due to micrometastatic areas in normal size nodes. Nevertheless, HRUS proved to be a valuable aid to complete clinical examination of the neck, and a good guide for the surgeon during nodal neck dissection.