Sonographic Features of Cervical Lymph Nodes After Thyroidectomy for Papillary Thyroid Carcinoma

Objectives Unlike the preoperative findings in patients with papillary thyroid carcinoma, the postoperative sonographic features of cervical lymph nodes have not been established. This study aimed to assess the sonographic features of metastatic lymph nodes after thyroidectomy for papillary thyroid carcinoma. Methods The study population consisted of 104 consecutively registered patients who had undergone thyroidectomy for papillary thyroid carcinoma and underwent sonographically guided fine‐needle aspiration of lymph nodes in the neck. The sonographic features of each lymph node were retrospectively evaluated by a single radiologist. The confirmation methods for the 115 lymph nodes included surgery (n = 35), measurement of thyroglobulin levels in the aspirates (n = 2), malignant cytologic analysis (n = 10), and benign cytologic analysis with sonographic follow‐up over 12 months (n = 68). We determined the diagnostic indices of individual sonographic features for differentiating between metastatic and benign lymph nodes by comparing these features with the final diagnoses. Results Of the 104 patients, 67 underwent at least 1 cycle of radioisotope therapy after thyroidectomy. The malignancy rate for the lymph nodes was 42.6% (49 of 115). A significant relationship was found between malignancy and the presence of an intranodal cystic component, intranodal microcalcifications, diffusely increased echogenicity, a microlobulated margin, a round shape, loss of echogenic hila, and mixed or central vascularity on color Doppler sonography ( P < .05). Conclusions The sonographic features of metastatic cervical lymph nodes in postoperative patients with papillary thyroid carcinoma were similar to those in preoperative patients.