To investigate the utility of conventional ultrasound and contrast-enhanced ultrasound (CEUS) in the diagnosis of thyroid metastases (TM), aiming to enhance the imaging-based recognition and clinical diagnostic accuracy among ultrasound physicians.

This retrospective study analyzed 17 cases of TM confirmed by histopathological examination at the First Affiliated Hospital of Soochow University from January 2015 to December 2024. Clinical characteristics were systematically documented, and ultrasound images were independently reviewed by two experienced radiologists. The study primarily assessed conventional and contrast-enhanced ultrasonographic features of TM.

Seventeen patients with pathologically confirmed TM were included. The primary tumors originated from lung cancer and esophageal cancer in 5 cases each (29.41%), laryngeal cancer in 3 (17.65%), and nasopharyngeal carcinoma, pancreatic cancer, thoracic chondrosarcoma, and breast cancer in 1 case each (5.88%). Clinically, rapid lesion enlargement within a short interval was observed in 7 patients (41.18%), dyspnea in 4 (23.53%), hoarseness in 10 (58.82%), and dysphagia in 8 (47.06%). Conventional ultrasound revealed unilateral lobe involvement in 14 patients (82.35%) and bilateral involvement in 3 (17.65%). Most lesions were nodular (88.24%, 15/17), hypoechoic (82.35%, 14/17), and characterized by ill-defined or irregular margins or extrathyroidal extension (88.24%, 15/17); 2 cases (11.76%) presented with a diffuse pattern. Cystic-solid composition was detected in 8 cases (47.06%), coarse calcifications in 4 (23.53%), and microcalcifications in 6 (35.29%). Among the 10 patients with complete CEUS data, 8 (80.00%) exhibited heterogeneous enhancement and 8 (80.00%) demonstrated perfusion defects. Enhancement intensity was equally divided between low enhancement and iso-/hyperenhancement (50.00% each).

TM exhibit distinct conventional ultrasound and CEUS features. When integrated with clinical history, multimodal ultrasound evaluation significantly enhances early detection and diagnostic accuracy of TM.