Sonographic Features of Well-Differentiated Thyroid Cancer Recurrence in the Thyroid Bed After Thyroidectomy

Thyroid cancer is the most common endocrine malignancy, with a steadily increasing incidence. Well-differentiated thyroid carcinoma, comprising papillary and follicular types, has an excellent prognosis but a relatively high recurrence rate, predominantly as local recurrence in the thyroid bed or cervical lymph nodes. Current surveillance relies on serum thyroglobulin measurement and ultrasound, both of which are accessible but prone to false-positive findings due to benign postoperative changes. This study aimed to identify ultrasound features of well-differentiated thyroid cancer recurrence in the thyroid bed after thyroidectomy and to compare the sensitivity of ultrasound with serum thyroglobulin for recurrence surveillance.

In this retrospective study, we examined the sonographic features of thyroid bed lesions in two groups of patients (the recurrence group and the non-recurrence group) who had well-differentiated thyroid cancer from 2015 to 2023. The correlations between the sonographic features and recurrence were examined using the univariate and multivariate logistic regression analyses.

A total of 260 lesions were identified from 184 patients, with 32 in the recurrence group and 228 in the non-recurrence group. Certain sonographic features were significantly associated with recurrence, including microcalcification, hypoechogenicity, cystic components, lesion size ≥ 5 mm, internal vascularity, and taller-than-wide shape. Ultrasound examination (in lesions ≥ 5 mm) combined with thyroglobulin measurement had 100% sensitivity for identifying recurrence.

Certain sonographic features, including microcalcification, hypoechogenicity, cystic components, lesion size ≥ 5 mm, internal vascularity, and a taller-than-wide shape, were associated with thyroid carcinoma recurrence after thyroidectomy. Therefore, ultrasound examination should be performed in combination with thyroglobulin assessment for the early detection and effective surveillance of local recurrence.