Abstract
Purpose: To investigate the clinical and ultrasonographic features of papillary thyroid carcinoma (PTC) in the isthmus.Methods: A total of 823 patients with 823 PTCs including 133 in the isthmus and 690 in the lateral lobe were included in our study. All patients were confirmed by post-operative pathology. The clinical and ultrasonographic characteristics were retrospectively analyzed and compared. Univariate analysis and multivariate logistic regression analysis were performed.Results: Multi-factor analyses showed that PTC in the isthmus was significantly different from PTC originating from the lateral lobe in aspect ratio, microcalcification, extrathyroid extension, lymph node metastasis(LNM), lymph node density(LND) (P < 0.05, for all). There were no significant differences in age, gender, tumor size, margin, halo, echogenicity and homogeneity (P > 0.05, for all).Conclusions: The sonographic appearance of PTC in the isthmus was not typical, however, it had a higher incidence of extrathyroidal extension, central lymph node involvement and a tendency of higher lymph node density. Therefore, more careful ultrasound evaluation should be performed for these nodules.