Endocrine Abstracts

Introduction: Several studies in literature have shown that some features of thyroid nodules at US are associated with malignancy. However, previous studies were focused mainly on subjects affected by multinodular goiter (about 70%) rather than subjects with thyroid cancer (about 30%). Furthermore, the main limitation of previous studies was the lack of thyroidectomy in all subjects.

Aim of the study: To evaluate the diagnostic value of US features in a selected sample of patients with thyroid nodules cytologically suspected for malignancy (THY4–THY5) by comparing US features of each nodule with the results of histological analysis after thyroidectomy.

Methods: In this prospective study, we enrolled 54 patients with cytological result suspicious of malignancy. All subjects underwent thyroid ultrasound before thyroidectomy. We evaluated the following US features: size, content, shape, margins, echogenicity, calcification, halo sign, vascular pattern, for all the nodules (those citologically suspected and those not suspected). All enrolled patients underwent total thyroidectomy, therefore all benign and malignant nodules previously assessed at US received histological verification.

Results: In all the 54 patients a diagnosis of differentiated thyroid cancer was confirmed. Each of the following features: microcalcifications, macrocalcifications, irregular margins and hypoechogenicity at US correlate with malignancy at histology by using chi-square (P<0.001).These features have high specificity but low sensitivity (microcalcifications 93.9–40.4%, macrocalcifications 98–22.8%, hypoechogenicity 96–21% respectively). Irregular margins is the feature with the best pair of sensitivity (65%) and specificity (65%).

Conclusions: These results confirm and reinforce previous studies that showed a correlation among microcalcification, irregular margins, hypoechogenicity and malignancy in a highly selected sample of patients undergoing thyroidectomy. Furthermore, in contrast with literature, we found a strong correlation also between macrocalcification and malignancy. US is a valid tool to select which nodules require FNA evaluation according to sonographic features closely related to malignancy.

Declaration of interest: The authors declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project.

Funding: This research did not receive any specific grant from any funding agency in the public, commercial or not-for-profit sector.