Endocrine Abstracts

Introduction: Thyroid sonography has become the first line diagnostic procedure for thyroid nodules. The characterization of specific sonografic patterns associated with high risk of malignancy has enabled physicians to determine which nodules are more likely to be malignant and thus merit further evaluation.

Aim: We investigated whether the ultrasonographic nodule characteristics proposed in the literature were able to predict cytology findings after ultrasound-guided fine needle aspiration biopsy (USg-FNAB), in our centre.

Materials and methods: A retrospective analysis of patients who had undergone USg-FNAB between Jan 2014 and Nov 2015 was performed. Nodules were classified according to the following sonographic characteristics a) size, b) solid hypoechoic nodule, c) presence of microcalcifications, d) irregular borders, e) vertical growth (‘taller-than-wide’ orientation), and, f) increased vascularity. Cytology reports were classified, according to the Royal College of Pathologists guidance, as non-diagnostic for cytological diagnosis (Thy 1), negative for malignancy (Thy2), neoplasm possible (Thy3), suspicious for malignancy (Thy4) and malignant (Thy5). Category Thy1 nodules were excluded from the analysis. The association of suspicious ultrasound characteristics with the composite cytology outcome of possible neoplasm, suspicious or malignant (Thy3, Thy4, Thy5) was investigated.

Results: During the study period, 736 nodules in 571 patients were biopsied. The most common ultrasonographic feature was low echogenicity (175/736, 23.8%), whereas the most rear was the vertical nodule growth (‘taller-than-wide’ appearance, (28/736, 3.8%)). In a logististic regression model, where patient age was entered along with the ultrasonographic features, all variables emerged as predictors of the composite category Thy3, Thy4, Thy5 cytology, except vertical nodule growth and increased vascularity.

Conclusion: Sonographic nodule characteristics proved to be accurate predictors of cytology in the present patient series. Thyroid ultrasonography is a useful tool in determining which nodules should be biopsied.