Endocrine Abstracts

Controversy exists as to the best way to determine which thyroid nodules we should have fine needle aspiration (FNA). The lack of consensus in the British and American Thyroid Association guidelines has not helped to clarify this. The use of ultrasound scan (USS) determined U grading versus a composite of nodule size and pre-determined number of suspicious features continues to be debated. We therefore set out to compare the accuracy of U grading with other identified USS features in predicting an abnormal cytology.

A retrospective analysis Thyroid USS and FNA in 2015 was performed. Reports were analysed for calcification, echogenicity, vascularity, USS grading (U), cytology (Thy) and histology. The number of abnormal cytology in the U group was compared with that seen in other features. Data are expressed as n(%) of findings.

We identified 40USS performed (37 female, mean age range 45–60 years) for thyroid nodules (10 solitary). Scans according to U grading: 8U2, 27U3, 3U4, 2U5. There were 14 abnormal cytology (>Thy3) and these yielded 6 follicular adenoma and 4 papillary carcinoma histologically. 8(30%)U3 grading had abnormal cytology with 2 each from (90%)U4 and (100%)U5; a total of 12(92%) abnormal cytology were correctly predicted by U3 grading and above. Abnormal cytology was found if nodules had central vascularity 6(46%), calcification 5(38%) and mixed echogenicity nodules 5(38%). Abnormal cytology also reliably predicted abnormal histology in 80% of biopsies.

Our data show that the U grading of thyroid nodules is a highly predictive way of determining abnormal cytology on FNA. This predictability is better than in any single USS feature. We conclude that nodules with U3 grading and above should proceed to FNA without the need for further USS assessment. The small numbers in our study would however suggest that larger studies will need to be done to support our findings.