Is the subdivision of Thy3 nodules needed? Audit reviewing the management of Thy3 nodules, and the associated malignancy rates.

Abstract

Abstract Introduction Following the 2014 update to the BAETS thyroid nodule cytology guidance, the management of Thy3 lesions was modified by subdivision into Thy3a and Thy3f categories. Both lesions remain indeterminate but are proposed to have differing risks of malignancy when counselling patents: these risks have been called into question by subsequent data. Methods This, retrospective, Audit aimed to review the management of Thy3 (Thy3a and Thy3f) cytological diagnoses, within an NHS Trust, and compare this to the BAET Guidance 2014. Further, malignancy rates for Thy3a and Thy3f cytology were made over the calculated over the period.118 patients with a Thy3 cytology identified between 2014 and 2019. Data separated into data pre-2015 and 2015 onwards. Results In 2014, 29% of Thy3a nodules were managed in line with 2014 BAETS guidance. This improved to 34% from 2015. Meanwhile, Thy3f diagnoses were managed mostly in favour of the BAETS guidelines – 83% in 2014 and 92% 2015 onwards. The malignancy rates found, amongst all 118 patients, were 17.2% and 14.8% for Thy3f and Thy3a nodules respectively. Conclusions At this institution, Thy3 cytological diagnoses, regardless of classification into Thy3a or Thy3f, were largely treated in the same way (by a diagnostic hemi-thyroidectomy). The management of the nodules may reflect a variety of factors, including how comfortable patients and surgeons are when handling uncertainty. With malignancy rates for both Thy3a and Thy3f nodules being much the same, it is not surprising that they are managed in a similar way.