Malignancy rates and initial management of Thy3 thyroid nodules in a district general hospital: The ‘Reading’ experience

BACKGROUND: Ultrasound‐guided fine‐needle aspiration cytology is the gold standard for investigating thyroid nodules. Stratifying the Thy3 thyroid nodule risk of malignancy is essential for clinical decision‐making. According to the Royal College of Pathologists Guidance (2016), the rate of malignancy for Thy3a is 5–15% and for Thy3f 15–30%. Our aim was to investigate the malignancy rate and the initial management of Thy3 nodules in our institution. METHODS: A retrospective review was undertaken of 115 patients with Thy3 cytology results from thyroid fine‐needle aspirations performed between January 2015 and June 2020 at a single centre. A total of 90 out of 115 patients underwent surgery. RESULTS: Of the 90 patients, we had a 40% malignant rate (36/90). Specifically, 14 of 34 (41.1%) Thy3a and 22 of 56 (39.2%) Thy3f nodules were malignant. Of the malignant lesions, 52.7% (19/36) were follicular thyroid carcinoma. 58.8% (10/17) of male patients and 35.6% (26/73) of female patients had a malignant histology. Eighteen patients eventually needed a completion thyroidectomy. CONCLUSION: Compared with national data, we showed a higher risk of malignancy in Thy3 nodules in our centre. Our study should encourage other centres to audit their own data. We propose setting up a national Thy3 registry as a basis to promote research in improving preoperative diagnosis of indeterminate thyroid nodules.