We audited endocrinologist consultations on patients attending a referral clinic for assessment and review of thyroid nodules and thyroid cancer follow-up, between January 2018 and December 2019. 309 patients were seen: established thyroid cancer (121), clinically-apparent nodules (104), and incidental nodules (84), with mean age 59 years (226 female). 195 patients with all data available in the electronic medical record were analyzed: established thyroid cancer (45), clinically-apparent nodules (78), and incidental nodules (72). Ultrasonography (US) was analyzed by Thyroid Imaging Reporting and Data System (TIRADS) and cytopathology by the Australian Modified Bethesda Criteria (AMBC).
After initial assessment, 154 nodules in 118 individuals underwent cytological examination: 12 AMBC-I, 72 AMBC-II, 12 AMBC-III, 14 AMBC-IV, 8 AMBC-V, 36 AMBC-VI. 41 patients with 58 nodules (4 AMBC-I, 11 AMBC-II, 1 AMBC-III, 7 AMBC-IV, 5 AMBC-V, 30 AMBC-VI) proceeded to thyroidectomy with 48 nodules showing malignant histology. A further 15 patients underwent hemithyroidectomy for 16 nodules with 14 being malignant (6 AMBC-III, 2 AMBC-IV, 1 AMBC-V, 5 AMBC-VI), i.e. 62/154 (40%) of initially biopsied nodules were malignant. Results for 36 nodules (27 individuals) resulted in discharge from follow-up (2 AMBC-I, 33 AMBC-II, 1 AMBC-IV with poor prognosis from additional malignancy).
Of remaining patients, after one further US, biopsy was performed for 31 nodules in 25 patients, with subsequent thyroid surgery in seven patients and histologically-confirmed malignancy in five (surgery for compressive symptoms in three). Continued follow-up for a mean of 48 months in the remaining patients identified one further malignancy.
We conclude 1) there was a high yield of malignancy in those submitted to surgery; 2) there is a very low rate of malignancy in those not submitted to surgery after the initial or one subsequent assessment, over 4 years follow-up; 3) criteria for serial follow-up should be revised to reduce unnecessary review.