Risk of thyroid carcinoma in patients treated surgically with assumed benign cytology in Riyadh, Saudi Arabia

Abstract

Objectives. This study aimed to report the rate of thyroid malignancy in benign fine-needle aspirations (Bethesda II) at King Abdulaziz Medical City and evaluate the factors that affect false-negative outcomes of FNA. Methods. All patients referred for thyroidectomy from 2009 to 2019 were reviewed (n = 1968). Only patients with a benign FNA, corresponding to the Bethesda II, were in-cluded (n = 384). Information on age, gender, body mass index (BMI), serum thyroid-stimulating hormone, type of surgery and histopathological outcomes were retrieved. Results. Of the sample (n = 384) with an initial benign FNA, 63 patients had a malignancy on postoperative pathological examination, yielding an overall false-negative rate of 16.4%. The most frequently reported histopathological type was papillary thyroid microcarcino-mas (n = 52). For the false-negative group, the mean age was 43.8 years (range 21-70 years) with an 84.1% female predominance. The surgical choice for 74% (n = 46) of cases was total thyroidectomy. Age, gender, thyroid function and BMI did not affect the false-negative rate of benign FNA (p > 0.05). Conclusions. This study found a higher risk of malignancy compared to the literature related to benign FNA. The risk of malignancy should be considered, even with benign FNA.