The efficiency of performing ultrasound-guided fine-needle aspiration biopsy following mass screening for thyroid tumors to avoid unnecessary surgery.

Thyroid masses are a common clinical finding, and their management remains controversial. The purpose of this study was to evaluate the clinical effect of performing routine ultrasound (US) examinations and US-guided fine-needle aspiration biopsy (US-FNAB) in the management of diffuse or nodular goiter diagnosed by mass screening. Mass screening carried out from 1993 to 1996 revealed 444 women with goiter, 322 of whom had diffuse goiter and 122 had nodular goiter. All of these patients underwent US examination, the results of which determined that 169 should undergo US-FNAB to confirm an accurate diagnosis of their thyroid tumors. Histological examinations after surgical resection revealed that 12 of the 322 patients with diffuse goiter (3.7%) and 23 of the 122 with nodular goiter (18.9%) had malignant tumors. Among the 61 thyroid tumors surgically verified, US-FNAB yielded a sensitivity rate of 93%, a specificity rate of 81%, and an accuracy rate of 90%. Insufficient aspiration was obtained from 5%. Performing US-FNAB-resulted in an elevation in the percentage of malignant tumors yielded at surgery of up to 72%. Thus, ultrasonography followed by US-guided-FNAB could be a useful routine method of evaluating thyroid tumors detected by mass screening. Moreover, a greater number of unnecessary thyroid operations can be avoided by performing US-FNAB rather than FNAB alone.