Diagnostic utility of repeat fine needle aspirations of benign thyroid nodules

Abstract

Objective: This study aims to analyze the diagnostic utility of multiple repeat FNA on thyroid nodules with initially benign diagnosis. Methods: In a 5-year period, 1658 thyroid nodules with initially benign FNAs were retrospectively reviewed and followed for subsequent resection and repeat biopsy. Results: Out of 2150 thyroid nodules, 1658 (77.1%) were diagnosed as benign on FNAs. The average age at diagnosis was 57.4 years (range: 11–93 years), and most were females (83.8%). Repeat FNA was performed on 183 benign nodules, of which 141 (8.5%) were sampled a second time and 42 (2.5%) had two or more repeat samplings. For the benign nodules without repeat FNAs, 124 had benign resection. Of cases with one-time repeat FNA, most (n = 101) remained benign on repeat FNAs, 13 of which were benign on resection. Eleven had atypical repeat FNAs, five were resected, four of which were benign and one was atypical follicular neoplasm with HRAS and TERT promoter mutations. Of cases with multiple repeat FNA, most (n = 35) were still benign on repeat FNAs, one had benign resection. Two had atypical repeat biopsies, one was PTC on resection with CCD6::RET fusion. The positive predictive value significantly decreased from 41.1% on single FNA to 8.3% on one-time repeat (P < 0.001) and 16.7% on multiple repeat (P = 0.002). The total cost for the work-up of previously benign nodules was $285,454. Conclusions: Repeat FNA biopsies did not provide an additional diagnostic value in the evaluation of benign thyroid nodules, and often led to unwarranted follow-up procedures and significantly increased health-care cost.

Keywords

• thyroid
• thyroid nodule
• aspiration biopsy
• fine needle aspiration