Triage of patients with AUS/FLUS on thyroid cytopathology: effectiveness of the multimodal diagnostic techniques

摘要

The management of patients with thyroid cytopathologic diagnosis of atypia (or follicular lesion) of undetermined significance (AUS/FLUS) is a complex clinical problem. The purpose of this study was to develop a practical triage scheme based on multiple diagnostic tests in general use. We performed a retrospective cohort study involving 15,335 consecutive patients with a referral diagnosis of thyroid nodule between April 2011 and March 2015 using an institutional database. We obtained 904 patients with an initial cytopathologic diagnosis of AUS/FLUS who underwent repeat fine‐needle aspiration or core needle biopsy, 388 of whom had a corresponding histopathological diagnosis for excised index lesions. The diagnostic performance of ultrasound (US) findings, repeat biopsy, and BRAF^{V 600E} mutation in cytopathologic specimens were evaluated individually or as a set. Of the 388 resected AUS/FLUS cases, 338 (87.1%) were thyroid cancer. The positive likelihood ratios (LRs) for BRAF^{V 600E} mutation and repeat biopsy result of suspicious for malignant cell (SMC) or worse were 11.6 (95% CI = 1.7–77.8) and 13.7 (95% CI = 4.6–41.0), respectively. The absence of suspicious findings on US combined with cytologic result of less than SMC or negative BRAF^{V 600E} mutation produced negative style="fixed-case">LRs ranging from 0.06 to 0.15, corresponding to negative predictive values of over 90% in both primary and referral settings. For patients with style="fixed-case">AUS/ style="fixed-case">FLUS cytopathology, clinical decision making can be guided by a simple triage scheme based on US findings, repeat biopsy, or style="fixed-case">BRAF^{V 600E} mutation.