BRAFV600E mutation analysis of liquid-based preparation–processed fine needle aspiration sample improves the diagnostic rate of papillary thyroid carcinoma

SummaryEarly detection and diagnosis of papillary thyroid carcinoma are important for successful management of patients. Liquid-based preparations (Thinprep) of fine needle aspirations from thyroid nodules are now widely used and are replacing conventional smears because residual samples can be used for ancillary tests. Detection of the BRAFV600E mutation in cytology specimens could aid in the diagnosis of papillary thyroid carcinoma. We, therefore, analyzed the cytologic features and BRAFV600E mutation status of thyroid liquid-based preparation–fine needle aspiration samples. A total of 191 histologically confirmed thyroid liquid-based preparation–fine needle aspiration specimens were selected. We analyzed cytomorphological features and BRAFV600E mutation status in both liquid-based preparation–fine needle aspiration samples and the corresponding formalin-fixed, paraffin-embedded tissues. The Seeplex BRAF ACE detection kit (Seoul, Korea), melting curve analysis with SYBR green, and sequencing analysis were used to detect BRAFV600E mutations. Of 191 patients, 126 had histologically confirmed papillary thyroid carcinoma, whereas the remaining 65 lesions were benign lesions and carcinomas of other types. The sensitivity of liquid-based preparation alone for diagnosis of papillary thyroid carcinoma was 71.4%. When BRAFV600E mutation analyses results were considered in conjunction with the cytologic diagnosis, the diagnostic sensitivity for detecting papillary thyroid carcinoma increased to 84.9% regardless of the method used to detect BRAF mutations. BRAFV600E mutation analysis using residual liquid-based preparation cytologic samples is, therefore, a powerful additional diagnostic tool for diagnosis of papillary thyroid carcinoma.