1Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea. jhshin11@skku.edu 2Department of Laboratory Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea. 3Division of Endocrinology and Metabolism, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
Published online: March 1, 2010.
ABSTRACT
PURPOSE: We aimed to evaluate a possible role for BRAF(V600E) mutation analysis of aspiration specimens in the work up of thyroid nodules classified as indeterminate on US. MATERIALS AND METHODS: A total of 122 nodules from 122 patients were prospectively classified as indeterminate nodules based on US findings. US-guided fine needle aspiration (FNA) was done for all 122 nodules. The presence of a BRAF(V600E) mutation in FNA specimens was determined by allele-specific PCR. RESULTS: US-indeterminate nodules were confirmed as malignant in 20.5% (25/122) of cases and benign in 76.2% (93/122) after FNA or surgery. A few (3.3% (4/122), remained indeterminate. A BRAF(V600E) mutation was identified in 14.8% (18/122) of USindeterminate nodules. Of those 18 nodules, three were benign and 13 were malignant after the initial FNA. One (0.8%, 1/122) with an initially benign cytology and a BRAF(V600E) mutation was confirmed to be malignant after surgery. The remaining two benign nodules with a mutation were not followed-up. All 9 initial FNA-nondiagnostic nodules were mutation negative but 2 (11.8%) of 17 indeterminate nodules on initial FNAs were mutation positive. CONCLUSION: BRAF(V600E) mutation analysis prevents false negative cytology for only 0.8% of cases and reduces ambiguous diagnoses for 1.6% of all US-indeterminate thyroid nodules. Therefore, adding BRAF(V600E) mutation analysis to FNA for US-indeterminate nodules is of limited usefulness.