RAS in Non Invasive Follicular Tumor with Papillary Cell Features. NIFT-P: Lobectomy is the Surgery of Choice
Paulson Vera A.,et al Thyroid. April 2017, 27(4): 506-511.
Background: Molecular testing of thyroid nodules is increasingly being utilized to guide clinical management decisions. RAS mutations are the most frequent mutations detected in the context of an indeterminate fine-needle aspiration (FNA) diagnosis. The term “noninvasive follicular thyroid neoplasm with papillary-like nuclear features” (NIFTP) was recently introduced to promote conservative management of tumors previously classified as noninvasive follicular variant of papillary thyroid carcinoma (FVPTC). This change in terminology was based on the indolent clinical behavior of these tumors and their molecular profile, which includes frequent RAS mutations. The aim of this study was to determine the percentage of RAS-mutant “carcinomas” that would now be classified as NIFTPs.
A total of 27 RAS-mutant thyroid tumors were identified. of which had an indeterminate FNA diagnosis. 20 FVPTCs, 16 (80%) would now be classified as NIFTP. NIFTPs accounted for 59% of RAS-mutant carcinomas overall and 63% of RAS-mutant carcinomas with a prior indeterminate FNA diagnosis. NIFTPs accounted for more than half of RAS-mutant “carcinomas” in this cohort. In cases where clinical and sonographic data support a low-risk phenotype, these results suggest that a lobectomy should be considered as the initial surgical approach for a nodule with an indeterminate FNA diagnosis and a RAS mutation.
Comment: Great article and we need to do less surgery on these RAS + tumors and just do a lobe.
Richard Guttler MD,FACE,ECNU