Objective: Noninvasive encapsulated follicular variant of papillary thyroid carcinoma (EFVPTC) has recently been reclassified as non-invasive follicular thyroid neoplasm with papillary-like features (NIFTP) due to their relative low risk of adverse outcomes. The purpose of this study was to evaluate the significance of the change in nomenclature from EFVPTC to NIFTP on GEC suspicious thyroid nodules.
Methods: Retrospective review of 65 consecutive patients with GEC suspicious indeterminate fine-needle aspiration cytology was performed. Of the 65 patients, 35 of the patients underwent surgery. The remaining 30 patients were awaiting surgery or refused surgery. Of the 35 patients that underwent surgery, final pathology was re-reviewed and EFVPTC were reclassified as NIFTP as appropriate. Data were analyzed accordingly.
Results: Of the 35 GEC suspicious nodules, 19 were benign (54%), 9 were NIFTP (26%), and 7 were malignant (20%). Prior to the reclassification of non-invasive EFVPTC, the prevalence of malignancy in GEC suspicious nodules was 45.7% (16/35), consistent with data from multiple institutions. After the reclassification of EFVPTC to NIFTP, the prevalence of malignancy in GEC suspicious nodules fell to 20.0%.
Conclusions: The recent change in classification of non-invasive EFVPTC to NIFTP has significant impact on the rate of malignancy of GEC suspicious thyroid nodules. The current thinking remains that NIFTP tumors warrant surgical resection, as such the training and categorization of NIFTP neoplasms as suspicious by the GEC remains correct. However, the decreased rate of malignancy with the current NIFTP nomenclature needs to be addressed with patients when discussing GEC suspicious results.