American Thyroid Association Guidelines on the Management of Thyroid Nodules and Differentiated Thyroid Cancer Task Force Review and Recommendation on the Proposed Renaming of Encapsulated Follicular Variant Papillary Thyroid Carcinoma Without Invasion to Noninvasive Follicular Thyroid Neoplasm with Papillary-Like Nuclear Features

Abstract

American Thyroid Association (ATA) leadership asked the ATA Thyroid Nodules and Differentiated Thyroid Cancer Guidelines Task Force to review, comment on, and make recommendations related to the suggested new classification of encapsulated follicular variant papillary thyroid carcinoma (eFVPTC) without capsular or vascular invasion to noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP). The task force consists of members from the 2015 guidelines task force with the recusal of three members who were authors on the paper under review. Four pathologists and one endocrinologist were added for this specific review. The manuscript proposing the new classification and related literature were assessed. It is recommended that the histopathologic nomenclature for eFVPTC without invasion be reclassified as a NIFTP, given the excellent prognosis of this neoplastic variant. This is a weak recommendation based on moderate-quality evidence. It is also noted that prospective studies are needed to validate the observed patient outcomes (and test performance in predicting thyroid cancer outcomes), as well as implications on patients' psychosocial health and economics.

Impact of historic histopathologic sample review on the risk of recurrence in patients with differentiated thyroid cancer

“…Currently, NIFTP is assumed to represent nearly two-thirds of the follicular variant PTCs (15,19,20). Although the ATA 2015 task force has recently proposed that this neoplasm with very low potential for recurrence should be reclassified as a non-cancer (16), and the 2 patients with NIFTP from our cohort had an excellent response to therapy Pathology review and risk of recurrence Arch Endocrinol Metab. 2018;62/2 (both treated with total thyroidectomy and radioiodine ablation), isolated cases of distant metastasis have been reported (21)(22)(23).…”

“…Two patients from this cohort were diagnosed with the encapsulated variant of follicular thyroid carcinoma, which is currently known as NIFTP (15,16). These tumors are characterized by a follicular growth pattern without papillae formation, nuclear features of papillary thyroid carcinoma, encapsulation or clear demarcation, and no vascular or capsular invasion (15).…”

Complications from tracheal resection for thyroid carcinoma

“…In locally invasive thyroid cancer, en-bloc resection of the thyroid within the tracheal segment interested by the tumor is suggested by the American Thyroid Association Guidelines since it provides a good prognosis and a significant palliation reducing the risk of asphyxiation or hemoptysis (33). However, the postoperative complication rate related to this operation is non-negligible.…”

Noninvasive Follicular Thyroid Neoplasm with Papillary-Like Nuclear Features: Can Cytology Face the Challenge of Diagnosis in the Light of the New Classification?

“…Most reported cases demonstrated an indolent behavior, and they should be treated with hemithyroidectomy without radioiodine ablation [9]. However, some authors questioned the indolent nature of NIFTP [6, 10, 11].…”

“…NIFTP were well-delimitated or encapsulated lesions, and all of them were fully sampled. Neither capsular infiltration (as defined by Haugen et al [9]) nor lymphovascular invasion was seen. Main macroscopic features of NIFTP cases were collected for the study.…”