Noninvasive Follicular Thyroid Neoplasm with Papillary-Like Nuclear Features (NIFTP): Application of Diagnostic Criteria

Dr. Pallavi Agrawal; Dr. Manish Kumar; Dr. N K Bariar

Volume : IX, Issue : IV, April - 2020

Noninvasive Follicular Thyroid Neoplasm with Papillary-Like Nuclear Features (NIFTP): Application of Diagnostic Criteria

Dr. Pallavi Agrawal, Dr. Manish Kumar, Dr. N K Bariar

Abstract :

Noninvasive follicular thyroid neoplasm with papillary–like nuclear features (NIFTP) is an encapsulated or clearly delimited, noninvasive neoplasm with a follicular growth pattern and nuclear features of papillary thyroid carcinoma (PTC). In 2015, an international thyroid working group re–evaluated NI–EFVPC and its diagnostic criteria. The new terminology of "noninvasive follicular thyroid neoplasm with papillary–like nuclear features" (NIFTP) was accordingly introduced to replace NI–EFVPC. It is considered a ‘premalignant’ lesion of the RAS–like group. Ultrasonography (US), cytology and molecular tests are useful to suspect thyroid nodules that correspond to NIFTP but there is wide overlap of the results with the encapsulated follicular variant of PTC (E–FVPTC). In these nodules that possibly or likely correspond to NIFTP, if surgery is indicated, lobectomy is favored over total thyroidectomy. The diagnosis of NIFTP is made after complete resection of the lesion by observing well–defined criteria. While the definition of NIFTP is based on specific morphological parameters, recent studies have questioned whether the criterion allowing less than 1% of true papillae should be revised to a total absence of papillae. Since NIFTP is not ‘malignant’, tumor staging is not necessary and patients are not submitted to thyroid cancer protocols or guidelines. Recent revisions in the morphological criteria for NIFTP emphasize the need to adhere to very stringent histomorphologic criteria when making a diagnosis of NIFTP.