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In the last two years, there has been an interesting discussion on NIFTP (Non-invasive folicular Thyroid neoplasm papillary-like nuclear features), the previous encapsulated folicular variant of papillary thyroid carcinoma (EFVPTC).
ISSN 2470-4059 http://dx.doi.org/10.17140/OTLOJ-3-137 Open Journal Letter to the Editor NIFTP: A Critical Pathologist View * *Corresponding author Sydney Correia Leão, MD * Medical Pathology Assistant Sydney Correia Leão, MD Federal University of São Paulo São Paulo, SP, Brazil Medical Pathology Assistant, Federal University of São Paulo, São Paulo, SP, Brazil E-mail: sydneyleao@hotmail.com Volume 3 : Issue 1 In the last two years, there has been an interesting discussion on NIFTP (Non-invasive folicular Article Ref. #: 1000OTLOJ3137 Thyroid neoplasm papillary-like nuclear features), the previous encapsulated folicular variant of papillary thyroid carcinoma (EFVPTC). The study of Nikiforov et al,1 laid the foundations of this new discovery, which are: Article History th Received: February 19th, 2017 rd a. The morphological features, i.e., the follicular growth pattern and nuclear features of papi- Accepted: February 23 , 2017 th llary thyroid carcinoma (PTC); Published: February 24 , 2017 b. Lack of invasion, which separates this tumor from invasive FVPTC; Citation c. Clonal origin determined by finding a driver mutation, which indicates that the lesion is Leão SC. NIFTP: A critical pathologist biologically a neoplasm; and view. Otolaryngol Open J. 2017; 3(1): 27. doi: 10.17140/OTLOJ-3-137 d. A very low risk of adverse outcome when the tumor is non-invasive. However, some practical pathological problems arose in relation to this new pathological entity: 1. During freezing procedure of thyroidectomy, it would be necessary to freeze the entire capsule to discard microscopic foci of invasion, that would change the classification of the lesion to FVPTC; 2. The NIFTP cannot be diagnosed only by fine needle aspiration cytology (FNAC).2 In this case, it is necessary to correlate the observations with the imaging findings (Thyroid US with encapsulated lesion); 3. During histological processing, it is interesting to note that the lesion is fully represented, because exclusion criteria for NIFTP such as necrosis and vascular invasion may appear focally; 4. In some developing countries, it is very difficult to perform molecular testing to confirm the mutation that is leading to this lesion.
Due to the aforementioned facts, I believe that NIFTP is a diagnosis of exclusion in patients with encapsulated lesions showing papillary nuclear characteristics and follicular ar- chitecture. I also believe that further studies should be done with an attempt to characterize this new entity, definitively separating it from the follicular variant of papillary carcinoma.