NIFTP: A Critical Pathologist View.
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).
The morphological features, i.e., the follicular growth pattern and nuclear features of papillary thyroid carcinoma.
Lack of invasion, which separates this tumor from invasive FVPTC
Clonal origin determined by finding a driver mutation, which indicates that the lesion is
biologically a neoplasm; and 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:
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.
The NIFTP cannot be diagnosed only by fine needle aspiration cytology. In this case, it is necessary to correlate the observations with the imaging findings.
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.
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 architecture.
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.
Otolaryngol Open J. 2017; 3(1): 27. doi: 10.17140/OTLOJ-3-137
