"Non-invasive Follicular Thyroid Neoplasm with Papillary like Nuclear Features": An Institutional Retrospective Study with Re-nomenclature and Re-classification.

The cumulative efforts of pioneers in field of Thyroid pathology have resulted in proposed reclassification of Encapsulated Follicular Variant of Papillary Thyroid Carcinoma (EFVPTC) to "Non-invasive follicular thyroid neoplasm with papillary-like nuclear features" (NIFTWP) due to indolent clinical behaviour. To study the spectrum of EFVPTCs in our institute and to reclassify them as NIFTWP using stringent morphological criteria. This is a retrospective study conducted from Jan 2014 to July 2017. Institutional records were accessed and out of 485 thyroidectomy cases, 35 cases of EFVPTC were taken into study and field's kappa was used as a means of statistical analysis. The study conducted on 35 cases of EFVPTCs using strict morphological criteria lead to re-nomenclature and re-classification of 30 out of these 35 cases, with a field's kappa value of 4.3. The present study, lead to re-nomenclature and re-classification of 30 cases of EFVPTC to NIFTWP and proved statistically that there is moderate level of Inter-observer agreement regarding the criteria used for this re-nomenclature and re-classification.