Noninvasive Follicular Thyroid Neoplasm With Papillary-Like Nuclear Features (NIFTP): Achieving Better Agreement By Refining Diagnostic Criteria

NIFTP revised: Chronicle of a change foretold

“…However, a subset of subsequent studies have demonstrated that a small percentage of patients with lesions seeming to satisfy the diagnostic criteria for NIFTP develop regional lymph node metastases. [19][20][21][22] Rosario et al 19 reported that 1 of 45 NIFTP patients in their cohort developed a lymph node metastasis, although that patient also had a concurrent papillary thyroid microcarcinoma. Parente et al 20 reported that 5 of their NIFTP cohort cases (4.9%) were associated with lymph node metastases, and 1 case developed a distant metastasis.…”

“…In the initial study defining NIFTP, the authors confirmed the very low recurrence risk for NIFTP on the basis of a retrospective analysis of cases with long‐term follow‐up. However, a subset of subsequent studies have demonstrated that a small percentage of patients with lesions seeming to satisfy the diagnostic criteria for NIFTP develop regional lymph node metastases . Rosario et al reported that 1 of 45 NIFTP patients in their cohort developed a lymph node metastasis, although that patient also had a concurrent papillary thyroid microcarcinoma.…”

Diagnostic value of HBME‐1, CK19, Galectin 3, and CD56 in the subtypes of follicular variant of papillary thyroid carcinoma

“…Adequate nuclear features of PTC were defined as two or three of the following nuclear features: (i) alteration in size and shape (nuclear enlargement/overlapping/crowding/elongation); (ii) nuclear membrane irregularities (irregular contours, grooves, pseudoinclusions); and (iii) chromatin features of PTC (clearing with margination/glassy nuclei). FVPTCs are subdivided into IFVPTC and EFVPTC, and EFVPTCs are further subdivided into invasive EFVPTC and NIFTP according to the diagnostic criteria described in previous studies . FVPTCs with invasive tongues of tumor infiltrating adjacent non‐tumor parenchyma or diffuse growth patterns were subtyped as IFVPTC.…”

“…EFVPTCs with capsular or vascular invasion were classified as invasive EFVPTC, and EFVPTCs without capsular or vascular invasion were classified as NIFTP. For exclusion criteria, tumors with any true papillae, psammoma bodies, tumor necrosis, more than two mitotic figures per 10 high‐power fields, or cell/morphologic characteristics of other variants of PTC were excluded . Cases with incomplete tumor submission for histologic examination or suboptimal tumor tissue for tissue microarray and immunohistochemical evaluation were also excluded.…”

“…FVPTCs are subdivided into IFVPTC and EFVPTC, and EFVPTCs are further subdivided into invasive EFVPTC and NIFTP according to the diagnostic criteria described in previous studies. 3,7,[27][28][29][30] FVPTCs with invasive tongues of tumor infiltrating adjacent non-tumor parenchyma or diffuse growth patterns were subtyped as IFVPTC. FVPTCs with complete or partial encapsulation or clear demarcation from adjacent non-tumor parenchyma were subtyped as EFVPTC.…”