Table 2.

Initial and revised diagnostic criteria for NIFTP according to Nikiforov et al. (4, 35).

Initial diagnostic criteria for NIFTP	Revised diagnostic criteria for NIFTP
	Primary	Secondarya
Encapsulation or clear demarcation	Encapsulation or clear demarcation	Lack of BRAF V600E mutation detected by molecular assays or immunohistochemistry
Follicular growth pattern with:  <1% papillae  No psammoma bodies  <30% solid/trabecular/insular growth pattern Nuclear score, 2–3 No vascular or capsular invasion No tumour necrosis No high mitotic activity	Follicular growth pattern with:  No well-formed papillae  No psammoma bodies  <30% solid/trabecular/insular growth pattern Nuclear score, 2–3 No vascular or capsular invasion No tumour necrosis No high mitotic activity	Lack of BRAF V600E-like mutations or other high-risk mutations (TERT, TP53)

^aSecondary criteria are helpful but not required for NIFTP diagnosis.

NIFTP, noninvasive follicular thyroid neoplasm with papillary-like nuclear features.