Table 1.

Consensus diagnostic criteria of noninvasive follicular thyroid neoplasms with papillary-like nuclear features (NIFTP),

adapted from Nikiforov et al. [19]

Encapsulated or clear demarcation

Follicular growth pattern

Nuclear score 2–3

No vascular or capsular invasion

Absence of all the following features

> 1% papillae

Psammoma bodies

> 30% solid/trabecular/insular growth patterns

Tumor necrosis

High mitotic activity (≥ 3 per 10 high power fields)

Cell/morphologic characteristics of other variants of PTC, e.g. tall cell and cribriform morular variants