1. Encapsulation or clear demarcationa

2. Follicular growth patternb with

<1% Papillae

No psammoma bodies

<30% Solid/trabecular/insular growth pattern

3. Nuclear score 2–3

4. No vascular or capsular invasionc

5. No tumor necrosis

6. No high mitotic activityd

^aThick, thin, or partial capsule or well circumscribed with a clear demarcation from adjacent thyroid tissue.

^bIncluding microfollicular, normofollicular, or macrofollicular architecture with abundant colloid.

^cRequires adequate microscopic examination of the tumor capsule interface.

^dHigh mitotic activity defined as at least 3 mitoses per 10 high-power fields (400×).