. Author manuscript; available in PMC: 2020 Sep 8.

Published in final edited form as: Endocr Pathol. 2019 Jun;30(2):155–162. doi: 10.1007/s12022-019-9574-7

Table 2.

Overview of the most frequent molecular changes seen in NIFTP compared to FA, PTC, E-FVPTC, and I-FVPTC

Testing method	FA	NIFTP	cPTC	E-FVPTC	I-FVPTC
Immunohistochemistry
HBME-1	⁻	⁺	⁺⁺	⁺/⁺⁺	⁺⁺
GALECTIN-3	⁻	⁺	⁺⁺	⁺/⁺⁺	⁺⁺
CD56	⁺/⁺⁺	⁻	⁻	⁻	⁻
Molecular testing
BRAF^V600E	⁻	⁺^*	⁺⁺	⁺	⁺
BRAF^K601E	⁺	⁺	⁺	⁺⁺	⁺
NRAS	⁺⁺	⁺⁺	⁺	⁺⁺	⁺⁺
HRAS	⁺⁺	⁺⁺	⁺	⁺⁺	⁺
KRAS	⁺⁺	⁺	⁺	⁺⁺	⁺
PTEN	⁺⁺	⁻	⁺	⁻	⁻
TERT	⁻	⁺^*	⁺	⁺	⁺
RET/PTC	⁻	⁺^*	⁺⁺	⁺	⁺
PAX8/PPARγ	⁺	⁺⁺	⁺⁺	⁺⁺	⁺⁺
ALK fusion	⁻	⁻	⁺	⁻	⁻
BRAF fusion	⁻	⁻	⁺	⁻	⁻
ETV6/NTRK3	⁻	⁻	⁺⁺	⁻	⁻
NTRK1/3 fusion	⁻	⁻	⁺	⁻	⁻
GEC/GSC	Mostly benign	Mostly suspicious	Frequently suspicious	Frequently suspicious	Frequently suspicious

FA, follicular adenoma; NIFTP, non-invasive follicular thyroid neoplasm with papillary-like nuclei; cPTC, classical variant of PTC; E-FVPTC, encapsulated follicular variant of PTC; I-FVPTC, infiltrative follicular variant of PTC; GEC/GSC, gene expression and gene sequencing classifier;

⁺

Sometimes present

⁺⁺

Commonly present

⁻

Absent

The detection of these genetic alterations should trigger an exhaustive search for invasive features and papillary formations