Table 2. Mutations in NIFTP and other follicular neoplasms.
| Mutation/gene fusion | Follicular adenoma | NIFTP | Invasive EFVPTC | IFVPTC | Follicular carcinoma | Classic PTC |
|---|---|---|---|---|---|---|
| BRAF V600E | + | ++ | ++ | |||
| BRAF K601E | + | + | + | |||
| NRAS Q61R/K | ++ | ++ | ++ | + | ++ | |
| HRAS Q61R/K | ++ | + | + | + | + | |
| KRAS | ++ | + | + | + | + | + |
| PTEN | ++ | + | ||||
| TSHR | ++ | + | ||||
| GNAS | ++ | |||||
| TERT promoter | + | + | ||||
| RET/PTC | + | ++ | ||||
| PAX8/PPARG | + | + | + | ++ | ||
| THADA fusions | + | + | ||||
| ALK fusions | + | + | + | |||
| BRAF fusions | + | |||||
| ETV6/NTRK3 | + | + | + | |||
| NTRK1/NTRK3 | + |
+, uncommon; ++, common. NIFTP, non-invasive follicular tumor with papillary-like nuclear features; EFVPTC, encapsulated follicular variant of papillary thyroid carcinoma; IFVPTC, infiltrative follicular variant of papillary thyroid carcinoma; PTC, papillary thyroid carcinoma.