Non-invasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP)

Non-invasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP) is a new term replacing what was previously known as non-invasive encapsulated follicular variant of papillary thyroid carcinoma (FVPTC). These tumors show benign/indolent clinical behavior when compared with invasive FVPTC, which led to their reclassification as a “non-malignant” neoplasm. NIFTP shares essentially similar cytomorphologic features as FVPTC, and can only be definitively diagnosed on surgical excision specimens. This article provides an update on morphologic characteristics of NIFTP, along with pertinent molecular studies and management algorithms.