Fine-Needle Aspiration Diagnoses of Noninvasive Follicular Variant of Papillary Thyroid Carcinoma

Abstract

If NFVPTCs were no longer termed carcinomas, this would affect the rate of malignancy of FNA diagnostic categories. Cytologic and molecular features could aid in identifying NFVPTCs at the time of FNA diagnosis.

Preoperative Cytologic Diagnosis of Noninvasive Follicular Thyroid Neoplasm with Papillary-Like Nuclear Features: A Prospective Analysis

“…To determine whether this distinction can be made in a reliable manner, we prospectively classified aspirates originally diagnosed as ''suspicious for malignancy'' or ''malignant'' using criteria we had previously identified as helpful in distinguishing between NIFTP/FVPTC and cPTC (8). These criteria were sufficient to permit classification as either NIFTP/FVPTC or cPTC in 87.5% (49/56) of cases with accurate distinction between cPTC and other follicular patterned lesions (including NIFTP, FVPTC, and follicular adenoma) in 94% (46/ 49) of classified cases.…”

“…Recently, members of our group published the results of a small pilot study retrospectively comparing the cytologic features of NIFTP with those of cPTC (8). The results of this study showed that NIFTP was more likely diagnosed as suspicious for malignancy rather than malignant on cytology and demonstrated a microfollicular predominant architecture.…”

The Bethesda System for Reporting Thyroid Cytopathology: Proposed Modifications and Updates for the Second Edition from an International Panel

“…Recent studies indicate that a majority of NIFTP cases are sequestered within the indeterminate categories of TBSRTC leading to a significant impact on the implied ROM [8,9,10,11]. It remains to be seen how NIFTP will be incorporated into thyroid pathology and affect management algorithms.…”

AHNS Series: Do you know your guidelines? AHNS Endocrine Section Consensus Statement: State‐of‐the‐art thyroid surgical recommendations in the era of noninvasive follicular thyroid neoplasm with papillary‐like nuclear features

“…Bizzarro et al13 concluded that NIFTP usually lacks pseudoinclusions and papillary structures; nuclear size and microfollicular clusters may allow differentiation between NIFTP and invasive FVPTC. Howitt et al17 found statistically significant differences in cytomorphologic features between patients with NIFTP and those with PTC. In their series, among PTC cases, 96% demonstrated tumor sheets, 50% had papillae, 79% had pseudoinclusions, and microfollicles were noted in only 4% of cases.…”