Comprehensive analysis for diagnosis of preoperative non-invasive follicular thyroid neoplasm with papillary-like nuclear features

Can we diagnose noninvasive follicular thyroid neoplasm with papillary-like nuclear features before surgery?

Noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP) can be differentiated from invasive encapsulated follicular variant of papillary thyroid carcinoma (eFV-PTC) by the presence of a tumor capsule or blood vessel invasion in histological examination. The objective of this study was to investigate whether it is possible to distinguish between NIFTP and invasive eFV-PTC before surgery. Patients diagnosed with NIFTP and invasive eFV-PTC from 2017 to 2023 were analyzed for biochemical, ultrasonographic, and cytological features. No differences were found in thyroid function tests, thyroid autoantibody levels, tumor size, or ultrasonographic characteristics. However, patients with invasive eFV-PTC had higher preoperative neutrophil-to-lymphocyte ratio (NLR) values and a higher Bethesda cytology category compared to those with NIFTP. In the multivariable analysis, NLR was the only significant predictor of invasive eFV-PTC. Nevertheless, there was no reliable NLR cutoff for distinguishing between the two entities. Overall, this study substantiates considerable overlap in demographic and clinical data between NIFTP and invasive eFV-PTC. Although the higher NLR observed in thyroid cancer does not provide strong discrimination, it suggests that the invasive nature of tumor cells might elicit a more profound systemic inflammatory or immune response.

NIFTP-adjusted risk estimation of Bethesda thyroid cytology categories should consider the indication for FNA according to TIRADS

BACKGROUND

Non-invasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP) was firstly described in 2016. Since NIFTP is thought a non-malignant tumor, the Bethesda system for thyroid cytology proposes two estimations of risk of malignancy of the diagnostic categories, one considering NIFTP as cancer and another one considering it as a benign neoplasm. The present study aimed to review NIFTPs in a single center, re-assess them across categories of three Thyroid Imaging Reporting and Data Systems (TIRADSs), and define the indication for biopsy according to the category-specific size cut-offs.

METHODS

The study period was from 2017 to 2023. The institutional database was searched for histologically proven NIFTPs with preoperative ultrasound images. NIFTPs were re-assessed according to the American College of Radiology (ACR), European (EU), and Korean (K) TIRADSs. The indication for biopsy was defined according to TIRADS category-specific size threshold.

RESULTS

Twenty NIFTPs from 19 patients were included. The median size of the NIFTPs was 23 mm. According to ultrasound, 80-85% of NIFTPs were at low-intermediate risk and 5-15% at high risk without significant difference among the tree TIRADSs (p = 0.91). The indication for FNA, according to three TIRADSs, was found in 52-58% of cases with no significant difference among systems (p = 0.96).

CONCLUSION

NIFTPs have heterogeneous presentation according to TIRADSs with very low indication rate for FNA.

Detailed fine needle aspiration cytopathology findings of noninvasive follicular thyroid neoplasm with papillary-like nuclear features with nuclear grading correlated to that of biopsy and Bethesda category and systematic review

BACKGROUND

Noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP) poses diagnostic challenge in fine needle aspiration cytopathology (FNAC). We aimed first to document our FNAC Bethesda categories (BCs) for all of our NIFTPs and compare our findings with those in the literature with series containing at least 14 cases each.

METHODS

Cases with final histopathological diagnoses of NIFTP and their preoperative FNAC were retrieved from 2006 to 2022 and our cytopathological BCs were documented. Then the slides were re-reviewed in a blinded manner for detailed classification and the results of both the BCs and blinded reclassification were compared with series in the literature for both BCs and detailed cytopathological review of the cases.

RESULTS

Thyroid FNACs of 43 out of 86 patients with final NIFTP diagnoses were obtained. Females composed 72.1% (F/M: 31/12); mean age and mean tumor diameter was 47.6 (19-72 years) and 23.4 mm (7-60 mm), respectively. Totally 81.4% (35/43) were classified in the "indeterminate" diagnostic categories; namely 44.2% (19/43) were reported as atypia of undetermined significance (AUS; BC III), 20.9% (9/43) were follicular neoplasm (FN; BC IV), and 16.3% (7/43) were suspicious for malignancy (SM; BC V). No patient was diagnosed as positive for malignancy (BC VI), preoperatively. Detailed cytomorphologic reevaluation revealed heterogeneous cytopathologic findings and nuclear grade (especially nuclear enlargement, membrane irregularity and elongation) significantly increased with respect to BCs. Systematic review confirmed extremely heterogeneous cytomorphologic nature of NIFTP.

CONCLUSIONS

NIFTPs were categorized most frequently as AUS, followed by FN and SM on FNAC. Our re-review were not able to specify features solely unique to NIFTP alone but may distinguish these cases from classic papillary thyroid carcinoma.

Clinical and Sonographic Features of Noninvasive Follicular Thyroid Neoplasm With Papillary-Like Nuclear Features: A Retrospective Study

ABSTRACT

This study was designed to investigate the clinical and sonographic features of noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTPs) as compared with classical papillary thyroid carcinoma (cPTC), follicular adenoma (FA), and follicular thyroid carcinoma (FTC). A total of 178 patients were enrolled in this study. The clinical characteristics and sonographic features of thyroid nodules were compared between NIFTP and cPTC or FA/FTC. All nodules were reclassified according to the Thyroid Ultrasound Imaging Reporting and Data System and American Thyroid Association guidelines classification. The mean size of NIFTP was 29.91 ± 14.71 mm, which was larger than that of cPTC ( P = 0.000). Significant difference was found in lymph node metastases between NIFTP and cPTC ( P = 0.000). Most NIFTPs showed solid composition, hypoechoic echogenicity, smooth margin, wider than tall shape, none echogenic foci, absence of halo, and perinodular vascularity, which were similar with FA and FTC. Compared with NIFTP, hypoechoic and very hypoechoic, taller than wide, irregular margin, punctate echogenic foci, absence of halo, and low vascularity were more commonly observed in cPTC. There were statistical differences both in American College of Radiology Thyroid Ultrasound Imaging Reporting and Data System and in American Thyroid Association classification between NIFTP and cPTC ( P < 0.05), but there were no significant differences between NIFTP and FTC/FA ( P > 0.05). The ultrasonographic characteristics of NIFTP were obviously different from cPTC but overlapped with FTC and FA. Ultrasound could help increase preoperative attention of NIFTP in an appropriate clinical setting, which may lead to a more conservative treatment approach.

Cytological Features of "Non-Invasive Follicular Tumour with Papillary like Nuclear Features" - A Single Institutional Experience in India

Background

The term noninvasive follicular tumor with papillary-like nuclear features (NIFTP) was introduced as a surrogate for noninvasive encapsulated follicular variant of papillary thyroid carcinoma with a defined set of histopathologic criteria. There are very few studies depicting the cytological cues for the diagnosis of NIFTP. The objective of the study was to determine the spectrum of cytological features in fine needle aspiration cytology (FNAC) smears of cases histopathologically diagnosed as NIFTP.

Methods

This was a retrospective cross-sectional study conducted over a duration of four years between January 2017 and December 2020. All surgically resected cases (n-21), who met the diagnostic criteria of NIFTP on histopathology and who underwent preoperative FNAC were included and reviewed in the study.

Results

Out of a total of 21 cases, at FNAC, diagnosis of benign, suspicious for malignancy, follicular variant of papillary thyroid carcinoma, and classic papillary thyroid carcinoma (PTC) was rendered in 14 (66.6%), 2 (9.5%), 2 (9.5%), and 3 (14.28%), respectively. Scanty cellularity was noted in 12 (57.1%) cases. Papillae, sheets, and microfollicles were seen in 1 (4.7%), 10 (47.6%), and 13 (61.9%) cases, respectively. Nucleomegaly, nuclear membrane irregularities, nuclear crowding, and overlapping were seen in 7 (33.3%), 9 (42.8%), and 9 (42.8%), respectively. Nucleoli, nuclear grooving, and inclusions were seen in 3 (14.2%) 10 (47.6%), and 5 (23.8%) cases, respectively.

Conclusion

At FNAC, NIFTP can be found in every category of The Bethesda System for Reporting Thyroid cytopathology (TBSRTC). Nuclear membrane irregularities, nuclear grooving, mild nuclear crowding, and overlapping were noted in a modest number of cases. However, the absence or rare occurrence of features such as papillae, inclusions, nucleoli, and metaplastic cytoplasm may help prevent an overdiagnosis of malignancy.

Noninvasive Follicular Thyroid Neoplasm with Papillary-like Nuclear Features (NIFTP): Tumour Entity with a Short History. A Review on Challenges in Our Microscopes, Molecular and Ultrasonographic Profile

Since Noninvasive Follicular Thyroid Neoplasm with Papillary-like Nuclear Features (NIFTP) was introduced as a new thyroid tumour entity, many studies, and meta-analyses on diagnosing NIFTP have been published. NIFTP-revised histopathological criteria emerged in 2018. NIFTP is defined as a histological entity and its diagnosis requires a careful histological examination. Its molecular profile is similar to follicular-like tumours. Ultrasound features are unable to differentiate NIFTP. NIFTP is not a cytological diagnosis, but it influences the risk of malignancy in several categories of The Bethesda System for Reporting Thyroid Cytopathology terminology.

Non-Invasive Follicular Thyroid Neoplasm with Papillary-Like Nuclear Features Is Not a Cytological Diagnosis, but It Influences Cytological Diagnosis Outcomes: A Systematic Review and Meta-Analysis

BACKGROUND

A low-risk thyroid tumour, non-invasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP) was introduced in 2016. NIFTP criteria require a thorough histological examination to rule out capsular and lymphovascular invasion, which denies the possibility of preoperative cytological diagnosis. Nevertheless, since the adoption of the new entity, the cytology of NIFTP has been a subject of interest.

OBJECTIVES

The present systematic review and meta-analysis investigate the cytological diagnosis of NIFTP.

METHOD

An online PubMed literature search was conducted between March 1, 2020, and June 30, 2020, for all original articles considering the cytology of histologically proven NIFTP. The studies including data on fine needle aspiration specimens classified by The Bethesda System for Reporting Thyroid Cytology (TBSRTC) categories, risk of malignancy (ROMs) in the TBSRTC categories, and cytomorphological features of NIFTP were included in the meta-analysis. Non-English studies and case reports were excluded. The data were tabulated and statistical analysis was performed with Open Meta-Analyst program.

RESULTS

Fifty-eight studies with a total of 2,553 NIFTP cases were included in the study. The pooled prevalence of NIFTP cases was calculated among 25,892 surgically resected cases from 20 studies and the results show that NIFTP consisted 4.4% (95% confidence interval [CI]: 3.5-5.4%) of all cases. Most of the NIFTP cases (79.0%) belonged to the intermediate categories of TBSRTC. The pooled distribution of NIFTP cases in each TBSRTC category was 1.3% (95% CI: 0.8-1.7%) in non-diagnostic (ND), 8.9% (95% CI: 6.9-10.8%) in benign, 29.2% (95% CI: 25.0-33.4%) in atypia of undetermined significance or follicular lesion of undetermined significance (AUS/FLUS), 24.2% (95% CI: 19.6-28.9%) in follicular neoplasm (FN), 19.5% (95% CI: 16.1-22.9%) in suspicious for malignancy (SM), and 6.9% (95% CI: 5.2-8.7%) in malignant. Compared to pre-NIFTP era, the pooled risk differences of ROM were reduced by 2.4% in ND, 2.7% in benign, 8.2% in AUS/FLUS, 8.2% in FN, 7.3% in SM, and 1.1% in the malignant category. The cytomorphological features of NIFTP were similar to follicular variant of papillary thyroid carcinoma (FVPTC) but lesser to papillary thyroid carcinoma (PTC).

CONCLUSIONS

Based on our results, NIFTP remains a histological diagnosis. Although cytomorphological features cannot be used in differentiating NIFTP from FVPTC, they may guide in separating NIFTP from PTC. Features such as papillae, microfollicles, giant cells, psammoma bodies, and the amount of papillary-like nuclear features should be taken into account when suspicious of NIFTP. NIFTP should not have papillae or psammoma bodies, and giant cells were rarely observed.

ANXA1 (Annexin A1) regulated by MYC (MYC proto-oncogene) promotes the growth of papillary thyroid carcinoma

Thyroid carcinoma is one of the most common endocrine malignancies, in which papillary thyroid carcinoma (PTC) is the main pathotype. ANXA1 plays a significant role in many cancer types, but how it works in PTC has not been identified. MYC is a common transcript factor involved in tumorigenesis, development, invasion, and metastasis. The relation between ANXA1 and MYC has not been proved in PTC. In this study, firstly, we analyzed the expression and prognostic value of ANXA1 in pan-cancer using the data from the UCSC database. Then we explore the role of ANXA1 in PTC, including expression, prognostic value, and immune infiltration. In addition, we evaluated the relation between ANXA1 and the transcription factor MYC. Finally, we identified the expression of ANXA1 and MYC and then evaluated their function associated with proliferation and apoptosis in PTC cell lines by CCK8 proliferation and flow cytometry apoptosis experiment. We found that ANXA1 is up-regulated in PTC comparing with normal patients. High expression of ANXA1 was associated with adverse overall survival of PTC. ANXA1 may be regulated by MYC to promote the proliferation of PTC. MYC may regulate the expression of ANXA and thus affect the proliferation of PTC.

Clinicopathological parameters for predicting non-invasive follicular thyroid neoplasm with papillary features (NIFTP)

BACKGROUND

Criteria for the preoperative diagnosis of non-invasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP) have not yet been confirmed. This study aimed to analyze differences in clinicopathological characteristics between follicular variant of papillary thyroid carcinoma (FVPTC) subtypes to determine which parameters are relevant in differentiating NIFTP from other variants.

METHODS

We retrospectively analyzed the records of 199 patients with a preoperative diagnosis of FVPTC who underwent thyroid surgery at Seoul St. Mary's Hospital (Seoul, Korea) from 2011 to 2015. Clinicopathological features were analyzed retrospectively via a complete review of medical charts and pathology reports of patients.

RESULTS

The NIFTP and invasive encapsulated FVPTC (EFVPTC) groups showed relatively benign features, with a majority of the patients categorized as Bethesda category III (25.8% and 25.6%, respectively) or IV (34.8% and 30.2%, respectively), while the infiltrative FVPTC group showed more malignant features, with more patients categorized as category V (28.6%) or VI (47.6%) (p < 0.001). BRAF ^V600E mutations were significantly less prevalent in the NIFTP group (0%) and invasive EFVPTC group (4.7%) compared with the infiltrative FVPTC group (34.9%) (p < 0.001). Multivariate analysis showed that absence of BRAF ^V600E mutation (OR 20.311, p = 0.004) and lymph node metastasis (odds ratio 10.237, p = 0.004) were significantly associated with NIFTP.

CONCLUSION

Although Bethesda category was a statistically significant factor in distinguishing FVPTC subtypes, it was not effective in conclusively distinguishing NIFTP and invasive EFVPTC. Absence of BRAF ^V600E mutation and lymph node metastasis are important features in distinguishing NIFTP from other subtypes.

Three ultrasound phenotypes of non-invasive follicular thyroid neoplasm with papillary-like nuclear features proposed for imaging-pathology analysis: single center experience

Background

The terminology "non-invasive follicular thyroid neoplasm with papillary-like nuclear features" (NIFTP) was introduced to reduce overtreatment of thyroid carcinomas with indolent behavior. However, limited literature discussed the sonographic features of the entity in depth. The objective of this study is to summarize sonographic subtypes of NIFTP for precise diagnosis.

Methods

From January 2017 to June 2020, 13,531 consecutive patients underwent surgery for thyroid nodules were reviewed; 30 patients (0.22%) with 30 NIFTP were eligible for this retrospective observational study. We evaluated ultrasound features of all the lesions and distributed them into 3 major types of ultrasound appearance using pattern recognition. Systemic literature review concerning ultrasonography of NIFTP was also performed.

Results

At sonography, all the NIFTP lesions were classified into three types: 19 (63.3%) were categorized into type A-oval and solid nodule without other high-suspicion features, 7 (23.3%) into type B-partially cystic mass without high-suspicion features, 4 (13.3%) into type C-hypoechoic solid nodule with high-suspicion features including irregular margins, microcalcifications, taller-than-wide shape.

Conclusions

Three ultrasound patterns were proposed by us for ultrasound-cytopathology correlation analysis.

Can cytology and the Thyroid Imaging, Reporting, and Data System (TI-RADS) identify noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP) before surgery?

INTRODUCTION

In 2017, the American College of Radiology (ACR) created the Thyroid Imaging, Reporting, and Data System (TI-RADS) to select thyroid nodules for fine-needle aspiration (FNA). The objective of this study is to find out whether ACR TI-RADS is useful in triaging thyroid follicular cells with papillary-like nuclear features obtained by FNA to determine the extent of surgery.

MATERIAL AND METHODS

The grayscale ultrasound of 76 noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP), 41 encapsulated (E), and 79 infiltrative (I) follicular variant (FV) of papillary thyroid carcinoma (PTC) were reviewed and assigned TI-RADS points and then suspicion levels.

RESULTS

Of the 39 tumors with high suspicion level, 32 were IFVPTC, and seven were EFVPTC. Of the 137 tumors with moderate suspicion level, 47 were IFVPTC, 34 were EFVPTC, and 56 were NIFTP. Of the 19 tumors with mild suspicion level, all were NIFTP. The only tumor with no suspicion was an NIFTP. IFVPTC had a significantly higher suspicion level than EFVPTC and NIFTP (P < 0.0001). The difference in suspicion level between EFVPTC and NIFTP is not statistically significant. None of the cases of NIFTP in the study had a high suspicion level.

CONCLUSIONS

The study demonstrates that cytology interpreted in the context of ACR TI-RADS suspicion levels can separate NIFTP from many IFVPTC and a few EFVPTC with overt invasion. PTC could be diagnosed in cytology if cells with papillary-like nuclear features derived from TR5 nodules. The nodules with TR4 or less that yield similar cells require surgical pathology to diagnose FVPTC with microscopic capsular or vascular invasions.

Noninvasive follicular thyroid neoplasm with papillary-like nuclear features: a problematic entity

Noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP) is a borderline thyroid tumour formerly known as noninvasive encapsulated follicular variant of papillary thyroid carcinoma. The prevalence of NIFTP is estimated at 4.4-9.1% of all papillary thyroid carcinomas worldwide; however, the rate of occurrence of NIFTP is eight times lower in Asian countries than in Western Europe and America. At the molecular level, NIFTP is characterised by the lack of BRAF V600E and BRAF V600E-like mutations or other high-risk mutations (TERT, TP53), and a high rate of RAS mutations, which is similar to other follicular-pattern thyroid tumours. The diagnosis of NIFTP can only be made after histological examination of the entire tumour removed during surgery, and is based on strictly defined inclusion and exclusion criteria. Although the diagnosis is postoperative, the combination of certain findings of preoperative tests including ultrasonography, cytology, and molecular testing may raise suspicion of NIFTP. These tumours can be effectively treated by lobectomy, although total thyroidectomy remains an option for some patients. Radioactive iodine and thyroid stimulating hormone suppression therapy are not required. NIFTP has an extremely good prognosis, even when treated conservatively with lobectomy alone. Nevertheless, it cannot be considered as a benign lesion. The risk of adverse outcomes, including lymph node and distant metastases, is low but not negligible.