Clinical progress of noninvasive follicular thyroid neoplasm with papillary-like nuclear features / 上海交通大学学报（医学版）

In 2015, the United States and Canadian Academy of Pathology re-evaluated noninvasive encapsulated follicular variant of papillary thyroid carcinomas (NI-EFVPC), and then the new terminology of "noninvasive follicular thyroid neoplasm with papillary-like nuclear features" (NIFTP) was initially introduced to replace NI-EFVPTC. In 2017, the World Health Organization also used NIFTP in the endocrine tumor classification. NIFTP is an encapsulated or clearly delimited noninvasive neoplasm with a follicular growth pattern and nuclear features of papillary thyroid carcinoma. Ultrasonography, cytology examination and genetic test are helpful to identify NIFTP, but the results overlap with invasive encapsulated follicular variant of papillary thyroid carcinoma. This paper mainly reviews the latest research in the clinical features, diagnosis and treatment features and prognosis of NIFTP.

Noninvasive follicular thyroid neoplasm with papillary-like nuclear features: A distinct clinicopathologic entity

Objective: The objective of this study is to retrospectively evaluate follicular variant of papillary thyroid carcinoma (FVPTC) and reclassify encapsulated FVPTC as noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP) according to the criteria proposed by The Endocrine Pathology Society working group in 2015 to correlate with outcome. Materials and Methods: Retrospective review of case records of all patients diagnosed as carcinoma of thyroid between 2015 and 2016 was done for the histologic subtype. Gross and microscopic features on resected specimens of FVPTC were reviewed and subtyped as invasive and encapsulated based on capsular/vascular invasion; the encapsulated forms were further studied for size, number, follicular architecture, nuclear features, presence of psammoma bodies, stromal fibrosis, necrosis, mitoses, and lymph node status. Results: Out of the 383 patients with thyroid carcinomas in the study period, 349 were PTC which included 106 FVPTC. Thirty-three patients fulfilled the criteria to be labeled as NIFTP. Total thyroidectomy was performed in 8 patients and hemithyroidectomy in 25 patients. Lymph node dissection along with total thyroidectomy was done in 3 and completion thyroidectomy following hemithyroidectomy was done in 9. There were 29 single and 4 multiple lesions with size varying from 0.2 to 7 cm including 5 lesions measuring <1 cm. The involvement was confined to one lobe in 31 and both lobes in 2 specimens. Patients are on follow-up with no recurrence till date. Conclusion: Thyroid carcinomas currently diagnosed as FVPTC should be evaluated for criteria of NIFTP to avoid overtreatment as they have an indolent behavior.

Prevalence analysis of noninvasive follicular thyroid neoplasm with papillary-like nuclear features in a Third Class A Level Hospital in Guiyang / 中华内分泌代谢杂志

Objective To analyze of the prevalence of encapsulated follicular variant of papillary thyroid carcinoma (EFVPTC) and noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP) by 2017 World Health Organization ( WHO) classification of tumors of endocrine organs in Guiyang. Methods A retrospectively analysis of patients who had a thyroid surgery and confirmed thyroid cancer by pathological diagnosis in the Affiliated Hospital of Guizhou Medical University from 2009 to 2016. PTC and FVPTC by 2014 WHO classification of tumors of endocrine organs , and according to the 2017 WHO classification of tumors of endocrine organs ,the thyroid papillary carcinomas were reviewed and some had been confirmed as EFVPTC and NIFTP, with analysis of the prevalence and prognosis of NIFTP. Results Of the 1207 cases of thyroid carcinoma, 1150 cases were papillary carcinoma, the constituent ratio of thyroid carcinoma was 95.28％, the FVPTC was 72 cases, and the proportion of thyroid carcinoma was 5. 97％; the proportion of FVPTC in thyroid carcinoma decreased from 2009 to 2016 ( P <0.05). After pathological sections being reviewed, 10 cases had been confirmed as non-encapsulated infiltrative FVPTC, the ratio of thyroid cancer to thyroid cancer was 0.83％; EFVPTC was found in 62 cases, accounting for 5.14％ of thyroid carcinoma, these included 2 cases of NIFTP confirmed by the 2017 WHO classification of tumors of endocrine organs and 60 cases encapsulated invasive FVPTC, the percentage of thyroid carcinoma was 0.17％ and 4.97％. 62 cases of EFVPTC with the exception of 11 cases without further visit, while the remaining 51 cases of EFVPTC were followed up. Death, local or distant metastases were defined as adverse events. An adverse event was seen in 11 of 49 of the cases of invasive EFVPTC, including 2 died of disease; The NIFTP were alive with no evidence of disease. Conclusion The diagnosis of NIFTP according to new WHO classification of endocrine organ tumors in 2017 has little expected impact in Guiyang.

Pathologic basis of the sonographic differences between thyroid cancer and noninvasive follicular thyroid neoplasm with papillary-like nuclear features

Ultrasonography is pivotal in triage thyroid biopsy in the era after the identification of noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP). This pictorial essay illustrates the pathologic basis of the sonographic features that distinguish NIFTP from thyroid cancers. In this study, we present the correlations of ultrasonography to ×1 histopathology to assess shape and margin characteristics. Markedly hypoechoic nodules correlate to microfollicular/solid nodules, while isoechoic/hyperechoic thyroid nodules correlate to normofollicular/macrofollicular nodules. The ultrasound findings of NIFTP and minimally invasive encapsulated thyroid cancers are similar. Both are well-circumscribed, oval-to-round nodules with regular margins. Blurred or microlobulated margins indicate infiltrating tumors, while lobulated margins are characteristic of expansile tumors. Overtly invasive encapsulated tumors are characterized by oval-to-round nodules with irregular or lobulated margins. The ultrasound findings for infiltrative thyroid cancers show at least one of the following malignant features: marked hypoechoicity, taller-than-wide shape, microcalcifications, and blurred or microlobulated margins.

Cytologic Diagnosis of Noninvasive Follicular Thyroid Neoplasm with Papillary-like Nuclear Features and Its Impact on the Risk of Malignancy in the Bethesda System for Reporting Thyroid Cytopathology: An Institutional Experience

BACKGROUND: This study was performed to analyze cytologic diagnosis of noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP) and its impact on the risk of malignancy (ROM) in the Bethesda System for Reporting Thyroid Cytopathology (TBSRTC). METHODS: Five thousand five hundred and forty-nine cases of thyroid fine-needle aspiration cytology (FNAC) diagnosed between 2012 and 2014 were included in this study. Diagnostic categories based on TBSRTC were compared with final surgical diagnoses, and the ROM in each category was calculated both when NIFTP was included in malignant lesions and when excluded from malignant lesions. RESULTS: Of the 5,549 thyroid FNAC cases, 1,891 cases underwent surgical resection. In final diagnosis, 1,700 cases were revealed as papillary thyroid carcinoma (PTC), and 25 cases were reclassified as NIFTP. The cytologic diagnoses of NIFTP were non-diagnostic in one, benign in five, atypia of undetermined significance (AUS) in 14, follicular neoplasm in two, and suspicious for malignancy in three cases. Collectively, NIFTP/encapsulated follicular variant of PTC (EFVPTC) were more frequently classified as benign, AUS, or follicular neoplasm and less frequently categorized as malignant compared to conventional PTCs. Exclusion of NIFTP from malignant diagnoses resulted in a slight decrease in malignancy rates in non-diagnostic, benign, AUS, follicular neoplasm, and suspicious for malignancy categories without any statistical significance. CONCLUSIONS: The decrease in the ROM was not significant when NIFTP was excluded from malignant lesions. In thyroid FNACs, NIFTP/EFVPTCs were mostly classified into indeterminate categories. Therefore, it might be feasible to separate NIFTP/EFVPTC from conventional PTC on FNAC to guide clinicians to conservative management for patients with NIFTP/EFVPTC.

Role of pro-angiogenic marker galectin-3 in follicular neoplasms of thyroid.

The role of pro-angiogenic marker galectin-3 (GAL-3) was examined in differential diagnosis of follicular neoplasms of thyroid into histological subsets of follicular adenoma (FA), follicular carcinoma (FC) and follicular variant of papillary thyroid carcinoma (FVPTC). The study included 22 cases from January 2006 to June 2011 comprising of FA (n = 12), FC (n = 3) and FVPTC (n = 7). Immunohistochemical evaluation of GAL-3 was performed on representative histologic sections from the resected thyroid specimens. The proportion of stained cells and intensity of staining in tumor blood vessels were evaluated. GAL-3 expression showed that angiogenesis was prominent in malignancy (FC and FVPTC) and negative in non-neoplastic thyroid parenchyma and benign condition (FA). GAL-3 expression was found to differentiate benign from malignant follicular neoplasms. Focal and diffuse positivity for GAL-3 was found to be associated with FC and FVPTC respectively, thus GAL-3 can be used as a immunohistochemical marker in the differential diagnosis of follicular neoplasms of thyroid based on the type of expression. Limitation of this study was relatively less number of cases studied; however, this data need to be corroborated in larger cohort.

Follicular Variant of Papillary Thyroid Carcinoma: Clinical Manifestation and Prognosis / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Despite relatively high incidences of follicular variant of papillary thyroid carcinoma (FV-PTC), there is a continuous debate regarding the clinical behavior, treatment outcome, prognostic variables and survival of this disease. We performed this study for the purpose of getting further understanding and more supporting ideas for the treatment of FV-PTC. SUBJECTS AND METHOD: A clinicopathologic analysis of 116 patients who underwent a thyroidectomy with a final diagnosis of FV-PTC divided the patients into three groups: the FV-PTC only group (group A, n=78), the FV-PTC group who developed classical papillary thyroid carcinoma (C-PTC) (group B, n=38) and the C-PTC only (group C, n=320, 2003, Korea Cancer Center Hospital). The three groups were compared with respect to the following various clinicopathological characteristics: age at diagnosis, tumor size, stage of tumor, capsular invasion, age, metastasis, extent, size score, multifocality of tumor, LN metastasis, treatment, and recurrence. RESULTS: The mean tumor sizes, disease stage, and type of initial surgery were similar in three groups. However, the prevalence of nodal disease and capsular invasion were significantly higher in the groups B and C compared to the patients of group A. The 8-year disease-free survival rate was 93.7% in the patients with FV-PTC only, 90.4% in the patients with C-PTC only and 88.2% in the patients with FV-PTC group, who developed C-PTC (p>0.05). CONCLUSION: The clinical behavior and prognosis of PTC and FV-PTC groups did not differ significantly. In treating FV-PTC, we find that it is desirable to choose a similar strategy as that used to treat C-PTC.

The Diagnostic Accuracy of Fine Needle Aspiration Cytology and the Diagnostic Usefulness of Galectin-3 Immunostaining for the Follicular Variant of Papillary Thyroid Carcinoma / 대한세포병리학회지

The cytologic diagnosis of the follicular variant of papillary thyroid carcinoma (FVPTC) has become one of the common causes of false negative diagnoses when performing fine needle aspiration cytology (FNAC) of the thyroid gland. We retrospectively reviewed all the aspirates for which a diagnosis of FVPTC had been made based on the surgically excised specimens, regardless of the cytologic diagnosis. 145 FNACs was performed in 135 patients. The cytologic diagnoses were categorized as 2 unsatisfactory specimens (1.4%), 16 benign (11.0%), 49 atypical (33.8%) and 78 malignant lesions (53.8%). The tumor cells consistently showed significant nuclear overlapping, irregular nuclei and fine chromatin in all cases; however, nuclear grooves and inclusions were scarce. Galectin-3 immunostaining was performed on the cell blocks of 65 cases and this was positive for 45 cases (69.2%). The results of our study demonstrate that the determination of minimal cytologic criteria is needed to raise the sensitivity of detecting FVPTC by FNAC, and galectin-3 immunostaining is useful to make decisions on the surgical treatment of cytologically atypical thyroid nodules.