Clinical-Pathological and Molecular Evaluation of 451 NIFTP Patients from a Single Referral Center

Background: Non-invasive follicular thyroid neoplasms with papillary-like nuclear features (NIFTPs) were introduced in thyroid pathology in 2016. NIFTPs are a group of follicular neoplasm with an indolent behaviour. In this study, we gathered a large retrospective cohort of NIFTPs and compared those presenting as solitary lesions and NIFTPs found in multifocal setting. Methods: A retrospective search of NIFTPs was performed, and the clinico-pathological features were recorded. For a subgroup of patients, pre-surgical ultrasound (US) evaluation, cytological diagnosis, and molecular analysis were available. Results: We collected 451 NIFTPs; 254 (56.3%) were truly solitary tumours, while 197 coexisted with one or more NIFTP/cancer. Contrasting unifocal and multifocal settings, NIFTPs size was the only significantly different parameter. Preoperatively, NIFTP nodules mostly showed low-risk US characteristics, indeterminate cytology and a RAS-like molecular profile. Conclusion: NIFTPs often coexist with collateral thyroid tumours. However, no clinical-pathological differences can be observed between solitary and “multifocal” NIFTPs. Despite the well-established clinical indolence of NIFTP, a careful monitoring of the contralateral lobe should not be excluded.

Rate and Clinical Predictors of Malignancy in Thyroid Nodules with Indeterminate Cytology

Background: Fine needle aspiration cytology (FNAC) cannot differentiate between benign and malignant conditions in cytologically indeterminate thyroid lesions. Therefore, a minimum of diagnostic lobectomy is required for definitive diagnosis. The objective of this study is to identify the rate of malignancy and clinical features that may possibly predict malignancy in patients with these lesions, in Ethiopian hospitals. Methods: This was a retrospective review of the medical records of patients who underwent surgery for cytologically indeterminate thyroid lesions in three referral hospitals between September 2015 and September 2020. Results: Of 85 patients with indeterminate cytology findings, 56 (63.5%) were follicular, and 29 (34.1%) were reported to be hurthle cell neoplasms. Follicular lesions of undetermined significance (FLUS) and suspicious for follicular neoplasm were each reported in single cases (1.7%). Malignant disease was diagnosed in 19 (22.4%) of patients. A follicular variant of papillary cancer was detected in 7 (11.5%) patients. Hard nodule consistency was reported in 9 of 11 malignant lesions and 5 of 66 benign lesions. In multivariate binary logistic regression, hard nodule consistency was found to be associated with malignancy (P = 0.012, AOR = 7.28 (1.5, 34.54) 95% CI ). The ill-defined surface of a nodule was found to be associated with malignancy though the association was not statistically significant (P = 0.088, AOR = 0.162 (0.020, 1.313) 95% CI. Ultrasound evaluation of thyroid nodule was performed only in 41 (47.7%) of patients. Conclusion: The rate of malignancy in thyroid nodules with indeterminate cytology was 22.4%. The risk of malignancy was higher in patients with hard thyroid nodule consistency and ill-defined surface. Despite the established benefits of ultrasound for the evaluation of thyroid nodules, the current practice of its use in our setup is suboptimal. Keywords: Follicular; hurthle cell; indeterminate cytology; predictors of malignancy

Thyroid cytology during the COVID-19 pandemic: a single centre experience

Background: In our study, thyroid fine-needle aspiration biopsy (FNAB) data in the same calendar period of 1 year before and after the COVID-19 pandemic were compared.Methods: Thyroid FNAB data for the same calendar period of 1 year before and after the COVID-19 pandemic were included in the study. The patients were grouped according to age, gender and thyroid FNABs according to the Bethesda system for reporting thyroid cytopathology, and the data of both groups were compared considering the diagnoses of the patients who underwent thyroid surgery afterwards.Results: In the post-pandemic period, the number of thyroid FNABs and the number of patients over the age of 40 decreased (all p<0.001). In the post-pandemic period, the rates of atypia of undetermined significance or follicular lesion of undetermined significance (AUS/FLUS), follicular neoplasm or suspicious for a follicular neoplasm (FN/SFN), suspicious for malignancy, and malignant cytology increased despite the decrease in the number of patients (p=0.001). Furthermore, the malignant tumour rate was 1.4% before the pandemic in patients who underwent surgical thyroidectomy and/or lobectomy; this rate was 3.5% in the post-pandemic period (p=0.045).Conclusions: We found an increase in the percentage of AUS/FLUS, FN/SFN, suspicious for malignancy, and malignant cases during the period when there were restrictions, such as pandemics, and the sampling was reduced. This finding is valuable in terms of detecting an increased malignancy rate by performing less thyroid FNAB by carefully determining the indications for thyroid aspiration biopsy regarding the latest guidelines.

The Utility of Serum Anti-thyroglobulin Antibody and Thyroglobulin in the Preoperative Differential Diagnosis of Thyroid Follicular Neoplasm

PurposeIt is challenging to distinguish follicular thyroid carcinoma (FTC) from follicular thyroid adenoma (FTA) before surgery due to the lack of malignant ultrasound features, the underdiagnosis by fine-needle biopsy, and the absence of definitive markers. We investigated whether thyroglobulin (Tg), anti-thyroglobulin antibody (TgAb), thyroid peroxidase antibodies (TPOAb), and thyroid stimulating hormone (TSH) could help differentiate FTC from FTA.MethodsA total of 319 patients with follicular neoplasms were included. We analyzed the serum markers as continuous and categorical variables between FTC and FTA. Also, we analyzed the prevalence of FTC in different serum markers groups.ResultsThe TgAb was a risk factor of FTC. Versus the TgAb group (≤11.68 IU/mL), OR of the group (11.69-30.50 IU/mL) and the group (＞30.50 IU/mL) were 2.206 (1.114-4.369, P=0.023) and 3.247 (1.684-6.260, P＜0.001), respectively. Versus the TgAb group (≤11.68 IU/mL), the malignant prevalence of the group (＞30.50 IU/mL) was higher (13.1% vs. 32.9%, P=0.001). In TgAb (-) patients, the Tg was another risk factor of FTC. Versus the Tg group (≤38.51 ng/mL), OR of the group (＞434.60 ng/mL) was 3.836 (1.625-9.058, P=0.002); the malignant prevalence of the group (＞434.60 ng/mL) was 47.2% and higher than other groups.ConclusionsThe TgAb and Tg may have utility in the preoperative differential diagnosis of follicular neoplasm. The higher TgAb and Tg were associated with higher malignant risk. Thus, we should be cautious of preoperative TgAb and Tg in follicular neoplasm.

Pilot imaging study of o-BMVC foci for discrimination of indeterminate cytology in diagnosing fine-needle aspiration of thyroid nodules

Fluorescence lifetime imaging microscopy of a fluorescence probe, 3,6-bis(1-methyl-2-vinylpyridinium) carbazole diiodide (o-BMVC), provides an objective method for preoperative diagnosis of fine-needle aspiration (FNA) of thyroid nodules. The key of this o-BMVC test of FNA smears is the measurement of the digital number of o-BMVC foci in the nucleus. Thus, there are three categories classified in the o-BMVC test, which are nondiagnostic for unsatisfactory samples, benign for less numbers of o-BMVC foci, and malignant for more numbers of o-BMVC foci. The discrimination of indeterminate (including atypia, follicular neoplasm, suspicious) cytology into benign or malignant cases can reduce diagnostic uncertainty and benefit clinical decision making. This pilot study strongly suggests that the o-BMVC test is an invaluable method for diagnosing FNA samples. Particularly, the combination of FNA cytology and the o-BMVC test holds great promise to improve the efficacy of diagnosis and reduce the healthcare costs.

Comparison of Diagnostic Rates and Concordance with Subsequent Surgical Resections between Conventional Smear and ThinPrep Preparations versus ThinPrep Only in Thyroid Fine Needle Aspiration (T-FNA) Specimens

<b><i>Background:</i></b> Thyroid fine needle aspiration (T-FNA) is a mainstay in management of thyroid nodules. However, the preparation of T-FNA specimens varies across institutions. Prior studies have compared diagnostic rates between different specimen preparations of T-FNA specimens and their associated advantages and disadvantages. However, few have compared the rates of all diagnostic categories of The Bethesda System for Reporting Thyroid Cytopathology (TBSRTC) between liquid-based preparations (LBPs) and a combination of LBP and conventional smear (CS) preparations. Our study compares TBSRTC diagnostic rates between these 2 cohorts and correlates cytologic diagnoses with subsequent thyroid resections to evaluate rates of neoplasia (RON) and malignancy (ROM). <b><i>Methods:</i></b> 584 consecutive thyroid FNA specimens were collected and stratified by preparation type (ThinPrep [TP] vs. CS &amp; TP). Diagnostic rates for each TBSRTC diagnostic category were calculated. The institution’s electronic medical records database was searched for histologic diagnoses of previously sampled thyroid nodules to evaluate the RON and ROM. <b><i>Results:</i></b> Of 584 thyroid FNA specimens, 73 (12.5%) and 511 (87.5%) were evaluated by TP only and CS &amp; TP, respectively, reflecting the predominance of rapid on-site evaluation (ROSE) with CS for T-FNAs at our institution. Of the TP only and CS &amp; TP cohorts, 29 (39.7%) and 98 (19.2%) had subsequent resections, respectively. The frequency of non-diagnostic cases was lower in the CS &amp; TP cohort (12.7% vs. 26%). While the diagnostic rate of follicular lesion of undetermined significance was similar for both cohorts, SFN categorization was only utilized in the CS &amp; TP cohort (1.5% vs. 0%). Although RON and ROM were similar between cohorts in many of the TBSRTC categories, there was a higher RON associated with non-diagnostic specimens in the TP only cohort when the denominator included all non-diagnostic cases. <b><i>Conclusion:</i></b> The combination of CS and LBP may potentially decrease the non-diagnostic rate of T-FNA specimens as well as the number of passes required for diagnosis, particularly with ROSE. Evaluation of morphologic features highlighted in conventional smears may facilitate diagnostic categorization in the “suspicious for follicular neoplasm” category.

Diagnostic Accuracy of Fine Needle Aspiration Cytology in Thyroid Nodules in Thammasat University Hospital

Background: Fine needle aspiration (FNA) cytology is a key investigation of thyroid nodules. There are several reports of FNA accuracy, which ranges from 75.0% to 94.8%, while false negative rates are 5.8% to 21.5%. In Thailand, there is no available data of FNA accuracy according to the Bethesda System for Reporting Thyroid Cytopathology (TBSRTC). The present study reported single-institute data of FNA accuracy, that could be used in thyroid nodule management. Objective: To determine the diagnostic accuracy of FNA cytology results of thyroid nodules collected in Thammasat University (TU) Hospital. Materials and Methods: The present study was a retrospective study collected cytologic results of all thyroid nodules that subsequently had definitive histopathologic diagnoses. The data were gathered from clinics at TU Hospital that performed thyroid nodule FNA between May 2011 and November 2014. The FNA cytology results were classified according to TBSRTC. Each cytopathologic result was compared with its postoperative tissue histopathology. The malignancy rate, sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy were calculated. Results: The present study included 197 thyroid nodule FNA cytology results. The sensitivity and specificity were 77.8% and 65.4%, respectively. The calculated PPV was found to be 47.7%, and the NPV was 87.9%. The accuracy of these results was 69.0%. The malignancy rate of the unsatisfactory group was 6.25%, benign group 8.05%, atypia of undetermined significance or follicular lesion of unknown significance 22.22%, follicular neoplasm/suspicious for follicular neoplasm 14.20%, suspicious for malignancy 73.68%, and malignant 100%. Conclusion: The FNA cytology in TU Hospital has comparable sensitivity to the other studies. Interestingly, the malignancy rate in the follicular neoplasm category is lower than that of the other institutes because of a high false positive rate in this category. This causes lower specificity and accuracy, which may cause a higher rate of unnecessary operations. Keywords: FNA; Thyroid nodule; Diagnostic accuracy