Role of fine-needle aspiration cytology in evaluating thyroid nodules. A retrospective study from a tertiary care center of Western region, Saudi Arabia

Efficacy of Follicular Cell Pattern Analysis in Thyroid Fine-needle Aspiration Cytology Evaluation

CONTEXT

Fine-needle aspiration cytology (FNAC) is widely utilized for thyroid lesion diagnosis but faces challenges such as sample inadequacy and overlapping cytological features. This study examines how accurately these patterns correlate with histopathological diagnoses, shedding light on FNAC's limitations and diagnostic potential.

AIMS

To study the application of the architectural pattern of follicular cells in the interpretation of thyroid lesions and to demonstrate the diagnostic accuracy (DA) of FNAC.

SETTINGS AND DESIGN

Cross-sectional study carried over 1 year.

SUBJECTS AND METHODS

A total of 110 cases were reviewed by the cytopathologists. The prominent follicular cell architecture, namely macrofollicular, microfollicular, papillary, trabecular, three-dimensional clusters, and dispersed cells, was described in each case. In addition to these patterns, cellular morphology and background features were also noted, and a final cytological diagnosis was established. The cytology diagnosis was correlated with the histopathological diagnosis.

STATISTICAL ANALYSIS USED

Sensitivity, specificity, positive predictive value, negative predictive value, DA of FNAC in diagnosing nonneoplastic and neoplastic lesions.

RESULTS

Macrofollicular pattern was seen in 80.26% of colloid goiter cases. Microfollicular pattern was observed in 72.2% of follicular neoplasm. About 62.5% of papillary thyroid carcinomas showed a papillary pattern. The trabecular pattern was seen in 42.86% of chronic lymphocytic thyroiditis and 16.67% of follicular neoplasms. The sensitivity and specificity of FNAC in diagnosing neoplastic lesions was 92.59% and 97.59%, respectively.

CONCLUSIONS

FNAC is a simple, rapid, definite, and cost-effective primary diagnostic tool for thyroid evaluation. Cell architecture pattern is a simple and appropriate approach that complements cell morphology and background details in arriving at the final cytological diagnosis of thyroid lesions.

Visualizing thyroid health: a pictorial journey through 2017 ACR TI-RADS and common thyroid pathologies

With the advent of high-resolution ultrasonography (HRUS), more thyroid nodules are being detected than ever before, and they are being identified at an earlier stage. It poses a challenge for radiologists and clinicians in deciding what to do next. Most nodules are benign and require no follow-up and intervention. Even highly suspicious nodules can be followed up, if the size is small. Variations in HRUS interpretation among radiologists are common, with frequent misidentifications between spongiform and solid-cystic lesions, hypoechoic and very hypoechoic nodules, and microcalcification and hyperechoic foci with comet-tail artifacts. Cystic lesions with echogenic contents are often confused with solid nodules, cystic papillary carcinoma thyroid is often confused with colloid cysts. The 2017 ACR TI-RADS (American College of Radiology Thyroid Imaging Reporting and Data System) aims to standardize the interpretation of thyroid nodules and guide further management. Rather than giving specific diagnosis like colloid cyst, adenomatous nodule and papillary carcinoma; ACR TI-RADS classifies nodules from TI-RADS 1 to TI-RADS 5 based on HRUS characteristics and recommends further management. What the authors often read are textual contents that are theoretical, and in practice, the authors get confused while interpreting the characteristics of thyroid nodules. This review offers a detailed visual overview of the 2017 ACR TI-RADS and common thyroid conditions, explaining key features through imaging data and examples for consistent interpretation. Combining textual explanations with visual aids, this article provides practical guidance for interpreting thyroid nodules for radiologists, and clinicians seeking a clear understanding of thyroid imaging and pathology.

A Cytohistologic Correlation Study of Thyroid Lesions: Evaluation of Diagnostic Accuracy and Pitfalls of Fine Needle Aspiration Cytology

Background Only about 5% of palpable thyroid nodules are malignant; the rest are entirely benign. In order to reduce the number of unnecessary treatments and properly identify situations that need surgical intervention, it is essential to distinguish between benign and malignant lesions prior to surgery. There exists a "grey zone" in thyroid cytology characterized by a significant decrease in diagnostic accuracy, making it difficult to precisely classify the lesion and leading to discrepancies. Aims and objectives The study aims to accomplish the following objectives: (1) assess the prevalence of thyroid lesions according to age and sex; (2) evaluate the accuracy of the fine needle aspiration cytology (FNAC) in diagnosing thyroid conditions; and (3) investigate the causes of cytohistological discordance within the context of this study. Materials and methods In our five-year study of thyroid lesions, 125 cases were studied for cytohistological correlation. Discrepant and likened FNAs were classified according to the diagnostic findings. A review of the cytological smears and histological sections was conducted. Results The cytological diagnoses were correlated with histopathology in 109 cases (90.83%). A total of 11 cases (09.16%) were discrepant. There were no false positives (FPs). The causes of false negative (FN) diagnoses in our study can be attributed to geographic misses and failure to recognize dual pathologies. Conclusion FNA is a very precise and time-saving technique for the diagnosis and subsequent management of palpable thyroid nodules. Patients having thyroidectomies have a much higher malignant yield, and the frequency of procedures performed on the thyroid is decreased. When FNA interpretation based on strict specimen sufficiency standards is considered along with clinical and imaging findings, the occurrence of FN and FP diagnoses is expected to decrease.

Comparative study of fine needle aspiration cytology and histopathology in thyroid nodules at a tertiary care hospital: First report from Somalia

BACKGROUND

FNAC is a minimally invasive procedure and cost-effective, especially in developing countries where patients are mostly poor and surgery is not affordable. The present is the first study that examines the correlation between FNAC and histopathology in diagnosing thyroid cancers at a tertiary hospital in Somalia.

METHOD

This study included 231 patients with thyroid lesions who underwent pre-operative FNACs and histopathologic examination over five years. Investigated clinical parameters include sociodemographic and clinical features and cyto-histopathological findings.

RESULTS

The mean patient age was 39.3 ± 15.5 years, and there was a significant female predominance (n = 194; 84%), with a female to male ratio of 5.2:1. The overall sensitivity, specificity, and accuracy rate of cyto-histopathology correlation was 91.1%, 96.6%, and 94.9%, respectively. According to the Bethesda classification system of thyroid FNACs, (n = 141, 61%) of cases were Bethesda II (Benign), of which 95.7% of patients had a benign final histological diagnosis, while 4.3% had malignancy (6 false-negative results). Twenty-two patients (9.5%) were Bethesda III, (n = 3,1.3%) were Bethesda IV (suspicious for neoplasm), and all cases had a follicular adenoma on their final histological diagnosis. Forty-four of the patients were Bethesda V, found in 88.6% of its final histological diagnosis, while 11.4% were benign. Bethesda IV accounted for 9.1%, and all patients in this group were papillary thyroid carcinoma on its final histological confirmation.

CONCLUSION

Our study findings revealed that FNAC of thyroid lesions has a high accuracy rate, sensitivity, and specificity, allowing appropriate initial diagnostic management. It should be applied as the first investigative tool for thyroid lesions.

B-mode Ultrasound Characteristics of Thyroid Nodules With High-Benign Probability and Nodules With Risk of Malignancy

INTRODUCTION

Thyroid nodules are commonly found on clinical examination or diagnostic imaging of the neck. Malignant thyroid nodules are increasing worldwide, making thyroid cancer one of the most common endocrine malignancies worldwide. The aim of this study was to determine B-mode ultrasound characteristics of benign thyroid nodules and nodules with risk of malignancy.  Material and methods: This retrospective study was conducted on subjects (n=99) who underwent thyroid ultrasound. Data were retrieved from the Thyroid Digital Image Database of Universidad Nacional de Colombia, a published open-access dataset, in which B-mode ultrasound images were interpreted by expert radiologists providing a complete diagnostic description of thyroid lesions using the Thyroid Imaging Reporting and Data System.

RESULTS

Sponge-like appearance (Pearson Chi-Square 4.6, p=0.02), cystic (Pearson Chi-Square 27.3, p<0.001), isoechoic (Pearson Chi-Square 26, p<0.001), and well-defined (Pearson Chi-Square 13.7, p<0.001) thyroid nodules were more likely to be observed in benign nodules (risk of malignancy <5%). On the other hand, predominately solid (Pearson Chi-Square 5.9, p=0.01), microcalcifications (Pearson Chi-Square 50.7, p<0.001), hypoechoic (Pearson Chi-Square 27.7, p<0.001), irregular shape (Pearson Chi-Square 6.6, p=0.01), and ill-defined (Pearson Chi-Square 8.8, p=0.003) thyroid nodules were more likely to be observed in nodules with risk of malignancy (>5%).

CONCLUSION

Ultrasound characteristics could be used to determine thyroid nodules with risk of malignancy and avoid over-diagnosing nodules with benign features. Further research evaluating the use of multiparametric ultrasound to distinguish between benign thyroid nodules and thyroid nodules with risk of malignancy is required.

Incidence and Malignancy Rates in Thyroid Nodules in North-East Indian Population by Bethesda System: A Single Institutional Experience of 3 Years

Suvamoy ChakrabortyIntroduction  Goiter is one of the most common conditions encountered clinically (up to 60% of population) with thyroid malignancy being one of the most common endocrine malignancies. The American Thyroid Association has advocated the need for validation of the Bethesda system of fine needle aspiration cytology (FNAC) in each center. The risk of malignancy (ROM) for Bethesda categories in the Indian population is limited. Objective  As there are variations in the effectiveness of FNAC, this study aims to study the role of FNAC in evaluating thyroid nodules, estimating the risk of malignancy in thyroid nodules in the North-East Indian population, and correlating the FNAC findings with HPE (histopathological examination). Materials and Methods  A total of 110 patients with thyroid nodules had visited the Department of Otorhinolaryngology during 2017-2020. Case records were retrieved, out of which only 66 patients had both FNAC and HPE reports. The FNAC of 66 patients were studied. Statistical Analysis  Data were analyzed using STATA V14. Fischer's exact test was used to determine the association of Bethesda system in diagnosing thyroid malignancy. The percentage agreement between the FNAC and HPE was calculated using the Kappa statistics. The diagnostic validity of FNAC in the diagnosis of malignant thyroid nodule was reported. Results  The sensitivity, specificity, PPV, and NPV of FNAC in diagnosing thyroid malignancy were 52%, 94.3%, 89%, and 69% respectively. The risk of malignancy (ROM) for Bethesda I to VI categories in our study was 20%, 25%, 67%, 40%, 78%, and 100% respectively ( p -value < 0.001, Fischer's exact test). Conclusion  A specificity of 94.3% and PPV of 89% of FNAC makes it a good reliable tool in ruling in malignancy in our population. The higher ROM in indeterminate categories necessitates the need to consider thyroidectomy with or without intraoperative frozen section analysis in our population. Similar higher ROM has been reported in a few other Indian studies. These findings may suggest an increased ROM for Bethesda categories III and IV in the Indian population; however, the statement needs further validation from large multicentric studies with research to find the reason for the increased risk.

The impact of thyroid imaging reporting and data system on the management of Bethesda III thyroid nodules

Objectives

Atypia of undetermined significance (AUS) or follicular lesion of undetermined significance (FLUS) is a heterogeneous category of fine needle aspiration cytology (FNAC); the management of this condition remains controversial. The clinical significance of such patients relies on the exclusion of malignancy. In this study, we aimed to determine the validity of the American College of Radiology Thyroid Imaging Reporting and Data System (ACR TI-RADS) (2017) for predicting malignancy in this specific category of patients.

Methods

In this study, we analysed a cohort of patients from our previous retrospective study. This four-year retrospective cohort study included all cases undergoing surgery with a cytological diagnosis of AUS/FLUS. We enrolled 110 cases with documented final histopathological diagnoses and ultrasound examinations.

Results

The study included 83 females (75.5%) and 27 males (24.5%). The overall risk of malignancy (ROM) for AUS/FLUS thyroid nodules was 47.3%. The ROMs of TI-RADS 3 (TR3), TI-RADS 4 (TR4), and TI-RADS 5 (TR5) were 43.5%, 49.4% and 40%, respectively. There was no significant association between TI-RADS and final pathological analysis.

Conclusions

Repeated FNAC with initial AUS/FLUS nodules is crucial. Our findings showed that ACR TI-RADS did not contribute to the cancer risk stratification of AUS/FLUS nodules. A large prospective multi-institutional study is now required to determine the validity of ACR TI-RADS and whether other adjunct clinical, cytological, molecular, or biochemical tools could facilitate the management of patients with these heterogeneous nodules.

The Value of Ultrasonography Using Thyroid Imaging Reporting and Data Systems (TIRADS) in the Diagnosis of Thyroid Cancer Among the Population of Ha'il, Saudi Arabia

Background: Thyroid cancer is one of the common malignant conditions of the head and neck region, and it is considered as one of the most common cancers among endocrine tumors. Ultrasonography is widely used in order to assess thyroid nodules, Therefore, the aim of our study is to determine the accuracy of ultrasonography and fine needle aspiration biopsy (FNAB)-guided by ultrasonography in the diagnosis of thyroid malignancy among the population in the Ha'il region of Saudi Arabia.

Methods: A retrospective evaluation of 137 patients was undertaken at King Salman Specialist Hospital, Ha'il, Kingdom of Saudi Arabia. Patients who presented with thyroid swellings underwent ultrasonography and FNAB.

Result: Our study results have concluded that the sensitivity of the ultrasonography in the confirmation of a malignant thyroid lesion is 59.4% and its specificity was found to be 74.3%.

Conclusion: The study showed that ultrasonography using Thyroid Imaging Reporting and Data Systems (TIRADS) is a significant step in evaluating a thyroid nodule. Also, it is highly sensitive and specific, cost-effective, and convenient for the patient.

Molecular Testing of Atypical Thyroid Nodules with Corresponding Surgical Correlation: Five-Year Retrospective Review in Veterans Population

Objective

We report the results of a retrospective five-year study within a veteran population aimed at correlating abnormal thyroid fine-needle aspiration (FNA) diagnosis with associated molecular testing to the histology of the surgical resection.

Methods

A retrospective analysis of abnormal thyroid FNAs with associated molecular testing and surgical outcome was conducted from January 1, 2015 to December 31, 2020. Aspirates were classified using the Bethesda system for reporting thyroid cytopathology, including atypia of undetermined significance/follicular lesion of undetermined significance (AUS/FLUS), follicular neoplasm/suspicious for follicular neoplasm (FN/SFN), suspicious for malignancy (SM), and malignant. Pertinent data, including patient demographics, imaging, and ancillary testing were reviewed. A thyroid cancer mutation panel assessing the most common mutations and rearrangements associated with neoplasia was utilized. The results of molecular testing were directly compared and correlated with final cytological and histological diagnosis.

Results

A total of 1850 thyroid aspirates were performed, 200 of which were given an abnormal cytologic diagnosis. Thirty-six samples were submitted for molecular testing and subsequent surgical follow-up. Four were called malignant on cytology. 32 were placed in an indeterminate category (89%). Within indeterminate cases: 53% exhibited positive molecular mutations (n=17), 34% no mutation detected (n=11), and 13% insufficient quantity for testing (n=4). Upon surgical resection in the mutation-positive group: 18% had no malignancy (n=3), and the remaining 82% were positive for malignancy (n=14). Mutations in the histologically malignant group included: 57% BRAF (n=8), 21% NRAS (n=3), 7% HRAS (n=1), 7% KRAS (n=1), and 7% PAX8/PPAR gamma (n=1). In indeterminate cases with no mutation detected, 10 cases were found to be benign, and one case of malignancy was diagnosed. The probability of indeterminate diagnosis in combination with no mutation yielded a 91% chance of benign entity and 9% chance of malignancy. We demonstrated 93% sensitivity and 91% negative predictive value (NPV) for the risk of malignancy in indeterminate cytology specimens with ancillary molecular testing. There was 77% specificity and 82% positive predictive value (PPV) for our data set.

Conclusions

In indeterminate samples, the detection of a mutation was highly predictive of malignancy and a strong indicating factor for surgery with a high sensitivity and NPV. Molecular testing refined or established the diagnosis in 89% of the cases. Our results indicate that molecular testing of thyroid nodules enhances the accuracy of FNA cytology and the subsequent surgical outcome.

Diagnostic Reliability of the American College of Radiology Thyroid Imaging Reporting and Data System in Royal Commission Hospital, Kingdom of Saudi Arabia

BACKGROUND: The American College of Radiology Thyroid Imaging Reporting and Data System (ACR TI-RADS) classified and predicted the risk of thyroid nodule malignancy with ultrasound scan scoring system. AIM: Hence, we aimed to investigate the value of the combined use of ultrasound ACR TI-RADS scoring and ultrasound-guided thyroid fine needle aspiration cytology (FNAC) based on the Bethesda System for Reporting Thyroid Cytology (TBSRTC) for assessing the accuracy tests of diagnosing low and high-risk thyroid nodules of ACR TI-RADS. METHODS: We enrolled 392 patients with thyroid nodules who underwent ultrasound scanning and scoring using the ACR TI-RADS classification along with ultrasound-guided thyroid FNAC and scoring with TBSRTC. The two methods were grouped as low and high risk of malignancy to evaluate the accuracy of ACR TI-RADS. RESULTS: Three hundred and ninety-two patients were enrolled in the study. The mean (Standard deviation [SD]) age was 46.03 (13.96) years, 332 (84.7%) were females and the mean (SD) of body mass index was 31.90 (22.32) kg/m2 and Vitamin D 17.65 (11.15) nmol/L. The mean (SD) for thyroid function test was 5.37 (44.16) mmol/L for thyroid-stimulating hormone, 1.48 (1.49) ng/dL for free thyroxine (FT4), and 2.69 (0.70) nmol/L for free triiodothyronine (FT3). Most of the participants were euthyroid (63.8%), but 28.6% had hypothyroidism and 7.7% had hyperthyroidism. The accuracy tests of ACR TI-RADS in relation to TBSRTC, were sensitivity (87.8%), specificity (65.2%), positive predictive value (29.8%), and negative predictive value (97%). The area under the curve = 0.590, 95% CI = 0.530–0.650, p ˂ 0.006. CONCLUSION: ACR TI-RADS is a simple, practical, and reliable scoring system for assessing thyroid nodule; it has a better overall diagnostic performance and the ability to exclude unnecessary FNAC with high negative predictive value.

The prevalence and associated predictors for Bethesda III-VI for reporting thyroid cytopathology in Royal Commission Hospital, Kingdom of Saudi Arabia

BACKGROUND

Thyroid cancer is increasing globally and is currently the most prevalent endocrine malignancy. Recent data show an increase in the incidence of thyroid cancer in the Kingdom of Saudi Arabia (KSA). Thyroid ultrasound and fine-needle aspiration cytology (FNAC) are the cornerstones in managing thyroid nodules. We conducted this study to evaluate the prevalence and the associated predictors for thyroid nodule Bethesda III-VI in eastern KSA.

METHODS

A retrospective study was conducted between January 2015 and 31 August 2021. The participants were recruited patients who received a thyroid ultrasound and ultrasound-guided thyroid FNAC, using the thyroid imaging reporting and data system (TI-RADS) and the Bethesda Classification, respectively.

RESULT

Three hundred and ten patients who underwent thyroid FNAC were enrolled in the study. The median (interquartile, IQR) age was 47.0 (20.0) years, and 266 (85.8%) of them were females. The median (IQR) body mass index was 30.2 (7.6) kg/m². Out of these participants, 64.8% were euthyroid, 27.4% had hypothyroidism and 7.7% had hyperthyroidism. The ACR TI-RADS-3, 4 and 5 were 51.3%, 46.1% and 2.6%, respectively. The Bethesda outcome of thyroid FNAC I-VI was 5.2%, 63.9%, 15.5%, 5.8%, 3.5% and 6.1%, respectively. The risk for malignancy (Bethesda III-VI) was documented in 31.0% and atypia of undetermined significance was most prevalent (15.5%). A higher ACR TI-RADS score was associated with a higher risk of malignancy: ACR TI-RADS-3 (20.8%), ACR TI-RADS-4 (39.2%) and ACR TI-RADS-5 (87.5%). In a multivariate analysis, only the ACR TI-RADS score was significantly associated with the outcome of thyroid FNAC: ACR TI-RADS-4 [OR = 2.59 (95% CI = 1.54-4.36)] and ACR TI-RADS-5 [OR = 29.03 (95% CI = 3.44-245.07)].

CONCLUSION

There was a high prevalence of Bethesda III-VI and atypia of undetermined significance was most prevalent. A thyroid ultrasound report for TI-RADS was significantly associated with the outcome of thyroid FNAC and is a reliable tool in the absence of molecular testing for thyroid cancer.

Practice of thyroid nodule management in the Gulf Cooperation Council countries

OBJECTIVES

To assessed the current practices for the management of thyroid nodules in the Gulf Cooperation Council (GCC) countries. Methods: We conducted a descriptive web-based survey to physicians and surgeons involved in the management of thyroid nodules. The survey included questions on referral, ultrasound (US) reporting, fine needle aspiration (FNA), management of thyroid nodules including the approach for indeterminate FNA results, and usage of molecular testing. Results: A total of 311 responders, 155 (49.8%) were endocrinologists. Results showed that referrals and US report lack a number of valuable information including family history (84.9%) and high-risk US features (92.9%). Approximately 263 (84.6%) preferred to include a scoring system or protocol to assess the nodule risk in US report. Approximately 193 (62.1%) sent the patient to interventional radiologists for FNA. Almost half (n=147, 47.3%) repeat the FNA in 2-3 months if the FNA result was a follicular lesion or atypia of undetermined significance and 142 (45.7%) opted for lobectomy for follicular neoplasm or suspicious of follicular neoplasm result. Only 44 (14.1%) performed molecular testing; however, 174 (55.9%) preferred it available. Significant variations in the approach were seen between endocrinologists versus non-endocrinologists. Conclusion: Practices variation in the management of thyroid nodules mandate a common practical guideline. Molecular testing is a preferable test for indeterminate FNA results by most of the responders though it is not widely available.