Impact of fine needle aspiration cytology strategy implemented at the microscopy center level for diagnosis of tuberculous lymphadenitis.

INTRODUCTION: In India, EPTB accounts for about 50% of TB cases especially in people living with HIV/AIDS. Microbiological confirmation is present in only about 15% of EPTB cases. Tuberculous Lymphadenitis is the most common form of EPTB in India, accounting for around 35% of EPTB cases. Fine needle aspiration cytology has been found to be highly sensitive and specific in the diagnosis of tuberculous lymphadenitis with 83-94% accuracy. The procedure of AFB detection is exactly the same for the FNAC obtained smears as for the presently examined sputum smears at the DMCs. The aim of the present study was to determine the feasibility and effectiveness of FNAC strategy implemented at DMC level for detection of tuberculous lymphadenitis cases. METHODS: The present study was a randomized cluster trial with one control and one intervention arm. At the intervention units (DMCs) all suspected tuberculous lymphadenitis cases was subjected to FNAC of the suspected superficial lymph nodes by the trained Medical Officers. The control group was free from any such intervention. Effectiveness and feasibility of FNAC strategy in the intervention group was determined by relevant indicators. RESULTS: At the seven intervention DMCs, FNAC was performed on a total number of 1298 suspected cases of Tuberculous Lymphadenitis. Among them 294 cases were selected in the intervention arm and 196 cases in the control arm. Intervals between advice of FNAC and performance of FNAC as well as start of therapy was significantly low in the intervention arm. Complication was insignificant. The concordance between FNAC reports generated at the DMCs and that at Medical College estimated by agreement measurement kappa (0.970) suggested a high level of agreement. CONCLUSION: Implementation of FNAC strategy at the DMC level for detection of tuberculous lymphadenitis cases was found to be feasible as well as effective.

Thyroid Fine-Needle Aspiration: The Current and Future Landscape of Cytopathology.

Thyroid cytology is a rapidly evolving field that has seen significant advances in recent years. Its main goal is to accurately diagnose thyroid nodules, differentiate between benign and malignant lesions, and risk stratify nodules when a definitive diagnosis is not possible. The current landscape of thyroid cytology includes the use of fine-needle aspiration for the diagnosis of thyroid nodules with the use of uniform, tiered reporting systems such as the Bethesda System for Reporting Thyroid Cytopathology. In recent years, molecular testing has emerged as a reliable preoperative diagnostic tool that stratifies patients into different risk categories (low, intermediate, or high) with varying probabilities of malignancy and helps guide patient treatment.

Salivary Gland Fine-Needle Aspiration: The Current and Future Landscape.

Fine-needle aspiration represents a valid tool for the diagnosis/management of salivary gland lesions. The past years assessed the lack of uniform diagnostic reports for salivary cytopathology leading to interpretative issues. In 2015, an international group of cytopathologists developed an evidence-based tiered classification system for reporting salivary gland fine-needle aspiration (FNA) specimens, the "Milan System for Reporting Salivary Gland Cytopathology" (MSRSGC). The present landscape of salivary cytology is represented by the growing adoption of the MSRSGC and the assessment of its diagnostic role. The future landscape is characterized by the increasing role of ancillary techniques for diagnostic and prognostic purposes.

Pancreas Fine Needle Aspiration: Current and Future Impact on Patient Care.

Pancreatic lesions can be solid or cystic and comprise a wide range of benign, premalignant, and malignant entities. Endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) is the current primary sampling method for the preoperative diagnosis of pancreatic lesions. Optimal handling of cytology/small tissue specimens is critical to ensure that the often-scant diagnostic material is appropriately utilized for ancillary and/or molecular studies when appropriate. Ultimately, evaluation of EUS-FNA cytology and small biopsy material can provide accurate and timely diagnoses to guide patient management and triage them to surveillance or surgical intervention.

The Current and Future Impact of Lymph Node Fine-Needle Aspiration Cytology on Patient Care.

Lymph node (LN) fine-needle aspiration cytology (FNAC) is a common diagnostic procedure for lymphadenopathies. Despite the qualities and potentialities of LN-FNAC, the number of possible pathologies and the variety of clinical contexts represent a challenge and require a continuous upgrading of the procedure according to the emerging clinical requests and new technologies. This study presents an overview of the current and future impact of LN-FNAC on the care of patients with lymphadenopathy.

Predictive value of the single most suspicious ultrasound feature in subcentimeter thyroid nodules: a retrospective observational cohort study.

PURPOSE: Proper management of subcentimeter thyroid nodules remains challenging for both clinicians and patients. Conducting extensive sonographic research using a safe and inexpensive tool for identifying thyroid nodules is necessary. The aim of this study was to identify whether having the highest-risk ultrasound (US) characteristic suggests that US-guided fine-needle aspiration (FNA) biopsy of subcentimeter nodules is more appropriate for the identification of malignancy than active surveillance (AS) or surgery. METHODS: The data of patients with highly suspicious subcentimeter thyroid nodules and US characteristic data who underwent surgery were retrospectively examined. RESULTS: Among a total of 556 subcentimeter nodules, 223 (40.1%) were benign, and 333 (59.9%) were malignant, with a mean maximal nodule size of 8.1 mm. In addition to age younger than 45 years, several US features were significantly associated with malignancy: irregular margins, the presence of microcalcifications, and taller-than-wide shapes (P < 0.001). Multivariate analysis also revealed that a taller-than-wide shape (OR = 8.988, P = 0.0015) was an independent factor associated with malignancy in subcentimeter thyroid nodules. The diagnostic performance of preoperative FNA was classified as a malignancy, with a sensitivity of 98.4%, specificity of 100%, positive predictive value of 100%, and negative predictive value of 76.9%. CONCLUSIONS: This is one of the few reports based on actual data of the most suspicious US features in subcentimeter thyroid nodules. A taller-than-wide shape US feature is most significantly associated with malignancy. FNA is a simple, accurate, and reliable preoperative method for diagnosing malignant subcentimeter thyroid nodules with highly suspicious US characteristics. AS was less appropriate than FNA for subcentimeter nodules with a taller-than-wide shape, especially in patients ≤ 45 years of age.

SILICONE FINE-NEEDLE ASPIRATION RETINAL BIOPSY: A Novel Surgical Technique for Vitreoretinal Lymphoma.

PURPOSE: To describe a 41-gauge silicone fine-needle aspiration biopsy (S-FNAB) technique and assess its value in diagnosing primary vitreoretinal lymphoma (PVRL). METHODS: Retrospective review of seven consecutive patients who underwent vitreous biopsy (VB) and 41-gauge S-FNAB of retinal/subretinal lesions in a single tertiary center between January 2012 and March 2023. RESULTS: Of seven patients, S-FNAB confirmed the diagnosis of PVRL in six patients. In five of those patients, both VB and retinal/subretinal S-FNAB (performed at the same procedure) yielded positive results, with the retinal thickness at the biopsy site as small as 231 µm. Four of these five patients had one or more previous negative VB. In one patient, S-FNAB yielded positive results despite a negative VB. Silicone fine-needle aspiration biopsy failed to confirm positive VB for PVRL in the remaining patient. The time from symptom onset to diagnosis of PVRL ranged from 18 days to 26 months. There were no severe complications associated with the procedure. CONCLUSION: Silicone fine-needle aspiration biopsy might be a valuable method for obtaining a sufficient sample of viable cells to diagnose PVRL. It can be performed as a primary procedure along with VB. Further studies are warranted to determine where this technique could be most advantageous.

Study of Diagnostic Yield of Nucleic Acid Amplification Test among Tuberculous Cervical Lymphadenitis in Immunocompetent Patients.

BACKGROUND: The most common form of extrapulmonary tuberculosis (TB) is tuberculous lymphadenitis, which constitutes about 30-40% of all extrapulmonary TB cases. A new diagnostic method like the nucleic acid amplification test (NAAT) is a very sensitive and rapid test for diagnosing tuberculous cervical lymphadenopathy. It also detects rifampicin sensitivity among positive patients. OBJECTIVES: (1) To evaluate the diagnostic yield of TrueNAT for detecting Mycobacterium tuberculosis bacteria in the fine-needle aspirated samples of cervical lymph nodes compared with Ziehl-Neelsen (ZN) staining; (2) to evaluate the diagnostic yield of TrueNAT for diagnosis of tuberculosis through comparison with the cytology report of fine-needle aspiration (FNA) sample of cervical lymph node and with necrotic cervical lymph node on ultrasonography (USG) neck. MATERIALS AND METHODS: A total of 50 patients enrolled in this prospective study from January to December 2022. Demographic profile and clinical history were noted. Fine-needle aspirate samples were sent for TrueNAT assay, cytological examination, and ZN staining. USG neck was done for necrotic findings in the cervical lymph nodes. RESULTS: The TrueNAT positivity rate was 70%. TrueNAT sensitivity and specificity were assessed according to the cytology report, acid-fast bacilli (AFB) positivity on ZN stain, and the finding of necrosis in the cervical lymph node on the USG neck. The sensitivity and specificity of the TrueNAT assay were 80.49 and 77.78%, respectively, in accordance with necrosis on FNA cytology; 17.14 and 93.33%, respectively, in accordance with AFB positivity on ZN stain; and 74.29 and 33.33%, respectively, in accordance with lymph node necrosis on USG neck. CONCLUSION: The TrueNAT assay should be used as an adjunctive test in addition to the conventional cytological examination of the FNA sample of lymph nodes for the rapid diagnosis of tuberculosis. It also detects rifampicin resistance simultaneously.

Ultrasound-Guided Fine Needle Biopsy of Human Axillary Lymph Nodes to Assess B Cell Responses to Vaccination.

Ultrasound-guided fine needle biopsy, also known as fine needle aspiration, of human axillary lymph nodes is a safe and effective procedure to assess the immune response within the lymph nodes following vaccination. Once acquired, lymph node cells can be characterized via flow cytometric immunophenotyping and/or single-cell RNA sequencing for gene expression and T and B cell receptors. Analysis of the immune cells from the lymph nodes enables the investigation of T and B cells that may interact at this site. These interactions may lead to germinal center formation and expansion, critical for the generation of effective immunity to vaccination. Directly studying the dynamic processes and interaction of the key cells has been challenging in humans due to the anatomically protected location of these cells. Here, we describe the methods involved in ultrasound-guided fine needle biopsy of human axillary lymph nodes in response to vaccination and subsequent analyses of the B cell populations.

Process improvement in thyroid fine needle aspiration: Standardizing number of smears for enhanced adequacy and diagnosis.

Fine-needle aspiration (FNA) is a safe, cost-effective diagnostic procedure used in the evaluation of thyroid nodules. The number of thyroid FNAs has dramatically increased over the past few years. In the absence of standardized procedures regarding the number of needle passes needed for diagnosis and the lack of clarity on the use of conventional smears (CS) versus liquid-based preparations (LBP), the demand of thyroid FNAs has led to increased workload on cytology laboratories, which can negatively affect patient safety. We implemented a standardized two needle passes for CS and collection of all needle rinses and additional pass material in CytoRich Red for ThinPrep LBP and compared the non-diagnostic and diagnostic rates before and after this intervention. There were 290 pre-intervention cases and 348 post-intervention cases; of which, there were 17 (5.9%) non-diagnostic cases of the pre-intervention group and 27 (7.8) non-diagnostic cases of the post-intervention group. There was no statistically significant difference in non-diagnostic and diagnostic rates before and after the change (p = 0.347 by two-tailed Z test).

Ultrasound-Enhanced Fine-Needle Biopsy Improves Yield in Human Epithelial and Lymphoid Tissue.

OBJECTIVE: Needle biopsy is a common technique used to obtain cell and tissue samples for diagnostics. Currently, two biopsy methods are widely used: (i) fine-needle aspiration biopsy (FNAB) and (ii) core needle biopsy (CNB). However, these methods have limitations. Recently, we developed ultrasound-enhanced fine-needle aspiration biopsy (USeFNAB), which employs a needle that flexurally oscillates at an ultrasonic frequency of ∼32 kHz. The needle motion contributes to increased tissue collection while preserving cells and tissue constructs for pathological assessment. Previously, USeFNAB has been investigated only in ex vivo animal tissue. The present study was aimed at determining the feasibility of using USeFNAB in human epithelial and lymphoid tissue. METHODS: Needle biopsy samples were acquired using FNAB, CNB and USeFNAB on ex vivo human tonsils (N = 10). The tissue yield and quality were quantified by weight measurement and blinded pathologists' assessments. The biopsy methods were then compared. RESULTS: The results revealed sample mass increases of, on average, 2.3- and 5.4-fold with USeFNAB compared with the state-of-the-art FNAB and CNB, respectively. The quality of tissue fragments collected by USeFNAB was equivalent to that collected by the state-of-the-art methods in terms of morphology and immunohistochemical stainings made from cell blocks as judged by pathologists. CONCLUSION: Our study indicates that USeFNAB is a promising method that could improve tissue yield to ensure sufficient material for ancillary histochemical and molecular studies for diagnostic pathology, thereby potentially increasing diagnostic accuracy.

The efficacy and assessment value of the level of thyroglobulin wash-out after fine-needle aspiration cytodiagnosis in the evaluation of lymph node metastasis in papillary thyroid carcinoma.

OBJECTIVE: The purpose of this study was to evaluate the efficacy and clinical value of US, FNAC,FNA-Tg and FNAC + FNA-Tg, as well as the cutoff values of FNA-Tg to evaluate LN metastasis. METHODS: We analyzed the diagnostic value of different US signs, the efficiency of US, FNAC, FNA-Tg and FNAC + FNA-Tg among the LN- and LN + groups, and the cutoff value of FNA-Tg to evaluate LN metastasis. We punctured LNs multiple times and measured the levels of FNA-Tg. Furthermore, the LNs were marked with immunohistochemical Tg and LCA to distinguish the presence of Tg in the para-cancerous tissue of the LNs. RESULTS: The s-Tg and FNA-Tg of the LN + group were higher than those of the LN- group (P = 0.018, ≤ 0.001). The LN + group had more abnormal US signs than the LN- group. The cutoff value of FNA-Tg was 3.2 ng/mL. US had a high sensitivity (92.42), but the specificity was not satisfactory (55.1). FNA-Tg had a higher sensitivity (92.42 vs. 89.39), specificity (100 vs. 93.88), and accuracy (92.42 vs. 83.27) than FNAC. However, the sensitivity of FNAC + FNA-Tg increased further, while the specificity and accuracy decreased slightly. The presence of Tg in the normal lymphocytes adjacent to the cancer was confirmed. CONCLUSION: Ultrasonography provides a noninvasive, dynamic, multidimensional assessment of LNs. With a cutoff value of 3.2 ng/mL, FNA-Tg has higher accuracy and a lower false-negative rate than various single diagnoses. However, FNAC combined with FNA-Tg does not cause additional pain to patients and offers a higher diagnostic efficacy and clinical value.

Clinical Value of Fine Needle Aspiration Cytology and Core Needle Biopsy in Head and Neck Pathology - A Nationwide Survey in Germany.

BACKGROUND/AIM: Fine-needle aspiration cytology (FNA) and core needle biopsy (CNB) of the thyroid gland, salivary glands, and lymph nodes are considered simple and rapid methods for minimally invasive tissue collection. We performed a postal survey to analyse the diagnostic value and complication rate of FNA and CNB in Germany. PATIENTS AND METHODS: A questionnaire comprising 11 questions was sent to all 161 German ENT departments in September 2015. RESULTS: The response rate was 45%. In 33 of the 73 responding clinics neither FNA nor CNB were carried out. Of the 26 clinics that provided detailed reasons, the majority (n=18) cited a lack of expertise among the collaborating pathologists. Overall, FNA was used more often, regardless of the anatomical region investigated. The study was based on a total of 36,684 FNAs and 9,624 CNBs. The rate of estimated meaningful and correct findings was 63% (10%-90%) for FNA, and 83% (50%-100%) for CNB. In eight cases (<0.001%) a potential tumor cell spread was reported. CONCLUSION: This is the first nationwide survey in Germany to investigate the utility of FNA and CNB across different localizations in the head and neck region. This study revealed comparable results to the literature regarding the diagnostic value of FNA and CNB. Cell spreading was only observed in individual cases. The appraisal of needle biopsies in the head and neck area seems to be rather inhomogeneous in Germany.

Improved Diagnostic Accuracy of Thyroid Fine-Needle Aspiration Cytology with Artificial Intelligence Technology.

Background: Artificial intelligence (AI) is increasingly being applied in pathology and cytology, showing promising results. We collected a large dataset of whole slide images (WSIs) of thyroid fine-needle aspiration cytology (FNA), incorporating z-stacking, from institutions across the nation to develop an AI model. Methods: We conducted a multicenter retrospective diagnostic accuracy study using thyroid FNA dataset from the Open AI Dataset Project that consists of digitalized images samples collected from 3 university hospitals and 215 Korean institutions through extensive quality check during the case selection, scanning, labeling, and reviewing process. Multiple z-layer images were captured using three different scanners and image patches were extracted from WSIs and resized after focus fusion and color normalization. We pretested six AI models, determining Inception ResNet v2 as the best model using a subset of dataset, and subsequently tested the final model with total datasets. Additionally, we compared the performance of AI and cytopathologists using randomly selected 1031 image patches and reevaluated the cytopathologists' performance after reference to AI results. Results: A total of 10,332 image patches from 306 thyroid FNAs, comprising 78 malignant (papillary thyroid carcinoma) and 228 benign from 86 institutions were used for the AI training. Inception ResNet v2 achieved highest accuracy of 99.7%, 97.7%, and 94.9% for training, validation, and test dataset, respectively (sensitivity 99.9%, 99.6%, and 100% and specificity 99.6%, 96.4%, and 90.4% for training, validation, and test dataset, respectively). In the comparison between AI and human, AI model showed higher accuracy and specificity than the average expert cytopathologists beyond the two-standard deviation (accuracy 99.71% [95% confidence interval (CI), 99.38-100.00%] vs. 88.91% [95% CI, 86.99-90.83%], sensitivity 99.81% [95% CI, 99.54-100.00%] vs. 87.26% [95% CI, 85.22-89.30%], and specificity 99.61% [95% CI, 99.23-99.99%] vs. 90.58% [95% CI, 88.80-92.36%]). Moreover, after referring to the AI results, the performance of all the experts (accuracy 96%, 95%, and 96%, respectively) and the diagnostic agreement (from 0.64 to 0.84) increased. Conclusions: These results suggest that the application of AI technology to thyroid FNA cytology may improve the diagnostic accuracy as well as intra- and inter-observer variability among pathologists. Further confirmatory research is needed.

Performance of fine needle aspiration cytology and Ziehl-Neelsen staining technique in the diagnosis of tuberculosis lymphadenitis.

INTRODUCTION: Proper diagnosis of tuberculosis (TB) lymphadenitis is critical for its treatment and prevention. Fine needle aspirate cytology (FNAC) is the mainstay method for the diagnosis of TB lymphadenitis in Ethiopia; however, the performance of FNAC has not been evaluated in the Eastern Region of Ethiopia. This study aimed to evaluate the performance of FNAC and Ziehl-Neelsen (ZN) staining compared with that of GeneXpert for the diagnosis of TB lymphadenitis. METHODS: Fine needle aspiration (FNA) specimens collected from 291 patients suspected of having TB lymphadenitis were examined using FNAC, ZN, and GeneXpert to diagnose TB lymphadenitis. Gene-Xpert was considered the reference standard method for comparison. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and kappa coefficient were determined using SPSS version 25. RESULTS: The sensitivity, specificity, PPV, and NPV of ZN for diagnosing TB lymphadenitis were 73.2%, 97.4%, 96.2%, and 80.1% respectively. There was poor agreement between ZN and GeneXpert (Kappa=-0.253). The sensitivity, specificity, PPV, and NPV of FNAC were 83.3%, 94.8%, 93.5%, and 86.3% respectively. There was moderate agreement between the FNAC and GeneXpert (Kappa = 0.785). CONCLUSION: The fine needle aspiration cytology (FNAC) is a more sensitive test for the diagnosis of TB lymphadenitis than ZN. The FNAC showed a moderate agreement with the GeneXpert assay. This study recommends the FNA GeneXpert MTB/RIF test in preference to FNAC for the diagnosis of TB lymphadenitis to avoid a missed diagnosis of smear-negative TB lymphadenitis.

[Expert consensus on ultrasound guided thyroid and neck lymph node puncture (2023 edition)].

Thyroid nodule and cervical lymph node biopsy is the main clinical method for evaluating the condition and determining the follow-up treatment plan. The literature on thyroid nodule puncture predominantly focuses on thyroid fine needle puncture, and there are limited systematic articles on coarse needle aspiration for thyroid-related diseases and needle biopsy of thyroid-related cervical lymph node diseases. However, this shortage of articles does not reflect the diagnostic value of coarse needle aspiration in thyroid biopsy and cervical lymph node-related diseases. Currently, different departments of many hospitals in China are conducting or planning to perform needle biopsy of thyroid and cervical lymph node-related diseases to improve the standardization and safety of related operations. Standardization is needed for the indications, contraindications, perioperative period, postoperative complications management, puncture specimen processing, and related genetic analysis of thyroid and cervical lymph node puncture. For this purpose, Interventional Ultrasound Committee of Chinese College of Interventionalists organized a panel of domestic experts in the field of thyroid diseases to discuss and formulate a consensus. Based on the latest research progress, combined with the clinical realities in China, this Expert Consensus on Ultrasound Guided Thyroid and Neck Lymph Node Puncture (2023 edition) is released.

A Training Course for Simulating Head and Neck Ultrasound-Guided Procedures Using a Gelatin Phantom Model.

OBJECTIVES: Ultrasound (US)-guided procedures can be used in the evaluation and treatment of neck masses. However, these procedures need to be practiced before being executed on humans. The aim of this study is to evaluate the efficacy of a training program using a gelatin phantom to practice US-guided procedures. METHODS: This program included a lecture and practice with a gelatin phantom. We recruited doctors from different hospitals to practice US-guided procedures, including fine-needle aspiration (FNA), core needle biopsy (CNB), percutaneous ethanol injection (PEI), and radiofrequency ablation (RFA). We used a questionnaire with a 5-point scale to evaluate the effectiveness of practicing US-guided procedures under a gelatin phantom. RESULTS: Forty-four doctors participated, and 37 of them completed the questionnaires. After training, the mean (SD) scores of the doctors were 4.68 (0.47) for "Satisfaction with this course," 4.54 (0.61) for "Ease in practicing FNA&CNB using the phantom," 4.49 (0.61) for "Ease in practicing PEI using the phantom," 4.49 (0.65) for "Ease in practicing RFA using the phantom," and 4.57 (0.55) for "The course effectively familiarizing participants with US-guided procedures." Participants without experience in US examination had higher scores than those with previous US experience, but the difference was not statistically significant. CONCLUSION: A combination of lectures and hands-on practice of US-guided procedures using a gelatin phantom is an effective educational method for doctors interested in head and neck US. After the training program, doctors gained a better understanding of the necessary steps and skills required for these procedures. They can correctly insert the instruments into the target lesion and perform different US-guided procedures.

Overcoming Pitfalls in Breast Fine-Needle Aspiration Cytology: A Practical Review.

BACKGROUND: Fine-needle aspiration cytology (FNAC) is a cornerstone technique for the initial assessment of breast lesions, offering a rapid and minimally invasive option for cytological evaluation. While FNACs can forego the need for core needle biopsies (CNBs), variations in technique, subjective interpretation, and intrinsic limitations present diagnostic challenges. The International Academy of Cytology (IAC) established the Yokohama system and is developing the WHO Reporting System for Breast Cytopathology jointly with IARC, to standardize diagnostic criteria, aiming to enhance diagnostic precision and consistency. Due to the preference for CNBs, expertise in breast FNAC is low in the developed world. SUMMARY: This review assesses common pitfalls in breast cytopathology. These common and uncommon entities may easily lead to false-negative or false-positive diagnoses, due to morphological overlap or misleading clinical and radiological contexts. For instance, pauci-cellular lesions, such as lobular carcinomas, often lead to false-negative diagnoses, whereas complex sclerosing lesions, fibroadenomas, and papillary lesions may show concerning features, resulting in a false positive. The same is true for some benign inflammatory pathologies, such as steatonecrosis, and uncommon lesions, such as collagenous spherulosis. Ductal carcinoma in situ can lead to both false-negative and false-positive diagnoses, and high-grade lesions are impossible to tell apart from invasive carcinomas. These are discussed in detail. Procedural and preanalytical conditions, and the role of ancillary testing, are also briefly addressed. KEY MESSAGES: Breast FNAB is a powerful diagnostic technique, fast and minimally invasive. Even in contexts which lack expertise, this technique can be successfully adopted with a cautious approach and as long as pitfalls are kept in mind, benefiting patients and healthcare systems.

Differential diagnosis of thyroid nodules using heterogeneity quantification software on ultrasound images: correlation with the Bethesda system and surgical pathology.

Ultrasonography (US)-guided fine-needle aspiration cytology (FNAC) is the primary modality for evaluating thyroid nodules. However, in cases of atypia of undetermined significance (AUS) or follicular lesion of undetermined significance (FLUS), supplemental tests are necessary for a definitive diagnosis. Accordingly, we aimed to develop a non-invasive quantification software using the heterogeneity scores of thyroid nodules. This cross-sectional study retrospectively enrolled 188 patients who were categorized into four groups according to their diagnostic classification in the Bethesda system and surgical pathology [II-benign (B) (n = 24); III-B (n = 52); III-malignant (M) (n = 54); V/VI-M (n = 58)]. Heterogeneity scores were derived using an image pixel-based heterogeneity index, utilized as a coefficient of variation (CV) value, and analyzed across all US images. Differences in heterogeneity scores were compared using one-way analysis of variance with Tukey's test. Diagnostic accuracy was determined by calculating the area under the receiver operating characteristic (AUROC) curve. The results of this study indicated significant differences in mean heterogeneity scores between benign and malignant thyroid nodules, except in the comparison between III-M and V/VI-M nodules. Among malignant nodules, the Bethesda classification was not observed to be associated with mean heterogeneity scores. Moreover, there was a positive correlation between heterogeneity scores and the combined diagnostic category, which was based on the Bethesda system and surgical cytology grades (R = 0.639, p < 0.001). AUROC for heterogeneity scores showed the highest diagnostic performance (0.818; cut-off: 30.22% CV value) for differentiating the benign group (normal/II-B/III-B) from the malignant group (III-M/V&VI-M), with a diagnostic accuracy of 72.5% (161/122). Quantitative heterogeneity measurement of US images is a valuable non-invasive diagnostic tool for predicting the likelihood of malignancy in thyroid nodules, including AUS or FLUS.