Thyroid nodules are a common clinical finding with an estimated prevalence of 19% to 68% in the general population. They are primarily detected by high-resolution ultrasonography (USG) procedures that were previously Although most thyroid nodules are benign, approximately 5% to 15% of them are malignant necessitating accurate evaluation to guide appropriate management (Yoon & al. 2011) [2] The increasing use of ultrasonography has led to a rise in incidental detections of glandular nodules which poses a diagnostic challenge in distinguishing benign from malignant lesions (Park et al., 2018) [3].

Ultrasonography serves as the primary imaging modality for evaluating thyroid nodules due to its non-invasive nature, high sensitivity and real-time imaging capabilities (Chung et al., 2012) [4]. Several sonographic features including hypoechogenicity, irregular margins, microcalcifications and increased vascularity have been associated with malignancy aiding in risk stratification (Batawil & Alkordy, 2014) [8]. However, sonographic evaluation alone is often insufficient to establish a definitive diagnosis necessitating further cytological and histopathological correlation (Berker et al., 2008) [5].

Fine needle aspiration biopsy (FNAB), especially when performed under ultrasound guidance, is a widely accepted technique for cytological assessment of thyroid nodules. It has demonstrated good diagnostic accuracy with sensitivity ranging from 60% to 98% and specificity exceeding 90% when distinguishing benign and malignant nodules (Mikosch et al. 2000) [7]. The Bethesda System for Reporting Thyroid Cytopathology (TBSRTC) has standardized the interpretation of FNAB results by categorizing nodules into six diagnostic tiers each with an associated malignancy risk (Moon et al., 2015) [6]. However, FNAB results may be non-diagnostic in 90% to 20% of cases and require repeat aspiration or alternative diagnostic approaches (Chung et al, 2012) [4].

Histopathological examination stands as the most reliable method for diagnosing thyroid diseases when cytology reveals insufficient details. By evaluating thyroid nodule architectural and cellular properties it enables doctors to identify between benign adenomas and follicular neoplasms as well as different thyroid carcinoma types (Berker et al., 2008) [5]. Ultrasonographic evaluations in combination with cytological analyses alongside histopathological examinations create precise diagnoses that lead to enhanced clinical choice determination while improving patient results (Gul et al., 2009) [1].

The analysis aims to explore how thyroid nodule evaluation through ultrasonographic scanning relates to pathological and cytological data to determine operational excellence for such methods in clinical settings. The research review examines diagnostic methods used to diagnose thyroid nodules while showing both the advantages and weaknesses that affect thyroid nodule care options.

Study Design and Patient Selection

The research design featured retrospective observational evaluation which took place at a Government medical College and hospital in Sundargarh to analyze patients having thyroid nodule ultrasonographic examinations. Adult patients who were 18 years or older participated in the study when thyroid nodules were found accidentally or during standard medical examinations. The analysis excluded patients who received thyroid malignancy diagnosis ahead of time together with those who underwent thyroid surgery or who lacked satisfactory medical documentation. All participants granted their consent to participate after institutional ethics approval of the study protocol.

Ultrasonographic Evaluation

Experienced radiologists who focused on thyroid imaging utilized high-resolution ultrasonography along with linear-array transducers working between 7–12 MHz for all patient scans. The sonographic evaluation analyzed multiple distinct characteristics like nodule size and its echogenicity together with its margins and calcifications with vascularity assessment and analysis of extrathyroidal growth. The Thyroid Imaging Reporting and Data System (TI-RADS) classification system allowed healthcare providers to identify the risk level of malignancy within nodules. The radiologist paid attention to concerning sonographic findings including nodule hypoechogenicity along with spiculated or irregular margins plus microcalcifications and a taller-than-wide shape because they needed additional testing.

Fine-Needle Aspiration Biopsy (FNAB) and Cytological Analysis

An experienced cytopathologist performed FNAB under ultrasound guidance by using needles of 23 to 25 gauge. The healthcare professional acquired multiple needle samples from each nodule for sufficient testing purposes. The laboratory personnel prepared the obtained samples by placing them on glass slides followed by air-drying and staining with Giemsa and Papanicolaou staining techniques. TBSRTC serves as the guideline for cytological diagnostic groups which divide thyroid nodules into non-diagnostic, benign, atypia of undetermined significance (AUS), follicular neoplasm, suspicious for malignancy, and malignant categories. Additional FNAB procedures or surgical treatment followed non-diagnostic FNAB tests until appropriate diagnosis could be established.

Histopathological Correlation

The patients who showed indeterminate or suspicious or malignant cellular findings on cytological assessment received thyroid nodule surgical removal before receiving histopathological testing. The analysis included a review of FFPE tissue sections stained with H&E for histopathological examination. The ultimate goal of histopathological analysis involved searching for benign tissue types which included nodular hyperplasia and follicular adenomas alongside malignant pathological items like papillary carcinoma and follicular carcinoma and medullary carcinoma and anaplastic carcinoma of the thyroid. The histopathological final diagnosis was compared with ultrasonographic results and cytological findings to determine diagnostic accuracy.

Statistical Analysis

The diagnostic performance of ultrasound combined with FNAB evaluation was determined based on different measures such as sensitivity and specificity as well as positive predictive value and negative predictive value. A kappa statistic computed according to Cohen measured the alignment between results obtained by cytology and histopathology. The predictive power of diagnostic characteristics for sonographic distinction between benign and malignant nodules received analysis via a receiver operating characteristic (ROC) curve assessment. The SPSS statistical software was used for analysis and researchers set the statistical significance threshold at p < 0.05.

Patient Characteristics

The research involved 250 patients who had thyroid nodules and their mean age amounted to 45.6 ± 12.3 years. The study participants included 180 female patients who made up 72 percent of the sample while 70 male patients amounted to 28 percent for an overall female-male split of 2.6:1. Ten percent of patients undergoing thyroidectomy treatment for nodules had single lesions while 36% received multiple nodule treatment. The average nodule size was 2.8 ± 1.5 cm which spanned from 0.5 cm to 6.5 cm diameters.

Ultrasonographic Findings

Of the 250 thyroid nodules evaluated with ultrasound, 110 (44%) appeared hypoechoic and 85 (34%) showed isoechoic characteristic while 55 (22%) were classified as hyperechoic. The ultrasound examinations identified suspicious features of irregular borders and microcalcifications combined with elevated vascularity in 39.2% of tissue samples. 50 nodules measured a TI-RADS 2 score since they marked as benign (20%), while TI-RADS 3 resulted in 90 nodules (36%), creating 60 nodules with a TI-RADS 4 score (24%) and 50 nodules receiving TI-RADS 5 score (20%) indicating highly suspect malignancy.

Table 1: Ultrasonographic Characteristics of Thyroid Nodules

Cytological Findings

The study evaluated FNAB biopsy results by adopting the criteria outlined in The Bethesda System for Reporting Thyroid Cytopathology (TBSRTC). Among 250 thyroid nodule patients, medical analysis revealed 90 benign cases while the remainder consisted of 40 AUS, 35 neoplastic, 30 suspicious for malignancy and 40 malignant nodules. The group of 15 (6%) cases proved non-diagnostic which required follow-up through additional FNAB or surgical biopsy testing for proper assessment.

Table 2: Cytological Classification of Thyroid Nodules Based on Bethesda System

Histopathological Correlation

The research evaluated the histological findings in 105 patients who needed thyroidectomies because of FNAB results showing indeterminate or suspicious and malignant pathology. The study revealed 50 (47.6%) malignant cases out of 105 examined patients and 55 (52.4%) benign cases. Statistical results showed papillary thyroid carcinoma was the most frequently diagnosed malignancy among patients (76% of cases) while follicular carcinoma and medullary carcinoma and anaplastic carcinoma each accounted for 16%, 6% and 2% respectively.

Ultrasonography and FNAB were examined for their ability to predict malignancy based on the results compared to final histopathology examination. Research showed that FNAB achieved a diagnostic performance with sensitivity 88.2% and specificity 91.4%, PPV 85.4% and NPV 93.1%. Ultrasonography tests on their own showed an 82.4% success rate for identifying malignant nodules along with an 80.5% accuracy for not detecting malignant nodules.

Table 3: Comparison of FNAB and Histopathology Findings

Diagnostic Performance of Imaging and FNAB

The receiver operating characteristic (ROC) curve analysis showed that combining ultrasonographic evaluation with FNAB produced better accuracy in diagnosing malignant thyroid nodule characteristics. Research findings showed an area under the curve value of 0.83 from ultrasonography then 0.91 from FNAB tests which established FNAB as the superior diagnostic assessment method.

Graph 1: ROC Curve Comparison of Ultrasonography and FNAB in Detecting Malignant Nodules

Study results showed that hypoechoic texture along with irregular margins and microcalcifications function as main ultrasonographic signs that indicate cancer. Thyroid nodule diagnosis proved highly accurate using FNAB as the test confirmed 88.2% of malignant results and 91.4% of benign outcomes. Results from surgically removed nodules through histopathological analysis revealed malignancy in 47.6% of samples where papillary carcinoma showed highest occurrence among the cases. More precise malignancy detection occurred when FNAB was used with ultrasonographic evaluation because FNAB produced an area under the ROC curve of 0.91 while ultrasonography alone delivered 0.83. The results demonstrate the necessity for multi comprehensive thyroid nodule assessment methods to improve diagnostic outcomes because they help limit surgeries while detecting cancerous tumors efficiently.

The clinical assessment of thyroid nodules demands a simultaneous use of ultrasonography combined with fine-needle aspiration biopsy (FNAB) and histopathological examination for achieving precise diagnostic results. The research showed hypoechoic texture together with irregular margins and microcalcifications proved to be the strongest diagnostic indicators on ultrasonography for malignancy. Medical literature supports the crucial role of sonographic features for risk assessment because they provide evidence for malignancy determination. Rosario et al. (2014) [9] presented evidence showing how hypoechogenicity together with irregular borders enabled strong malignancy detection when FNAB produced consistently nondiagnostic results (Bethesda category I). This proved the importance of sonographic evaluation in diagnosis when cytology results were unsatisfactory.

The FNAB method acts as a vital preoperative diagnostic tool for thyroid nodules by showing high exactness and precision to separate benign lesions from malignant ones. The diagnostic accuracy of ultrasound-guided FNAB in our study matched figures from Izquierdo et al. (2006) [10] whose data showed FNAB obtained through ultrasound guidance provided superior results than palpation guidance. Through ultrasound guidance FNAB provides precise sampling that helps researchers obtain enough material from both small and deeply placed nodules thus reducing unsatisfactory diagnostic outcomes. The diagnostic precision of FNAB is remarkable but doctors should recognize its restrictions for cases with uncertain cytology which falls under Bethesda categories III and IV. The research from Rossi et al. (2012) [11] demonstrates that BRAF V600E mutation testing along with other molecular markers provides better prediction of malignancy when cytology remains in the ambiguous category III and IV.

The histopathological evaluation revealed thyroid cancer in 47.6% of surgically obtained nodules where papillary thyroid carcinoma represented the dominant cancer type. The results support Wharry et al. (2014) [14] who found that thyroid nodule malignancy risk is higher than expected for masses larger than 4 cm which strengthens the need for detailed evaluation despite benign cytology results. The evaluation process through FNAB revealed benign findings among a group of patients who eventually received a histopathological diagnosis of malignancy demonstrating the possible limitations of cytological assessment. The study by Kwak et al. (2010) [13] demonstrated how the sonographic follow-up approach proves beneficial for benign-calcified nodules because 3% of such nodules would eventually manifest malignant behavior. Long-term sonographic examination serves as an essential tool for detecting early signs of malignancy evolution in nodules having abnormal sonographic features according to Kim et al. (2014) [12].

Our study results show a connection between thyroid nodule assessment through cytology and pathology which demonstrates the diagnostic difficulty in thyroid nodule diagnosis. The sensitivity of FNAB depends on multiple conditions that include tissue make-up as well as practitioner experience level and specimen collection methods. Proper diagnosis becomes challenging when indeterminate cytology emerges because the chance of cancer development exists across a wide spectrum of possibilities. According to Tutuncu et al. (2014) [15] indeterminate cytology in thyroid nodule assessment revealed 15% to 40% malignancy frequencies and microcalcifications along with elevated vascularity demonstrated strong associations with cancer development. Ultrasonographic risk stratification when added to FNAB testing helps enhance the identification of malignancies in thyroid nodules which assists medical professionals to make proper surgical decisions.

Medical diagnostic accuracy of thyroid nodules requires physicians to combine multiple tests through their evaluation process. The risk stratification process of ultrasonography functions most effectively through the use of FNAB as its essential cytological test method. A definitive diagnosis depends on histopathological examination above all other methods since these tests present specific obstacles during diagnosis. Results indicate that assessment through follow-ups represents a necessary step for studying thyroid nodules exhibiting initial benign FNAB results in combination with high-risk sonographic features. Medical professionals who use molecular markers together with advanced imaging techniques will reach improved diagnostic accuracy which generates superior outcomes for thyroid nodule patients.

Ultrasonography combined with fine-needle aspiration biopsy (FNAB) and follow-up histopathological examination stands as a vital diagnostic approach for evaluating thyroid nodules which helps in accurate diagnosis and patient care. The research shows that hypoechoic tissue appearance together with irregular border shapes and calcification formations help identify malignant lesions yet fine-needle aspiration biopsy demonstrates top performance in separating benign from malignant nodules. The diagnostic limitations of FNAB mostly affect cases where the cytology results are unclear thus requiring selected cases to undergo histopathological examination. The research confirms that appropriate malignancy identification relies on examining multiple sources including imaging and cytology and molecular testing as supplemental assessments to decrease invasive procedures. Ultrasonographic surveillance should be continuous for nodules with benign cytology because it helps detect any development of malignancy. Improvements in diagnostic methods that include molecular testing might enhance thyroid nodule risk assessment and improve patient results for enhanced thyroid nodule treatment.

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