Thyroid Nodule Size Research Articles

Thyroid nodule size at ultrasound as a predictor of malignancy

Thyroid nodule size at ultrasound as a predictor of malignancy

Thyroid nodule size and the risk of malignancy

Searchable abstracts of presentations at key conferences in endocrinology ISSN 1470-3947 (print) | ISSN 1479-6848 (online)

Ultrasound-Guided Fine-Needle Aspiration of Thyroid Nodules: Relation Between Radiology Thyrads Score and Bethesda Pathology Score System

Background: Although fine-needle aspiration biopsy (FNAB) is considered the standard for preoperative evaluation of thyroid nodules, the value of this has been questioned for different thyroid nodules size. Different pathology and radiological scoring may improve the accuracy of preoperative diagnosis of thyroid nudoles. The aim of this study was to evaluate the relation between radiology Thyrads score and Bethesda pathology score system size in two group size (? 10 mm and > 10 mm) of thyroid nodule in US-FNAB. Methods: There were 183 thyroid nodules between 3 mm to 35 mm who underwent US-FNAB from January 2015 to November 2016 in Shaheed Sadoughi hospital- Yazd. They were divided in to two groups (group A, 3 - 10 mm; group B, 11- 35 mm). The patients were studied according radiology Thyrads score and Bethesda pathology score system. The relation between radiology Thyrads score and Bethesda pathology score system according groups size was analyzed by SPSS21. Results: The mean age ( standard deviation) of patients was 44.5 ( 12.8 years). Most of them were female 138 (83.6%). The frequency of final pathology diagnoses were; 35(21.2%) non diagnostic, 107 (64.8%) benign, 13 (7.9%) malignant and 10 (6.1%) suspicious. no statically significance relation between thyrads score and nodule characteristics (solid/cyst (p-value: 0.555), calcification (P value: 0.558), lymph-adenopathy (P value: 0.521), ecogenicity (P value: 0.236), margin (P value:0.149)). The spearman correlation between radiology thyroids score and Bethesda pathology score system was statistically significant. (Correlation coefficient: 0.202, P value: 0.004). Conclusions: There was a statistically significance correlation between Thyrads score and pathologic Bethesda scoring system. Decision making basis on the radiologic Thyrads score can improve the radiological diagnosis precision in nodular goiter patients.

Association between lifestyle and anthropometric parameters and thyroid nodule features.

Thyroid nodularity has been associated with obesity, but data regarding associations of body composition parameters with specific ultrasound features of thyroid nodules are lacking. The aim of the present study was to assess associations between thyroid nodule ultrasound characteristics, lifestyle, and anthropometric parameters. This was a cross-sectional study in the general apparently healthy population of Northern Greece. Thyroid ultrasound data together with medical history, demographic, and anthropometric characteristics were individually recorded. Body composition was evaluated using bioelectrical impedance. Three hundred and six subjects [215 females (70.3%), aged 20-83 years] were included. Ultrasound revealed one or more thyroid nodules in 168 subjects (54.9%). Subjects with thyroid nodules were more frequently females (p = 0.033), older (p < 0.001) and had higher fat mass (p = 0.011), total body fat percentage (p < 0.001) and waist circumference (p = 0.045) than subjects without nodules. In logistic regression analyses, age and female gender were the only independent predictors of presence of thyroid nodules, as well as specific sonographic features. Additionally, total body fat percentage was positively correlated with nodule size (rho = 0.210, p = 0.006) and was the only independent predictor of hypoechoic thyroid nodule(s) and peripheral vascularity, while lack of exercise was predictive of internal vascularity. Body fat accumulation and lack of exercise, used as surrogate markers of sedentary lifestyle, influence thyroid nodule size and could predict some ultrasonographic characteristics, like hypoechoicity and internal vascularity. Therefore, routine thyroid examination of obese patients and promotion of active lifestyle may be warranted to prevent thyroid nodule formation and possibly progression to malignancy.

Thyroid nodule sizes influence the diagnostic performance of TIRADS and ultrasound patterns of 2015 ATA guidelines: a multicenter retrospective study

To evaluate the impact of thyroid nodule sizes on the diagnostic performance of thyroid imaging reporting and data system (TIRADS) and ultrasound patterns of 2015 American Thyroid Association (ATA) guidelines. Total 734 patients with 962 thyroid nodules were recruited in this retrospective study. All nodules were divided into three groups according to the maximal diameter (d < 10 mm, d = 10–20 mm and d > 20 mm). The ultrasound images were categorized based on TIRADS and ATA ultrasound patterns, respectively. A total of 931 (96.8%) and 906 (94.2%) patterns met the criteria for TIRADS and ATA ultrasound patterns. The AUC (0.849) and sensitivity (85.3%) of TIRADS were highest in d = 10–20 mm group. However, ATA had highest AUC (0.839) and specificity (89.8%) in d > 20 mm group. ATA ultrasound patterns had higher specificity (P = 0.04), while TI-RADS had higher sensitivity (P = 0.02). In nodules d > 20 mm, the specificity of ATA patterns was higher than TIRADS (P = 0.003). Our results indicated that nodule sizes may influence the diagnostic performance of TIRADS and ATA ultrasound patterns. The ATA patterns may yield higher specificity than TIRADS, especially in nodules larger than 20 mm.

Thyroid Nodule Size at Ultrasound as a Predictor of Malignancy and Final Pathologic Size.

Thyroid-related mortality has remained constant despite the increasing incidence of thyroid carcinoma. Most thyroid nodules are benign; therefore, ultrasound and fine needle aspiration (FNA) are integral in cancer screening. We hypothesize that increased nodule size at ultrasound does not predict malignancy and correlation between nodule size at ultrasound and pathologic exam is good. Resected thyroids with preoperative ultrasounds were identified. Nodule size at ultrasound, FNA diagnosis by Bethesda category, size at pathologic examination, and final histologic diagnosis were recorded. Nodule characteristics at ultrasound and FNA diagnoses were correlated with gross characteristics and histologic diagnoses. Nodules for which correlation could not be established were excluded. Of 1003 nodules from 659 patients, 26% were malignant. Nodules <2 cm had the highest malignancy rate (∼30%). Risk was similar (∼20%) for nodules ≥2 cm. Of the 548 subject to FNA, 38% were malignant. Decreasing malignancy rates were observed with increasing size (57% for nodules <1 cm to 20% for nodules >6 cm). At ultrasound size cutoffs of 2, 3, 4, and 5 cm, smaller nodules had higher malignancy rates than larger nodules. Of the 455 not subject to FNA, 11% were malignant. Ultrasound size alone is a poor predictor of malignancy, but a relatively good predictor of final pathologic size (R2 = 0.748), with less correlation at larger sizes. In nodules subject to FNA, false negative diagnoses were highest (6-8%) in nodules 3-6 cm, mostly due to encapsulated follicular variant of papillary carcinoma. Thyroid nodule size is inversely related to malignancy risk, as larger nodules have lower malignancy rates. However, the relationship of size to malignancy varies by FNA status. All nodules (regardless of FNA status) demonstrate a risk trough at ≥2 cm. Nodules subject to FNA show step-wise decline in malignancy rates by size, demonstrating that size alone should not be considered as an independent risk factor. Size at ultrasound shows relatively good correlation with final pathologic size. False negative rates are low in this series. Lesions with the appropriate constellation of clinical and radiographic findings should undergo FNA regardless of size. Both size and FNA diagnosis should influence the clinical decision-making process.

Effects of Exogenous Insulin Therapy on Thyroid Nodule Size in Patients with Type 2 Diabetes Mellitus

Recent evidence suggests that insulin resistance and endogenous hyperinsulinaemia are related to thyroid nodule growth and development, but the effect of exogenous insulin therapy on thyroid nodules is unknown.

Increased Chromosomal and Oxidative DNA Damage in Patients with Multinodular Goiter and Their Association with Cancer.

Thyroid nodules are a common clinical problem worldwide. Although thyroid cancer accounts for a small percentage of thyroid nodules, the majority are benign. 8-Hydroxy-2′-deoxyguanosine (8-OHdG) levels are a marker of oxidative stress and play a key role in the initiation and development of a range of diseases and cancer types. This study evaluates cytokinesis-block micronucleus cytome (CBMN-cyt) assay parameters and plasma 8-OHdG levels and their association with thyroid nodule size and thyroid hormones in patients with multinodular goiter. The study included 32 patients with multinodular goiter and 18 age- and sex-matched healthy controls. CBMN-cyt assay parameters in peripheral blood lymphocytes of patients with multinodular goiter and controls were evaluated, and plasma 8-OHdG levels were measured. The micronucleus (MN) frequency (chromosomal DNA damage), apoptotic and necrotic cells (cytotoxicity), and plasma 8-OHdG levels (oxidative DNA damage) were significantly higher among patients with multinodular goiter. Our study is the first report of increased chromosomal and oxidative DNA damage in patients with multinodular goiter, which may predict an increased risk of thyroid cancer in these patients. MN frequency and plasma 8-OHdG levels may be markers of the carcinogenic potential of multinodular goiters and could be used for early detection of different cancer types, including thyroid cancer.

Risk of Malignancy in Thyroid Nodules 4 cm or Larger.

BackgroundSeveral authors have questioned the accuracy of fine-needle aspiration cytology (FNAC) in large nodules. Some surgeons recommend thyroidectomy for nodules ≥4 cm even in the setting of benign FNAC, due to increased risk of malignancy and increased false negative rates in large thyroid nodules. The goal of our study was to evaluate if thyroid nodule size is associated with risk of malignancy, and to evaluate the false negative rate of FNAC for thyroid nodules ≥4 cm in our patient population.MethodsThis is a retrospective study of 85 patients with 101 thyroid nodules, who underwent thyroidectomy for thyroid nodules measuring ≥4 cm.ResultsThe overall risk of malignancy in nodules ≥4 cm was 9.9%. Nodule size was not associated with risk of malignancy (odds ratio, 1.02) after adjusting for nodule consistency, age, and sex (P=0.6). The false negative rate for FNAC was 0%.ConclusionNodule size was not associated with risk of malignancy in nodules ≥4 cm in our patient population. FNAC had a false negative rate of 0. Patients with thyroid nodules ≥4 cm and benign cytology should not automatically undergo thyroidectomy.

Correlation between Insulin Resistance and Thyroid Nodule in Type 2 Diabetes Mellitus.

Objective The present study explored the association between insulin resistance (IR) and the clinical characteristics of thyroid nodules in patients with type 2 diabetes mellitus (T2DM). Methods All the patients were newly diagnosed with T2DM. 201 patients with thyroid nodule disease and 308 patients without the nodular thyroid disease. The participants were evaluated by relevant examination. Correlation analyses and regression analyses were performed to examine the relationships between the two groups. Results HOMA-IR values, serum FT4 (free thyroxine) levels, and age were higher in the thyroid nodule group than in the control group. The proportion of women in the thyroid nodule group is greater than the proportion of women in the control group. Logistic regression analysis showed that age, sex, FT4, and HOMA-IR were positive factors for thyroid nodule. The volume and size of the thyroid nodule were positively correlated with HOMA-IR, irrespective of gender. The thyroid nodule volume and size and the TSH (thyroid stimulating hormone) were greater in females than in males, whereas FT3 (free triiodothyronine) was lower in females. Conclusion IR might be a risk factor for thyroid nodule. Whether alleviating the IR might slow the growth, or diminish the volume and size of the thyroid nodules, is yet to be elucidated.

Level I lymph node involvement in patients with N1b papillary thyroid carcinoma: a prospective study.

Most of the studies on the incidence, pattern, and predictive factors of lymph node (LN) metastasis with papillary thyroid carcinoma (PTC) have been performed retrospectively and no common consensus has been reached regarding the predictors for the involvement of level I LNs. This study was conducted prospectively to determine the incidence and the possible predictors of level I involvement in N1b PTC patients. The study included 30 consecutive patients with N1b stage of PTC. All the patients underwent neck dissection (ND) including level I. The relation between involvement of level I LNs and various clinicopathological variables was studied. Unilateral neck dissection was performed in 24 patients and bilateral neck dissection in six patients leading to 36 NDs. Level I was excised in all patients, with five specimens (14%) positive for metastasis. Levels II, III, IV, V, VI, and VII werepositivein52.8,58.3, 58.3, 33.3, 63, and 22.2%, respectively. Level I involvement was significantly related to the number of lymph node levels affected (p=0.003) and macroscopic extranodal invasion (p=0.04). It was not related to the involvement of other individual levels, gender, age, size of the largest thyroid nodule, size of the largest LN involved, or histo-pathological variant of the tumor. This study suggests that including level I in therapeutic neck dissection for N1b PTC patients might be recommended in selected cases of multiple level involvement and macroscopic extranodal invasion requiring sacrifice of internal jugular vein, spinal accessory nerve, or sternomastoid muscle.

Experience of endoscopic thyroidectomy in a single‐centre institution

AimEndoscopic thyroidectomy has been applied to various thyroid diseases to improve the cosmetic outcome of patients. Our centre has adopted the bilateral axillo‐breast approach for certain thyroid diseases. The aim of the present study was to report our experience of endoscopic thyroidectomy in comparison with open thyroidectomy to compare outcomes, complications and feasibility.Patients and MethodsBetween January 2011 and December 2014, a total of 47 patients underwent endoscopic thyroidectomy for benign thyroid diseases. From January 2013 to December 2013, a total of 60 patients who underwent open thyroidectomy with the same criteria as endoscopic thyroidectomy patients were included as the control group. Age, sex, tumour size, operative time, length of hospital stay and postoperative complications were analysed.ResultsThere was no statistically‐significant difference in terms of age, sex or size of thyroid nodule between the two groups. The majority of surgeries in both groups were hemithyroidectomies (87.2 per cent in the endoscopic group and 81.7 per cent in the open thyroidectomy group). The mean operative time for the endoscopic group was significantly longer than that of the open thyroidectomy group (238.2 + 73.6mins vs 120.2 + 38.8 min, P &lt; 0.001). The length of hospitalization was also longer in the endoscopic group (mean: 5.1 + 1.4 days vs 3.7 + 1.6 days, P &lt; 0.001). Regarding postoperative complications, there was no statistically‐significant difference in terms of hypocalcaemia, recurrent laryngeal nerve injury, skin numbness, skin burn or seroma formation.ConclusionEndoscopic thyroidectomy is a safe operative procedure, and is a feasible alternative to open thyroidectomy for benign thyroid tumours.

The impact of Chinese guideline on the managements of patients with thyroid nodules and undergoing surgery

Objective To investigate the influence of Chinese guidelines for thyroid nodules and differentiated thyroid cancers on the diagnosis and treatment of thyroid nodule patients undergoing thyroid surgery in the PLA General Hospital. Methods A retrospective analysis was conducted on data of 2 243 thyroid nodule inpatients who were undergoing thyroid surgery and with their pathology results in 2011(before the guideline change, 1 013 patients)and in 2013(after the guideline change, 1 230 patients). The data of the changes of the baseline characteristics, diagnosis, constituent of thyroid nodule, distribution of benign thyroid nodule size were compared between 2011 and 2013. The differences of surgical managements of thyroid cancer were also studied. Results (1)A higher proportion of female patients was showed in 2013 group(75.61% vs 69.20%, P<0.01). The age of patients in 2013 group was significantly younger than that of 2011 group [(45.74±11.77 vs 47.43±11.87)years old, P<0.01]. (2)Thyroid stimulating hormone and ultrasound-guided aspiration biopsy were used more often after the guideline change(83.00% vs 65.55%, 47.95% vs 19.50% respectively, both P<0.01). And the proportion of benign nodules decreased gradually in the post-guideline period(32.20% vs 49.95%, P<0.01). The sizes of benign and malignant nodules were both showed a descending tendency [(2.487±0.861 vs 2.800±0.720)cm, (1.027±0.795 vs 1.186±0.964)cm respectively, both P<0.01]. (3)After the change of guidelines, the percentage of the options of total/near-total thyroidectomy, hemithyroidectomy with isthmusectomy, and central lymph node dissection for thyroid cancer were increased(respectively 31.29% vs 15.38%, 16.91% vs 7.69%, and 64.15% vs 50.50%, all P<0.01). Conclusion After Chinese guideline was introduced in 2012, the surgical management of thyroid nodules in our hospital had been followed more closely to the recommendations of the guidelines. (Chin J Endocrinol Metab, 2016, 32: 749-753) Key words: Thyroid nodule; Guidelines; Diagnosis; Therapy

Correlation between the size of incidental thyroid nodules detected on CT, MRI or PET-CT and subsequent ultrasound

PurposeThe aim of this study was to assess the relationship between size of thyroid nodules at computed tomography (CT), magnetic resonance imaging (MRI) or positron emission tomography CT (PET-CT), and size at ultrasound. Materials and methodsWe performed a retrospective review of thyroid ultrasound studies over a 2-year period. ResultsA total of 307 patients were included in the study. There was a statistically significant difference between the size of nodules measured on ultrasound compared with cross-sectional imaging (P < .001). American College of Radiology white paper recommendations would have decreased ultrasound referrals by 24% without any additional missed malignancies. ConclusionCross-sectional imaging underestimates the size of thyroid nodules; however, the difference is small and likely not clinically significant.

Can Elastography Predict Growth of Incidental Thyroid Nodules? A Pilot Two-Year Follow-Up Study.

The objective of this study was to examine the ultrasonography (US) and ultrasound elastography (USE) features of thyroid incidentalomas in a population exposed to iodine deficiency and to investigate whether baseline elasticity scores (ES) predicted changes in thyroid nodule US characteristics. We conducted a two-year follow-up pilot study of thyroid incidentalomas by US and USE. One sonographer performed the US and USE examination on the same apparatus at baseline and at follow-up. We evaluated 83 incidental thyroid nodules detected in a population study. The follow-up period saw no change in median thyroid nodule diameter (p = 0.18) or in the prevalence of thyroid nodule US characteristics (hypoechoic: p = 0.05; solid nodule: p = 1.00; microcalcifications: p = 0.55). Individual changes in thyroid nodule diameter (>20%) were seen in 23% (11% had decreased, and 12% had increased in diameter). Changes in ES were frequently observed; 37% changed from ES A + B to ES C + D, and 27% changed from ES C + D to ES A + B. In a multivariate logistic regression model, we found no association between baseline ES and individual changes in nodule size. In an area with mild iodine deficiency and a high prevalence of thyroid nodules, thyroid USE performed on thyroid incidentalomas did not predict individual changes in thyroid nodule size.

An Electrical Impedance Tomography System for Thyroid Gland with a Tiny Electrode Array

Electrical impedance Tomography (EIT) is a non-invasive imaging technique based on measuring of the electrical conductivity and capacitance of abnormal and normal human tissues. The present work aims to develop an EIT imaging system for imaging thyroid gland. Patients with thyroid nodules were eligible for the study. The study was conducted on two groups of participants: control group consists of 20 normal female cases and experimental consists of 20 goiter female patients. The thyroid nodule location, size, and type measured by ultrasound. Thyroid gland conductivity and permittivity were recorded using EIT. The impedance measurement is done through the applying of two probes: one probe to the neck region (scanning probe) and the rest region (reference probe) with electrolytic gel for each probe, then the system software proceeds to reconstruct the image and calculate the electrical impedance of the thyroid gland on a personal computer which acts as an output display and storage for case information. The thyroid scanning probe has 64 electrodes embedded on a small space (30 mm diameter and 50 mm height) inside of the probe. Multifrequency impedance measurements are typically made by applying an electric current to a target mass by using of the scanning probe and measuring the developed voltage. The present EIT system provides real- time visualization of the spatial distribution of the electrical properties of the thyroid tissue. Images obtained from the bioimpedance (BI) were compared to images obtained from the ultrasound imaging, results showed great similarity between the two diagnostic images. Tumor tissue has higher resistance and capacitance value than that of normal thyroid gland.

The size of thyroid nodules contributing to the diagnostic efficiency of repeat fine needle aspiration cytology

Objective To evaluate the association of the size of thyroid nodules and the diagnostic value of repeat fine needle aspiration cytology(FNAC) in diagnose of thyroid nodules. Methods One hundred and forty-three thyroid nodules in one hundred and thirty-five patients with repeat FNAC and thyroidectomy were retrospectively analyzed. The nodules were divided into three groups according to the largest diameter(L) : Group A, L 1.0 cm. Yield of FNACs were divided into six levels according to the classification criteria of the Bethesda system, and Level Ⅰ, Ⅲ, Ⅳ, Ⅴ were defined as the indefinite cytological diagnosis. Results The diagnostic rate of repeat FNAC was obviously higher in group B compared with group A and group C, with significantly statistical difference (P 0.05). The diagnostic accuracy of repeat FNAC in group B was significantly higher than that in group A(P<0.05), but not in group C (P<0.05). Conclusions The repeat FNAC has a higher efficiency in those nodules with a largest diameter between 0.5 cm and 1.0 cm, and a repeat FNAC can be suggested. Key words: Ultrasonography; Thyroid nodule; Biopsy, fine needle

A meta-analysis examining the independent association between thyroid nodule size and malignancy.

Tumor size is recognized as an important predictor of malignancy in many types of cancers. However, there is no clear line of characterization when it comes to the association between thyroid nodule size and malignancy risk prediction; and the current data remains inconsistent across different studies. The aim of our study is to examine the association between nodule size and malignancy using meta-analysis of the current literature. Data sources were gathered through systemic search of PubMed, Embase and other scientific databases for articles published between January 1, 1996 and June 1, 2013. A reference group with nodule sizes <3 cm was set as a control group. Two other nodule size categories were established and these included nodules from 3-5.9 cm and nodules ≥6 cm in size. Primary outcome was a histologically proven malignancy per nodule size category. The effect sizes of clinicopathologic parameters, which are the quantitative measures of association strength between two variables, were calculated by the means of odds ratios (OR). The effect sizes were then combined using a random-effects model. Seven studies met our inclusion criteria with 10,817 thyroid nodules evaluated. Malignancy was identified in 2,206 (20.4%) nodules. After adjusting for patient age and gender, nodules that measured 3-5.9 cm had a 26% greater malignancy risk compared to those measuring <3 cm [OR, 1.26; 95% confidence interval (CI): 1.13-1.39]. However, nodules 6 cm or larger had a 16% lower risk of malignancy compared to those measuring <3 cm (OR, 0.84; 95% CI: 0.73-0.98). Thyroid nodule size predicts cancer risk. However, a threshold effect of thyroid nodule size 6 cm or greater is significantly associated with a more benign disease.

A retrospective analysis of the relationship between obesity and thyroid nodule size

Searchable abstracts of presentations at key conferences in endocrinology ISSN 1470-3947 (print) | ISSN 1479-6848 (online)

Evaluation the Relationship Between Thyroid Nodule Size with Malignancy and Accuracy of Fine Needle Aspiration Biopsy (FNAB).

Introduction:Some studies have shown largest thyroid nodule size, especially ≥4cm that can predict malignancy and reduce fine needle aspiration biopsy (FNAB) accuracy. Therefore, this study is designed to evaluate relationship between thyroid nodule sizes with malignancy and its effect on FNBA accuracy.Materials and Methods:a retrospective analytical study design aims to investigate all patients with thyroid nodules who referred to surgery department of Imam-Khomeini Hospital of Mazandaran University of Medical Sciences in Sari from 20 March 2008 to 22 March 2014. We collected patient’s demographic data, nodules size, FNAB reports and final pathology (after surgery) reports from their medical records. All data were analyses performed by SPSS18.Results:167 patients (153 women) with mean age of 41.56±13.24 years old were enrolled for this study. In final pathology; 38 patients (22.8%) had malignant nodules. The mean age of patients with or without malignant nodules were 34.93±11.86 and 42.37±12.26 years old, respectively (P=0.002). The mean size of benign and malignant nodules were 2.91±1.29 cm and 3.38±1.86 cm, respectively (P=0.15). 25.2% of <4 cm nodules and 17.9% of ≥4 cm nodules were diagnosed as a malignant (P=0.29). FNAB was done on 95 patients that reported benign in 60 patients (63.2%), malignant in 18 patients (18.9%) and suspicious in 17 patients (17.9%). Positive and negative results of FNAB in all nodules were 3.5% and 6.3%, in <4cm nodules were 5.8% and 6.2% and in ≥4cm nodules were zero and 6.7%, respectively. The sensitivity, specificity, Positive predict value (PPV), negative predict value (NPV) and overall accuracy (OA) of FNAB in all nodules were 76.19%, 96.49%, 88.88%, 91.66% and 91.02%, and in <4cm nodules were 78.57%, 94.11%, 84.61%, 91.42% and 89.58%, and in ≥4cm nodules were 71.4%, 100%, 100%, 92% and 93.33%, respectively.Conclusion:the results of this study revealed that the size of the thyroid nodules is not reliable at predicting malignancy and should not be applied in medical decision making. FNAB showed good specificity but the sensitivity was low in our study. In ≥4cm nodules; FNAB sensitivity was decreased and accompanied by higher false-negative results. Furthermore, FNABs with suspicious results were associated with high probability of malignancy.