The Combined Role of Ultrasound and Frozen Section in Surgical Management of Thyroid Nodules Read as Suspicious for Papillary Thyroid Carcinoma on Fine Needle Aspiration Biopsy: A Retrospective Study

Risk Factors for Malignancy in Patients with Multinodular Goiter

Introduction  The identification of thyroid cancer may be conducted through clinical detection, imaging method, and histopathological examination. Both solitary nodules and multinodular goiter are associated with malignancy. Objective  To assess the risk factors for malignancy among patients with multinodular goiter submitted to total thyroidectomy. Methods  A series of 712 consecutive patients, submitted to total thyroidectomy between 2005 and 2016 with multinodular goiter regarding clinical, ultrasound, and pathological variables, was retrospectively evaluated. Results  There were 408 cases of papillary carcinoma (57.3%), with the remaining being benign. Gender had no statistical significance ( p  = 0.169) for malignancy, unlike the Bethesda index, higher age group ( p  = 0.005), shorter clinical history time ( p  = 0.036), smaller number of nodules ( p  < 0.0001), and smaller nodule size ( p  < 0.0001), which were related to malignancy. Conclusion  The Bethesda index, older age group, shorter clinical history, smaller number of nodules, and smaller size of nodule were related to the diagnosis of papillary carcinoma.

Qualitative and Semiquantitative Elastography for the Diagnosis of Intermediate Suspicious Thyroid Nodules Based on the 2015 American Thyroid Association Guidelines

OBJECTIVES

To evaluate qualitative and semiquantitative elastography for the diagnosis of intermediate suspicious thyroid nodules based on the 2015 American Thyroid Association (ATA) guidelines.

METHODS

Through a retrospective search of our institutional database, 746 solid thyroid nodules found on grayscale ultrasonography, strain elastography, and ultrasound-guided fine-needle aspiration between June and November 2009 were collected. Among them, 80 nodules from 80 patients with an intermediate suspicion of malignancy based on the 2015 ATA guidelines that were 10 mm or larger were recruited as the final study nodules. Elastographic findings were categorized according to the criteria of Rago et al (J Clin Endocrinol Metab 2007; 92:2917-2922) and Asteria et al (Thyroid 2008; 18:523-531), and strain ratio values were calculated and recorded. The independent 2-sample t test and χ² test (or Fisher exact test) were used to evaluate differences in clinical parameters between benign and malignant thyroid nodules. All variables were compared by univariate and multivariate logistic regression analyses, and odds ratios with 95% confidence intervals were calculated.

RESULTS

Of the 80 nodules, 6 (7.5%) were malignant, and 74 (92.5%) were benign. No significant differences were observed in age, sex, nodule size, elasticity score, and strain ratio between benign and malignant nodules. No variables significantly predicted thyroid malignancy on the univariate analysis. On the multivariate logistic regression analysis, there were no independent variables associated with thyroid malignancy, including the elasticity score and strain ratio (all P > .05).

CONCLUSIONS

Elastographic analysis using the elasticity score and strain ratio has limited ability to characterize the benignity or malignancy of thyroid nodules with an intermediate suspicion of malignancy based on the 2015 ATA guidelines.

Economic Impact of Frozen Section for Thyroid Nodules with "Suspicious for Malignancy" Cytology

Objective To perform a cost analysis of the routine use of intraoperative frozen section (iFS) among patients undergoing a thyroid lobectomy with "suspicious for malignancy" (SUSP) cytology in the context of the 2015 American Thyroid Association guidelines. Study Design Case series with chart review; cost minimization analysis. Setting Academic. Subjects and Methods Records were reviewed for patients with SUSP cytology who underwent thyroid surgery between 2010 and 2015 in which iFS was utilized. The diagnostic test performance of iFS and the frequency of indicated completion/total thyroidectomies based on the 2015 guidelines were calculated. A cost minimization analysis was performed comparing lobectomy, with and without iFS, and the need for completion thyroidectomy according to costs estimated from 2014 data from Medicare, the Bureau of Labor Statistics, and the Nationwide Inpatient Sample. Results Sixty-five patients met inclusion criteria. The malignancy rate was 61.5%, 45% of which was identified intraoperatively. The specificity and positive predictive value were 100%. The negative predictive value and sensitivity were 83% and 95%, respectively. Completion/total thyroidectomy was indicated for 9% of patients; 83% of these individuals had findings on iFS that would have changed management intraoperatively. Application of the new guidelines would have resulted in a significant reduction in the frequency of conversion to a total thyroidectomy when compared with the actual management (26.1% vs 7.7%, P = .005). Performing routine iFS was the less costly scenario, resulting in a savings of $474 per case. Conclusion For patients with SUSP cytology undergoing lobectomy, routine use of iFS would result in decreased health care utilization.

Management of Childhood Thyroid Nodules: Surgical and Endocrinological Findings in a Large Group of Cases

OBJECTIVE

The management of childhood thyroid nodules is still a big challenge for clinicians. In this study, we aimed to present our surgical and endocrinological experience in more than one hundred pediatric cases.

METHODS

A retrospective analysis of patients admitted with a thyroid nodule between 2006 and 2014 was performed. Detailed ultrasonography and fine-needle aspiration biopsy (FNAB) were the cornerstones of the diagnostic approach.

RESULTS

One hundred-three children (72 female, 31 male) with a mean age of 13.1±3.6 years (3-18 years) were admitted to our center. Management strategy was surgery in 58 patients and follow-up in 45 patients. Mean nodule size was 17±12.7 mm (2-45 mm). The diagnoses were listed as benign solitary nodule (48 patients), thyroid carcinoma (26 patients), multinodular goiter (23 patients), Hashimoto thyroiditis (4 patients), and Graves' disease (2 patients). Surgical procedures were nodulectomy/lobectomy (32 patients), total thyroidectomy (TT) (13 patients), or TT+ neck dissection (13 patients). The rate of malignancy was 25% in the total group and 44% in the surgery group. The malignancy rate was higher in patients younger than 12 years compared to older children (41% vs. 17%, p=0.040). Metastasis was seen in 38% of the malignant nodules. Postoperative complications were transient hypocalcemia (8%), permanent hypocalcemia (1.7%), and unilateral vocal cord paralysis (1.7%). Recurrence or mortality was not encountered in the 5.4±1.2-year follow-up period.

CONCLUSION

Thyroid nodule in a child requires an aggressive diagnostic approach due to increased risk of malignancy and metastasis. Intraoperative frozen section examination must be done as a useful adjunct to determine the surgical strategy. Incidence of complications is small in thyroid surgery when performed by experienced surgeons.

Validation of American Thyroid Association Ultrasound Risk Assessment of Thyroid Nodules Selected for Ultrasound Fine-Needle Aspiration

OBJECTIVE

The aim of this study was to validate the American Thyroid Association (ATA) sonographic risk assessment of thyroid nodules.

METHODS

The ATA sonographic risk assessment was prospectively applied to 206 thyroid nodules selected for ultrasound-guided fine-needle aspiration (US-FNA), and analyzed with The Bethesda System for Reporting Thyroid Cytopathology (TBSRTC), as well as surgical pathology for the subset undergoing surgical excision.

RESULTS

The analysis included 206 thyroid nodules averaging 2.4 cm (range 1-7 cm; standard error of the mean 0.07). Using the ATA US pattern risk assessment, nodules were classified as high (4%), intermediate (31%), low (38%), and very low (26%) risk of malignancy. Nodule size was inversely correlated with sonographic risk assessment, as lower risk nodules were larger on average (p < 0.0001). Malignancy rates determined by cytology/surgical pathology were high 100%, intermediate 11%, low 8%, and very low 2%, which were closely aligned with ATA malignancy risk estimates (high 70-90%, intermediate 10-20%, low 5-10%, and very low 3%). ATA US pattern risk assessment also appropriately predicted the proportion of nodules classified as malignant or suspicious for malignancy through TBSRTC classification-high (77%), intermediate (6%), low (1%), and very low 0%-as well as benign TBSRTC classification-high (0%), intermediate (47%), low (61%), and very low (70%) (p < 0.0001). Malignancy rates of surgically excised, cytologically indeterminate nodules followed ATA sonographic risk stratification (high 100%, intermediate 21%, low 17%, and very low 12%; p = 0.003).

CONCLUSION

This prospective study supports the new ATA sonographic pattern risk assessment for selection of thyroid nodules for US-FNA based upon TBSRTC and surgical pathology results. In the setting of indeterminate cytopathology, nodules categorized as atypia of undetermined significance/follicular lesion of undetermined significance with ATA high-risk sonographic patterns have a high likelihood of being malignant.

Intraoperative frozen section can be reduced in thyroid nodules classified as Bethesda categories V and VI

Intraoperative frozen section (FS) can be reduced during thyroid lobectomy according to the results of fine needle aspiration (FNA). We evaluated the role of intraoperative FS in thyroid nodules with different diagnostic categories of the Bethesda System for Reporting Thyroid Cytopathology by FNA. This retrospective study included 1,235 nodules collected via thyroidectomy with both preoperative FNA and intraoperative FS at the Second Affiliated Hospital of Zhejiang University School of Medicine, from January 2011 to January 2014. FNA cytological diagnosis was classified into six categories, based on the Bethesda system. The diagnostic findings of FNA cytology and FS histology were compared with the final histological results. 189 nodules were benign. The remainder were malignant. FS diagnosis was more accurate than FNA diagnosis for nodules classified as Bethesda Categories II, III, and IV (P < 0.05). However, the accuracy of FNA diagnosis in nodules assigned Bethesda Categories V and VI was significantly higher than that of FS (P < 0.05). FS appears be beneficial for thyroid nodules classified as Bethesda categories I through IV. FS may not be necessary in nodules diagnosed as Bethesda Categories V and VI.

Utility of intraoperative frozen sections for thyroid nodules with prior fine needle aspiration cytology diagnosis

INTRODUCTION

The objective of this study was to evaluate the role of intraoperative frozen section (IFS) in determining the course of surgery in thyroid nodules with a prior fine needle aspiration (FNA) biopsy diagnosis. In addition, reliability of FNA interpretation to guide surgical management without IFS was investigated.

MATERIAL AND METHODS

This is a retrospective study of all patients who had a FNA biopsy, IFS, and final pathology performed on a thyroid nodule over a 9 month period. The extent of surgery at the time of the IFS was recorded. Subsequent change in surgical procedure following the IFS diagnosis was noted in each of the Bethesda diagnostic categories.

RESULTS

55% of the cases were deferred at IFS overall, with 68 and 86% in Bethesda III and IV categories, respectively. Overall, there was a change in management in 6% of cases.

CONCLUSIONS

Our study does not support the use of IFS for nodules with prior FNA interpretation of Bethesda II, III, IV and VI as management was not significantly changed. IFS is of value for nodules with prior FNA diagnosis of Bethesda I for interpretation of nodule, and Bethesda V for planning surgery. A confirmatory diagnosis could not be rendered at IFS for lesions with follicular architecture, which comprised most of the cases in Bethesda III and IV.

Intraoperative Frozen Section in “Suspicious for Papillary Thyroid Carcinoma” after Adoption of the Bethesda System

Objective

To evaluate the accuracy and utility of intraoperative frozen section examination (iFSE) in patients with a preoperative fine-needle aspiration (FNA) cytology of “suspicious for malignancy” (SFM)–Bethesda V, after the adoption of the Bethesda System for Reporting Thyroid Cytopathology.

Study Design

Case series with chart review.

Setting

Tertiary medical center.

Subjects and Methods

All patients with SFM–Bethesda V who underwent thyroid surgery with iFSE between 2010 and 2015 were included. In cases where the iFSE was reported to be malignant, a total thyroidectomy was performed; otherwise, thyroid lobectomy (hemithyroidectomy) was performed.

Results

The current series included 47 patients diagnosed preoperatively with FNA cytology of SFM–Bethesda V. The malignancy rate was 74.5% (35 of 47). Twenty-four patients with nonmalignant iFSE results underwent lobectomy during their initial surgery: 12 were subsequently found with benign final histology and did not undergo completion thyroidectomy; the other 12 patients had malignant results on final histology, but only 4 of them underwent completion thyroidectomy. iFSE resulted in a sensitivity and specificity of 65.7% and 100%, respectively, with a positive predictive value of 100% (23 of 23) and a negative predictive value of 50% (12 of 24). Accuracy of the iFSE methodology was 74.5% (35 of 47).

Conclusions

With no significant preoperative clinical or sonographic predictors for thyroid malignancy and given the high specificity of iFSE, our results support the use of iFSE for patients with preoperative FNA cytology of SFM–Bethesda V who are undergoing thyroid surgery, to determine the extent of required surgery.

Follow-up ultrasound may be enough for thyroid nodules from 5 mm to 1 cm in size

We investigated whether follow-up ultrasound (US) is enough for thyroid nodules 5-10 mm, and whether 3 years of interval between the initial US and next US is appropriate. This retrospective study was approved by the Institutional Review Board, and the need to obtain informed consent was waived. The study included 447 thyroid nodules 5-10 mm from 378 patients who underwent initial thyroid US, and underwent 3 years or more of follow-up US. The presence and characteristics of malignancy detected on follow-up were reviewed. Maximal diameters of each nodule at the initial and last US were measured. Univariate and multivariate analysis were used to assess association with nodule growth 3 mm or larger. Seven malignancies (1.6 %, 7 of 447) were detected on a mean 70.6 ± 20.3 months (range 36-104 months). Only one had growth 3 mm or larger, and all malignancies did not have extensive extrathyroidal extension, lateral lymph nodes, or distant metastasis. 6.0 % (27 of 447) of nodules had growth 3 mm or larger. Nodules in older patients were less likely to grow, and benign-looking nodules were more likely to grow. Longer follow-up time 6 years or more was not associated with growth, and no cancers were detected during the long follow-up time. Immediate US-FNA for thyroid nodules 5-10 mm are discouraged, unless suspicious metastatic lymph nodes are present. Also, a follow-up US 3 years after the initial US may be enough for these nodules.

The diagnostic accuracy of ultrasound-guided fine-needle aspiration biopsy for thyroid nodules three centimeters or larger in size

BACKGROUND AND PURPOSE

Whether under ultrasonography (US) guidance or not, fine-needle aspiration biopsy (FNAB) has some limitations, particularly in larger nodules. In this study, we aimed to evaluate the diagnostic value of US-guided fine-needle aspiration biopsy (US-FNAB) in thyroid nodules equal to or larger than 3 cm.

MATERIALS AND METHODS

Data of 267 patients operated for nodular goiter in the period of January 2006 and March 2012 were reviewed retrospectively. The study group (40 males, 104 females; mean age 42.3 ± 12.3, between 17 and 71) consisted of patients with nodules with a diameter of 3 cm or larger. Patients with nodules less than 3 cm in diameter were considered as the control group (27 males, 96 females; mean age 44.4 ± 11.9, between 18 and 71).

RESULTS

For nodules smaller than 3 cm, US-FNAB had an accuracy rate of 60% and a false negativity rate of 21.9%. In nodules equal to or larger than 3 cm, the accuracy rate of US-FNAB was 80%, with a false negativity rate of 6.7%. Malignancy was observed in 16% of the study group and 42.3% of the control group.

CONCLUSION

This study showed that increased nodule diameter is not associated with limitations in the diagnostic value of US-FNAB. We also found that the malignancy rate was smaller for larger nodules. This finding reflects the importance of accurate and rational diagnostic work-up and clinical management for detecting malignancy and surgical decision-making.

Current role and value of fine-needle aspiration in nodular goitre

Thyroid nodules are common and, depending on the detection technique used, can affect 50% or greater of the population. The primary diagnostic test to assess the nature of these nodules is fine-needle aspiration cytology. Most thyroid nodules are benign and often are multiple. However, the morphology of these nodules may mimic neoplasms showing features such as papillary growth, micro-follicles and even oncocytic metaplasia. Lesions with these features may be considered indeterminate for neoplasm or malignancy, and often require surgical excision to define their nature. The role of cytopathology in this area is to screen those definitely benign nodules, thus preventing surgery and reassuring both the patient and the clinician. In this review, we demonstrate many of the morphological manifestations of nodular goiter and stress the necessity of careful preparatory techniques. Although the past several years have witnessed the development of molecular testing to refine diagnostic cytology in the thyroid, it is still the role of the cytopathologist to identify those "indeterminant" nodules which should be tested. Thus, the cytopathologist contributes both an essential diagnostic and an important cost saving role which hopefully will continue in the future.

Better understanding in the differentiation of thyroid follicular adenoma, follicular carcinoma, and follicular variant of papillary carcinoma: a retrospective study

Background. To evaluate the role of ultrasonography (US), US-guided fine-needle aspiration (USFNA) and intraoperative frozen section (FS) in follicular neoplasm. Methods. US features, USFNA cytology, and FS results were compared based on the pathology results of patients with follicular adenoma (FA), follicular carcinoma (FC), and follicular variant of papillary thyroid carcinoma (FVPTC). Results. FC and FVPTC showed significantly higher rates of suspicious US features (P < 0.05) and positive findings on either US or cytology, 80.0% and 90.7%, compared to FA, 64.5% (P = 0.001). Intraoperative FS showed higher malignant rates in FVPTC and FC (81.8% and 75.0%, resp.), compared to FA (3.8%, P < 0.001). Conclusion. Suspicious US features were more significantly seen in FC and FVPTC compared to FA. Intraoperative FS is useful in the differential diagnosis of these lesions and supplements cytology results of USFNA.

Cytological results of ultrasound-guided fine-needle aspiration cytology for thyroid nodules: emphasis on correlation with sonographic findings

PURPOSE

To compare the cytological results of ultrasound-guided fine-needle aspiration (US-FNA) cytology of thyroid nodules to sonographic findings and determine whether US findings are helpful in the interpretation of cytological results.

MATERIALS AND METHODS

Among the thyroid nodules that underwent US-FNA cytology, we included the 819 nodules which had a conclusive diagnosis. Final diagnosis was based on pathology from surgery, repeated FNA cytology or follow-up of more than one year. Cytological results were divided into five groups: benign, indeterminate (follicular or Hurthle cell neoplasm), suspicious for malignancy, malignant, and inadequate. US findings were categorized as benign or suspicious. Cytological results and US categories were analyzed.

RESULTS

Final diagnosis was concluded upon in 819 nodules based on pathology (n=311), repeated FNA cytology (n=204) and follow-up (n=304), of which 634 were benign and 185 were malignant. There were 560 benign nodules, 141 malignant nodules, 49 nodules with inadequate results, 21 with indeterminate results, and 48 that were suspicious for malignancy. The positive and negative predictive values of the US categories were 59.1% and 97.0%, and those of the cytological results were 93.7% and 98.9%. The US categories were significantly correlated with final diagnosis in the benign (p=0.014) and suspicious for malignancy (p<0.001) cytological result groups, but not in the inadequate and indeterminate cytological results groups. The false positive and negative rates of cytological results were 1.9% and 3.2%.

CONCLUSION

Sonographic findings can be useful when used alongside cytological results, especially in nodules with cytological results that are benign or suspicious for malignancy.

The diagnostic accuracy of ultrasound-guided fine-needle aspiration biopsy and the sonographic differences between benign and malignant thyroid nodules 3 cm or larger

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 large thyroid nodules. Here, we evaluated the diagnostic accuracy of ultrasound-guided FNAB (US-FNAB) for thyroid nodules that were 3 cm or larger as well as the sonographic differences between benign and malignant nodules in this size group.

MATERIALS AND METHODS

There were 661 thyroid masses equal to or larger than 3 cm who underwent US-FNAB from February 2002 to December 2006 and were included in this study. The cytology and surgical pathology readings in these patients were reviewed along with the ultrasonography features, the last from the retrospective review by one radiologist. Histopathology was used to calculate accuracy parameters for the US-FNAB cytology readings. In addition, the likely diagnoses for patients with a benign cytology reading were ascertained.

RESULTS

Thyroid surgery was performed for 206 of the 661 nodules in the same number of patients (31.2%). All subjects who had inadequate, indeterminate, or suspicious for malignancy cytology readings had thyroid surgery. All of the patients who did not have thyroid surgery were considered likely to have benign disease because of their initial cytology reading and follow-up, and finally, 587 (88.8%) were benign and 74 (11.2%) were malignant. When considering malignant, suspicious for malignancy, and indeterminate cytology readings as positive and benign cytology as negative, the sensitivity was 96.7%, specificity 85.9%, positive predictive value 76.6%, negative predictive value 98.2%, and accuracy 89.4%. Ultrasonography features of malignancy were more prevalent in thyroid nodules that were malignant compared with those that were benign or considered likely to be benign (70.3% vs. 1.2%, p < 0.001), and ultrasonography features of a benign nodule were more prevalent in thyroid nodules that were benign or considered likely to be benign than those that were malignant (94.9% vs. 29.7%, p < 0.001).

CONCLUSION

In this study, US-FNAB appeared to be a relatively accurate method to evaluate thyroid nodules larger than 3 cm, with false-negative rates of about 2%. Much larger series would be required to determine its utility in this setting.

Fine-Needle Aspiration and Intraoperative Consultation in Thyroid Pathology: When and How?

Fine-needle aspiration (FNA) and frozen section evaluation are traditional components of the management of thyroid lesions. Their role and usefulness are dictated by some basic facts about thyroid pathology: ( a) nodules are very common; ( b ) they are benign in the majority of cases; and ( c) the diagnosis of malignancy is primarily based on cytologic features in the case of papillary carcinoma, and on the presence of invasion of the tumor capsule or of blood vessels in the case of follicular carcinoma. The common occurrence of benign thyroid nodules mandates a cost-effective effective method for preoperative screening. Since, as already stated, the diagnosis of papillary thyroid carcinoma (by far the most common thyroid malignancy) is based on the identification of characteristic cytologic features, FNA has easily emerged in the past 30 years as the most accurate and cost-effective tool—indeed a true cornerstone—for the preoperative management of thyroid nodules. Standardized terminology to report cytologic diagnoses is highly recommended and is being implemented worldwide. Conversely, the importance of intraoperative frozen section diagnosis has been constantly decreasing over the past years, as a direct consequence of the widespread application of FNA. It may, however, be very useful in cases that are suspicious for papillary carcinoma on FNA and in selected cases with an indeterminate cytologic diagnosis.

Inadequate cytology in thyroid nodules: should we repeat aspiration or follow-up?

BACKGROUND

To evaluate how to correctly manage thyroid nodules showing inadequate cytology after ultrasound (US)-guided fine-needle aspiration biopsy (US-FNAB).

MATERIALS AND METHODS

A total of 393 thyroid nodules with inadequate cytology in 351 patients (M:F = 40:311, mean age: 49.3 years) with surgery or follow-up US-FNAB for at least 1 year were included in this study. Among them, 293 (74.6%) were benign and 100 (25.4%) were malignant on final reference results. Clinical characteristics and US features were reviewed and compared.

RESULTS

Malignancy rates (39.5%) of nodules having suspicious US feature were significantly higher than those (10.9%) of nodules without any suspicious US feature (P < .001). Malignancy rates of solid nodules, mainly solid nodules, and mainly cystic nodules were 29.2, 16.7, and 9.5%, respectively, with significant differences (P = .016). Malignancy rates of nodules assessed as suspicious malignant to probably benign in composition are: 39.1-12.8% (P < .001) in solid nodules, 42.1-9.2% (P = .001) in mainly solid nodules, and 50.0-5.3% (P = .04) in mainly cystic nodules.

CONCLUSIONS

In nodules with inadequate cytology, follow-up US can be considered over repeat aspiration if there are no suspicious US features present, especially in mainly cystic nodules.

Role of ultrasonography in patients with cytologically follicular thyroid tumor

OBJECTIVE

The purpose of this study is to evaluate the role of ultrasonography (US) in the management of thyroid nodules when the cytology is indeterminate as follicular tumor on fine needle aspiration biopsy (FNAB).

METHODS

In 2006, 6586 patients with thyroid nodules, which were detected on US underwent FNAB in our department. Of these patients, we extracted 438 patients (6.7%) whose nodules were cytologically diagnosed as indeterminate. Of them, 227 patients were diagnosed as follicular tumor were enrolled in this study. Surgery was performed according to our criteria for surgical indication. We compared the results of clinical findings including US classification and final histopathological diagnosis.

RESULTS

One hundred thirty-seven of 227 underwent surgical treatment. Thirty-three (24%) were diagnosed as malignancy pathologically. Large nodule or high serum thyroglobulin level were not associated with an increased risk of malignancy. Ultrasonographic evaluation as malignancy was directly linked to pathological diagnosis as thyroid carcinoma (p<0.0001).

CONCLUSION

US plays a crucial role in deciding whether surgical treatment is necessary for cytologically indeterminate thyroid nodules as follicular tumor.

Use of ultrasound in the management of thyroid cancer

The use of ultrasound for thyroid cancer has evolved dramatically over the last few decades. Since the late 1960s, ultrasound has become essential in the examination of the thyroid gland with the increased availability of high-frequency linear array transducers and computer-enhanced imaging capabilities of modern day portable ultrasound equipment in a clinic- or office-based setting. As a noninvasive, rapid, and easily reproducible imaging study, ultrasound has been demonstrated to have a broadened utility beyond the simple confirmation of thyroid nodules and their sizes. Recently, office-based ultrasound has become an integral part of clinical practice, where it has demonstrated overwhelming benefits to patients being evaluated and treated for thyroid cancer. Ultrasound has become useful in the qualitative characterization of thyroid nodules based on benign or malignant features. On the basis of such classifications and the relative risk for thyroid malignancy, the need for ultrasound-guided fine-needle aspiration, preoperative and intraoperative staging, lymph node mapping, and the extent of surgery can subsequently be determined. Furthermore, ultrasound has additional value in the surveillance of patients treated for thyroid cancer.

How to approach thyroid nodules with indeterminate cytology

BACKGROUND

Ultrasound (US)-guided fine-needle aspiration biopsy (FNAB) is an accurate, reliable, and simple procedure to perform, and it is nowadays accepted as a standard diagnostic method for the differential diagnosis of thyroid nodules. However, a major limitation of US-FNAB is indeterminate cytology results at a thyroid nodule. This study investigated the clinical and US characteristics that predict malignancy, as well as the role of intraoperative frozen sections (FS) in the treatment of thyroid nodules with indeterminate cytology.

METHODS

From September 2002 to December 2007, the medical records of 181 patients (185 nodules) with indeterminate FNAB cytology results were retrospectively reviewed. Among them, 99 patients (M:F = 13:86; mean age, 43.71 years) with 99 thyroid nodules underwent subsequent surgery with pathologic confirmation. Seventy-eight patients (78.8%) underwent intraoperative FS. US findings of the surgically proven thyroid nodules were retrospectively reviewed. US features, clinical characteristics, and FS results were compared to the surgically proven pathologic results.

RESULTS

Nineteen nodules (19.2%) with indeterminate FNAB cytology were diagnosed as malignant. Lesion size varied from 4 to 70 mm (mean, 27.0 mm). Male patients (46.2%) were more significantly associated with malignancy than female patients (15.1%, P < 0.05). Microlobulated or ill-defined margins (87.5%), microcalcifications (50.0%), and taller-than-wide shape (80.0%) were US features showing correlations with malignancy (P < 0.05). Intraoperative FS significantly predicted malignancy (P < 0.05). Of the 78 cases with FS, 29 cases (37.2%) were deferred. Among the remaining 49 cases, 4 (5.1%) were malignant on FS and subsequent surgical pathology. Forty-five cases (57.7%) were diagnosed as benign on FS, but only two cases were diagnosed as malignant on surgical pathology.

CONCLUSIONS

Ultrasound is a feasible method in predicting malignancy in thyroid nodules with indeterminate FNAB cytology. Also, intraoperative FS is a supportive method with high specificity that may guide the treatment of thyroid nodule with indeterminate cytology.

Developments in the use of ultrasound for thyroid cancer

PURPOSE OF REVIEW

This article reviews the recent developments in neck ultrasound for thyroid cancer published in the last 18 months, with emphasis on the emerging role of surgeon-performed ultrasound in clinical endocrine practice.

RECENT FINDINGS

Ultrasound has evolved beyond the simple differentiation of solid and cystic thyroid nodules and their measurement. Although no single ultrasound feature has the highest accuracy in distinguishing between benign and malignant thyroid lesions, the combination of several ultrasound characteristics (e.g. hypoechogenicity, irregular borders and microcalcifications) within such thyroid nodules may have a stronger correlation for thyroid cancer. Based on these ultrasound features and risk for thyroid malignancy, the need for ultrasound-guided fine needle aspiration, preoperative staging, lymph node mapping and extent of surgery can subsequently be determined and performed. Furthermore, ultrasound has an additional value intraoperatively and in the postoperative surveillance of patients treated for thyroid cancer. Surgeon-performed ultrasound has recently become indispensible in clinical practice where endocrine surgeons have integrated this versatile imaging modality in the evaluation and treatment of patients with thyroid cancer.

SUMMARY

Ultrasound is an essential modality in the evaluation of thyroid malignancy. Surgeon-performed ultrasound has proved invaluable in the preoperative, intraoperative and postoperative setting. Future developments in ultrasound may lead to further improvement in the diagnostic accuracy of this modality.

The role of BRAFV600E mutation and ultrasonography for the surgical management of a thyroid nodule suspicious for papillary thyroid carcinoma on cytology

BACKGROUND

This study was designed to investigate the role of BRAFV600E mutation status in cytology specimens and ultrasonography (US) when planning surgery for thyroid nodules with cytologic results suspicious for papillary thyroid carcinoma (PTC).

METHODS

From July 2008 to November 2008, 91 consecutive patients with cytologic results of suspicious for PTC underwent thyroidectomy. Before surgery, all patients received US-guided fine needle aspiration biopsy (US-FNAB) solely for the purpose of BRAFV600E mutation analysis of thyroid nodules suspicious for PTC on cytology. BRAFV600E mutations were tested by direct sequencing. We investigated the role of BRAFV600E mutation and US in planning the thyroid surgery.

RESULTS

Of 91 nodules suspicious for PTC, 42 (46.2%) were positive for the BRAFV600E mutation and confirmed to be PTC by histopathology. The positive predictive values of BRAFV600E mutation was 100%. Of the 49 nodules without the BRAFV600E mutation, 42 (85.7%) proved to be PTC. Thirty-nine of 42 (92.9%) PTCs were suspicious for malignant features on US. Two of seven (28.6%) benign lesions showed probably benign features. The sensitivity, positive predictive value, and accuracy of US in thyroid nodules without BRAFV600E mutations was 92.9% (39/42), 88.6% (39/44), and 83.7% (41/49), respectively.

CONCLUSIONS

The BRAFV600E mutation is a useful molecular marker for preoperative diagnosis of PTC and an indicator for therapeutic thyroid surgery in the nodule with cytologic results suspicious for PTC. In thyroid nodules without the BRAFV600E mutation, suspicious malignant features on US may help in planning the extent of thyroid surgery.