Current guidelines for the application of radiofrequency ablation for thyroid nodules: a narrative review

Background and Objective

Thyroid nodules are frequently incidentally found on physical exam or imaging for an unrelated work-up. Although surgery remains the gold standard for treating symptomatic benign and/or malignant thyroid nodules, radiofrequency ablation (RFA) has emerged as a minimally invasive treatment option for high risk patients and those who decline surgery. The novel application of RFA to treat thyroid disease was originally described for symptomatic, benign thyroid nodules. Since then, several studies have tried to expand its indication to treat primary and recurrent well-differentiated thyroid cancer. The high success rates and the low complication profile, has allowed for quick adoption of RFA as a treatment option for well-selected patients with benign thyroid nodules and locoregional recurrent thyroid malignancy. As such, multidisciplinary guidelines and consensus statements were developed to standardize indications, techniques, outcome measures, and follow-up to ensure the best patient care. This article summarizes the current indications and recommendations to help guide clinicians on how best to effectively and safely utilize RFA to treat thyroid disease.

Methods

A PubMed/MEDLINE search between 2000-2022 using a combination of "radiofrequency ablation", "RFA", "thyroid nodule", and "guidelines" was conducted. The inclusion criteria were articles published in English which offered recommendations on RFA use for thyroid nodules.

Key Content and Findings

For symptomatic, benign thyroid nodules, RFA is effective at significantly reducing nodule volume. For large nodules, multiple RFA sessions may be needed to achieve clinically significant volume reduction. Patients undergoing RFA for autonomously functioning thyroid nodules may see symptomatic relief but success rates are variable. RFA may serve a curative or palliative role in recurrent well-differentiated thyroid cancers. There is little data describing the use of RFA for primary well-differentiated thyroid cancer >1 cm and the role of RFA for thyroid microcarcinomas remains controversial.

Conclusions

RFA is a safe minimally invasive technique and may be considered, in appropriate circumstances, a first-line treatment option for benign thyroid nodules. Practices adopting RFA will likely increase as more clinicians become familiar with this technique, highlighting the importance of developing standardized guidelines.

A Novel Risk Score to Predict Hungry Bone Syndrome After Parathyroidectomy for Renal Hyperparathyroidism

OBJECTIVE

Hungry bone syndrome (HBS) is a known complication of parathyroidectomy. Patients with renal hyperparathyroidism are particularly vulnerable to HBS because of their prolonged exposure to electrolyte abnormalities and elevated parathyroid hormone (PTH). However, in-depth characterization of predictive factors for HBS in these patients is lacking.

METHODS

A retrospective analysis was performed of patients with renal hyperparathyroidism who underwent parathyroidectomy at a single institution from 2011-2021. Patient demographics, clinical characteristics, and biochemical data were collected and analyzed. Boruta and binary logistic regression analyses were used to develop a scoring system.

RESULTS

Thirty-three patients were identified; 16 (48%) developed HBS. Patients with HBS had significantly higher preoperative levels of serum PTH (mean difference [MS] = 2167.2 pg/mL, P <.001), phosphorus (MD = 3.5 mg/dl, P <.001), and alkaline phosphatase (ALP) (MD = 344.2 U/L, P =.002) and significantly lower levels of preoperative serum calcium (MD = -0.96 mg/dL, P =.004). Stepwise regression analysis identified elevated ALP (>150 U/L) and markedly elevated PTH (>1000 pg/mL) as positive predictors of HBS. A two-point scoring system with these 2 variables had overall diagnostic accuracy of 96.8% (sensitivity 100% and specificity 94.1%) with 1 point conferring 93.8% positive predictive value and 2 points conferring 100% positive predictive value.

CONCLUSION

Preoperative serum PTH and ALP are significantly associated with HBS in patients with renal hyperparathyroidism undergoing parathyroidectomy for renal hyperparathyroidism. A scoring system with these 2 variables may be of clinical utility in predicting patients at high risk of HBS.

General Principles for the Safe Performance, Training, and Adoption of Ablation Techniques for Benign Thyroid Nodules: An American Thyroid Association Statement

Background: The primary goal of this interdisciplinary consensus statement is to provide a framework for the safe adoption and implementation of ablation technologies for benign thyroid nodules. Summary: This consensus statement is organized around three key themes: (1) safety of ablation techniques and their implementation, (2) optimal skillset criteria for proceduralists performing ablative procedures, and (3) defining expectations of success for this treatment option given its unique risks and benefits. Ablation safety considerations in pre-procedural, peri-procedural, and post-procedural settings are discussed, including clinical factors related to patient selection and counseling, anesthetic and technical considerations to optimize patient safety, peri-procedural risk mitigation strategies, post-procedural complication management, and safe follow-up practices. Prior training, knowledge, and steps that should be considered by any physician who desires to incorporate thyroid nodule ablation into their practice are defined and discussed. Examples of successful clinical practice implementation models of this emerging technology are provided. Conclusions: Thyroid ablative procedures provide valid alternative treatment strategies to conventional surgical management for a subset of patients with symptomatic benign thyroid nodules. Careful patient and nodule selection are critical to the success of these procedures as is extensive pre-procedural patient counseling. Although these emerging technologies hold great promise, they are not without risk and require the development of a unique skillset and environment for optimal, safe performance and consistent outcomes.

Repeat Fine-Needle Aspiration With Molecular Analysis in Management of Indeterminate Thyroid Nodules

OBJECTIVE

To analyze clinical outcomes in a series of indeterminate thyroid nodules (ITNs) with repeat fine-needle aspiration (FNA) biopsy and results of genomic classifier.

STUDY DESIGN

Historical chart review.

SETTING

Tertiary care center.

METHODS

We reviewed FNA samples from subjects with Bethesda III or IV diagnoses from January 2015 to December 2018 at a single institution and selected those with repeat FNA and ThyroSeq testing of the same nodule. Patient demographics, Bethesda classifications, ThyroSeq results, treatment detail, and surgical pathology, when available, were analyzed.

RESULTS

Ninety-six patients with cytologic diagnosis of ITN, repeat FNA, and ThyroSeq testing were identified. Following repeat FNA, 55 nodules (57%) remained ITN; 40 (42%) were reclassified as benign; and 1 (1%) was reclassified as suspicious for malignancy. In 31 patients with ThyroSeq analysis accompanying initial and repeat FNA, 26 (84%) had the same result on each, while 5 (16%) tested ThyroSeq positive following an initially negative result (κ = 0.24). Most nodules that were downgraded to Bethesda II on repeat FNA (37/40, 93%) were managed nonsurgically. Patients with ThyroSeq-positive results were treated with surgery more often (25/28, 89%) than patients with ThyroSeq-negative results (11/68, 16%; P < .0001). In excised nodules, the prevalence of malignancy and noninvasive follicular thyroid neoplasm with papillary-like nuclear features was 28% (n = 10) and 22% (n = 8), respectively, and all malignancies were low risk.

CONCLUSION

In this case series, repeat FNA helped patients with ITNs avoid diagnostic surgery through reclassification to benign cytology. The risk of high-risk malignancy in ThyroSeq-positive nodules with repeat indeterminate cytology was low.

Case Report: Giant Thyroid Angiolipoma-Challenging Clinical Diagnosis and Novel Genetic Alterations

BACKGROUND

A 64-year-old man presented with a 7.8 cm lipomatous thyroid mass discovered on magnetic resonance imaging.

METHODS

After two non-diagnostic fine needle aspirations (FNAs) were performed, computed tomography (CT) revealed features concerning for malignancy including central necrosis and infiltrative borders. A third FNA was still non-diagnostic. Total thyroidectomy was performed.

RESULTS

Upon pathologic examination, the final diagnosis was primary thyroid angiolipoma. The lesion contained central fat necrosis with ischemic features, attributable to the FNAs.

CONCLUSION

Ours is the third published case report of this rare entity. To date, no lipomatous thyroid tumor has undergone extensive genomic testing. Next-generation sequencing of our case revealed multiple genetic alterations, supporting the concept of angiolipomas being true neoplasms. Whereas the two previously reported cases in the literature were radiographically much smaller and appeared indolent, the large tumor in our case exhibited radiographic features concerning for liposarcoma, which belied the benign final pathologic diagnosis. Our case demonstrates that conservative surgical management (partial thyroidectomy) may be considered for lipomatous thyroid tumors, with further interventions to be determined only after final pathologic diagnosis.

The clinical significance of the American College of Radiology (ACR) Thyroid Imaging Reporting and Data System (TI-RADS) category 5 thyroid nodules: Not as risky as we think?

BACKGROUND

Although the prevalence of thyroid nodules is high, few prove to be malignant. Based on sonographic features, the American College of Radiology Thyroid Imaging Reporting and Data System categorizes malignancy risk of thyroid nodules with associated management recommendations for each category level. Malignancy rates among nodules with a highly suspicious Thyroid Imaging Reporting and Data System category 5 warrant examination in the context of additional risk stratification tools, including cytopathology and molecular testing.

METHODS

All patients who underwent fine-needle aspiration biopsy for Thyroid Imaging Reporting and Data System category 5 nodules from January 2018 to September 2021 in a large integrated academic health system were reviewed. Using the Bethesda System for Reporting Thyroid Cytopathology, categories V and VI were set as malignant. Molecular testing (ThyroSeq version 3; Rye Brook, NY) yielding ≥50% risk of malignancy was deemed positive and correlated with surgical pathology.

RESULTS

A total of 496 Thyroid Imaging Reporting and Data System category 5 nodules were identified. On fine-needle aspiration cytopathology, 61 (12.3%) were malignant. The breakdown included Bethesda System for Reporting Thyroid Cytopathology I, 15 (3%); II, 362 (73%); III, 52 (10.5%); IV, 5 (1%); V, 6 (1.3%); and VI, 55 (11.1%). Of Bethesda System for Reporting Thyroid Cytopathology III/IV nodules with molecular testing (n = 53), 24.5% yielded positive results. In total, 42 (8.5%) nodules underwent surgical resection, most of which were Bethesda System for Reporting Thyroid Cytopathology VI (n = 26, 61.9%). Of excised nodules, 33 (78.6%) nodules were malignant, 6 (14.3%) benign, and 3 (7.1%) noninvasive follicular thyroid neoplasm with papillary-like nuclear features. All Thyroid Imaging Reporting and Data System category 5 nodules with malignant cytology (Bethesda System for Reporting Thyroid Cytopathology V/VI) that underwent surgery were malignant on histopathology. On average, the total Thyroid Imaging Reporting and Data System points were higher in malignant nodules compared with benign (9.3 vs 7.3; P = .015). Moreover, benign nodules more frequently received Thyroid Imaging Reporting and Data System points when the radiologist was unable to determine composition or echogenicity (33% vs 3% among malignant nodules; P = .01).

CONCLUSION

Thyroid Imaging Reporting and Data System category 5 designation in thyroid nodules is associated with a lower risk of malignancy than previously reported. Benign and malignant nodules with Thyroid Imaging Reporting and Data System category 5 designation have discrepancies in certain Thyroid Imaging Reporting and Data System characteristics and individual points assigned, which may offer an opportunity for quality improvement and standardization measures in ultrasound reporting practices.

American Thyroid Association Guidelines and National Trends in Management of Papillary Thyroid Carcinoma

Importance

Over time, the American Thyroid Association (ATA) guidelines have increasingly promoted more limited treatments for well-differentiated thyroid cancers.

Objective

To determine whether the 2009 and 2015 ATA guidelines were associated with changes in the management of low-risk papillary thyroid carcinomas on a national scale.

Design, Setting, and Participants

This historical cohort study used the National Cancer Database. All papillary thyroid carcinomas diagnosed from 2004 to 2019 in the National Cancer Database were selected. Patients with tumors of greater than 4 cm, metastases, or clinical evidence of nodal disease were excluded. Data were analyzed from August 1, 2021, to September 1, 2022.

Main Outcomes and Measures

The primary aim was to tabulate changes in the rates of thyroid lobectomy (TL), total thyroidectomy (TT), and TT plus radioactive iodine (RAI) therapy after the 2009 and 2015 ATA guidelines. The secondary aim was to determine in which settings (eg, academic vs community) the practice patterns changed the most.

Results

A total of 194 254 patients (155 796 [80.2%] female patients; median [range] age at diagnosis, 51 [18-90] years) who underwent treatment during the study period were identified. Among patients who underwent surgery, rates of TL decreased from 15.1% to 13.7% after the 2009 guidelines but subsequently increased to 22.9% after the 2015 changes. Among patients undergoing TT, rates of adjuvant RAI decreased from 48.7% to 37.1% after 2009 and to 19.3% after the 2015 guidelines. Trends were similar for subgroups based on sex and race and ethnicity. However, academic institutions saw larger increases in TL rates (14.9% to 25.7%) than community hospitals (16.3% to 19.5%). Additionally, greater increases in TL rates were observed for tumors 1 to 2 cm (6.8% to 18.9%) and 2 to 4 cm (6.6% to 16.0%) than tumors less than 1 cm (22.8% to 29.2%).

Conclusions and Relevance

In this cohort study among patients with papillary thyroid carcinomas up to 4 cm, ATA guideline changes corresponded with increased TL and reduced adjuvant RAI. These changes were primarily seen in academic institutions, suggesting an opportunity to expand guideline-based care in the community setting.

Minimally Invasive Techniques for the Management of Thyroid Nodules

Image-guided interventional techniques have emerged as promising treatments for thyroid disease. Percutaneous ethanol ablation, radiofrequency ablation, laser ablation, high intensity focused ultrasound, and microwave ablation have shown efficacy in treating benign thyroid disease. There is increasing evidence that these techniques may effectively treat papillary thyroid microcarcinomas, recurrent and metastatic disease, follicular neoplasms, and parathyroid lesions. They are performed in an outpatient setting, well-tolerated, with negligible risk for thyroid hormone supplementation, making them a popular alternative to surgical resection. In this comprehensive review, we discuss the devices, techniques, advantages, and disadvantages of each intervention, and summarize the published outcomes.

American Association of Clinical Endocrinology Disease State Clinical Review: The Clinical Utility of Minimally Invasive Interventional Procedures in the Management of Benign and Malignant Thyroid Lesions

OBJECTIVE

The objective of this disease state clinical review is to provide clinicians with a summary of the nonsurgical, minimally invasive approaches to managing thyroid nodules/malignancy, including their indications, efficacy, side effects, and outcomes.

METHODS

A literature search was conducted using PubMed and appropriate key words. Relevant publications on minimally invasive thyroid techniques were used to create this clinical review.

RESULTS

Minimally invasive thyroid techniques are effective and safe when performed by experienced centers. To date, percutaneous ethanol injection therapy is recommended for recurrent benign thyroid cysts. Both ultrasound-guided laser and radiofrequency ablation can be safely used for symptomatic solid nodules, both toxic and nontoxic. Microwave ablation and high-intensity focused ultrasound are newer approaches that need further clinical evaluation. Despite limited data, encouraging results suggest that minimally invasive techniques can also be used in small-size primary and locally recurrent thyroid cancer.

CONCLUSION

Surgery and radioiodine treatment remain the conventional and established treatments for nodular goiters. However, the new image-guided minimally invasive approaches appear safe and effective alternatives when used appropriately and by trained professionals to treat symptomatic or enlarging thyroid masses.

Radiofrequency ablation and related ultrasound-guided ablation technologies for treatment of benign and malignant thyroid disease: An international multidisciplinary consensus statement of the American Head and Neck Society Endocrine Surgery Section with the Asia Pacific Society of Thyroid Surgery, Associazione Medici Endocrinologi, British Association of Endocrine and Thyroid Surgeons, European Thyroid Association, Italian Society of Endocrine Surgery Units, Korean Society of Thyroid Radiology, Latin American Thyroid Society, and Thyroid Nodules Therapies Association

BACKGROUND

The use of ultrasound-guided ablation procedures to treat both benign and malignant thyroid conditions is gaining increasing interest. This document has been developed as an international interdisciplinary evidence-based statement with a primary focus on radiofrequency ablation and is intended to serve as a manual for best practice application of ablation technologies.

METHODS

A comprehensive literature review was conducted to guide statement development and generation of best practice recommendations. Modified Delphi method was applied to assess whether statements met consensus among the entire author panel.

RESULTS

A review of the current state of ultrasound-guided ablation procedures for the treatment of benign and malignant thyroid conditions is presented. Eighteen best practice recommendations in topic areas of preprocedural evaluation, technique, postprocedural management, efficacy, potential complications, and implementation are provided.

CONCLUSIONS

As ultrasound-guided ablation procedures are increasingly utilized in benign and malignant thyroid disease, evidence-based and thoughtful application of best practices is warranted.

A comprehensive review of interventional ablation techniques for the management of thyroid nodules and metastatic lymph nodes

Thyroidectomy remains the gold standard treatment for benign, symptomatic, or enlarging thyroid nodules, malignant nodules, and metastatic lymph node disease. However, in the past 2 decades, image-guided interventional techniques have emerged as promising alternative treatments for these conditions. Percutaneous ethanol ablation is now an accepted first-line treatment for recurring cystic thyroid nodules. Thermal ablation techniques such as high-intensity focused ultrasound, laser ablation, radiofrequency ablation, and microwave ablation have shown efficacy in producing a nodular volume reduction of greater than 50% that is maintained for several years with resolution of local compressive symptoms. There is also increasing evidence that these techniques can effectively treat papillary thyroid microcarcinomas and recurrent metastatic lymph node disease. Because these interventional ablation techniques are performed safely in an outpatient setting, are well tolerated, and the risk for needing thyroid hormone supplementation is negligible, they are becoming a popular alternative treatment to surgical resection. In this comprehensive review, we discuss each of these percutaneous interventions: the devices and techniques, the advantages and disadvantages of each energy, and summarize the outcomes published in the literature.

Stones left unturned: Missed opportunities to diagnose primary hyperparathyroidism in patients with nephrolithiasis

BACKGROUND

Nephrolithiasis is a sequela of primary hyperparathyroidism and an indication for parathyroidectomy. The prevalence of primary hyperparathyroidism in patients with nephrolithiasis is 3% to 5%; however, recent studies suggest that many hypercalcemic patients with nephrolithiasis never undergo workup for primary hyperparathyroidism. Our goal is to evaluate primary hyperparathyroidism screening rates at a tertiary academic health institution and identify opportunities to increase referral rates in patients presenting with nephrolithiasis.

METHODS

We retrospectively reviewed 15,725 patients across an academic health system who presented with nephrolithiasis between 2012 and 2020. Calcium levels measured within 6 months of presentation were identified, and those with hypercalcemia (≥10.3 mg/dL) were reviewed if parathyroid hormone levels were measured. Patients with primary hyperparathyroidism were evaluated to see if they were referred to a specialist for treatment.

RESULTS

Of 15,725 patients presenting with nephrolithiasis, 12,420 (79%) had calcium levels measured; 630 patients (4.0%) were hypercalcemic, and 207 (33%) had parathyroid hormone levels measured. Patients were more likely to have parathyroid hormone levels sent if they were older, had higher calcium levels, or presented to an outpatient clinic (P = .028, P = .002, P < .001). We identified 89 patients (0.6%) with primary hyperparathyroidism, of which only 35 (39%) were referred for treatment.

CONCLUSION

The proportion of patients presenting with nephrolithiasis ultimately diagnosed with primary hyperparathyroidism was significantly lower than others have reported. Additionally, a substantial number of patients with nephrolithiasis did not have calcium and/or parathyroid hormone levels measured. These missed opportunities for diagnosis are critical as early definitive management of primary hyperparathyroidism can prevent recurrent nephrolithiasis and other primary hyperparathyroidism-related end organ effects.

Lymph node metastases in pediatric medullary thyroid carcinoma

BACKGROUND

Unlike medullary thyroid carcinoma in adults, the vast majority of pediatric medullary thyroid carcinoma is hereditary. Pediatric medullary thyroid carcinoma is known to have different genetic alterations driving tumorigenesis, but it is not known if pediatric medullary thyroid carcinoma has different clinicopathologic features. This study aims to identify which pediatric medullary thyroid carcinoma patients might warrant elective neck dissection.

METHODS

We selected all patients ages 0 to 19 diagnosed with clinically evident medullary thyroid carcinoma in the National Cancer Database between 2004 to 2016. Clinicopathologic factors, treatments, and outcomes were analyzed and compared between this cohort and adults (ages ≥20) with medullary thyroid carcinoma.

RESULTS

One hundred twenty-five pediatric medullary thyroid carcinoma (median age: 13) and 5,086 adult medullary thyroid carcinoma (median age: 57) patients were identified. Pediatric patients had smaller tumors (median diameter: 1.2 cm vs 2.0 cm; P < .001), lower rates of nodal metastases (n = 31, 36.9% vs 1,689, 50.4%; P = .02) but double the incidence of multifocal tumors (n = 70, 59.3%, vs 1,412, 29.9%; P < .001) compared with adults. Multifocal tumors conferred a significantly increased risk of nodal metastases in adult medullary thyroid carcinoma (64.4% vs 43.2%; P < .001) but not pediatric medullary thyroid carcinoma (37.7% vs 35.7%; P = .85). Nodal metastases were more frequent among older children (0-5 years: 0.0%, 6-12: 40.7%, 13-19: 41.7%; P = .04). However, rates of occult nodal metastases were similar between older children (6-19 years: n = 12, 21.4%) and adults (557, 25.8% P = .56).

CONCLUSION

Pediatric medullary thyroid carcinoma has lower rates of lymph node metastases compared with adults. The risk of nodal disease was low among the youngest children, but older children ages 6 to 19 were at considerable risk for occult metastases. These findings could guide clinicians in selecting pediatric patients considered for elective lymph node dissection.

Nodal disease burden and outcome of medullary thyroid carcinoma

BACKGROUND

Medullary thyroid carcinoma (MTC) is a rare malignancy with high incidence of cervical lymph node (CLN) metastasis. We investigated the impact of nodal disease burden on survival.

METHODS

We searched the National Cancer Database for MTC patients treated surgically. Impact of nodal metastasis on survival was analyzed using Cox univariable and multivariable regression.

RESULTS

We identified 2627 patients from 2004 to 2015. Positive CLNs were identified in 1433 (54.5%), and 542 (20.6%) had >10 CLN+. Overall survival was 94.5% and 89.6% at 3 and 5 years. Patients with 11 to 20 CLN+ had significantly worse survival than patients with 1 to 10 CLN+ in univariable and multivariable analyses (HR = 3.56 (2.31-5.50) vs 2.26 (1.60-3.20); P < .0001). The ratio of positive to dissected CLN was associated with overall survival.

CONCLUSIONS

Higher burden of nodal disease is associated with worse survival in MTC. The number of positive nodes could be a valuable prognosticator in addition to the current staging system.

Performance of a Genomic Sequencing Classifier for the Preoperative Diagnosis of Cytologically Indeterminate Thyroid Nodules

Importance

Use of next-generation sequencing of RNA and machine learning algorithms can classify the risk of malignancy in cytologically indeterminate thyroid nodules to limit unnecessary diagnostic surgery.

Objective

To measure the performance of a genomic sequencing classifier for cytologically indeterminate thyroid nodules.

Design, Setting, and Participants

A blinded validation study was conducted on a set of cytologically indeterminate thyroid nodules collected by fine-needle aspiration biopsy between June 2009 and December 2010 from 49 academic and community centers in the United States. All patients underwent surgery without genomic information and were assigned a histopathology diagnosis by an expert panel blinded to all genomic information. There were 210 potentially eligible thyroid biopsy samples with Bethesda III or IV indeterminate cytopathology that constituted a cohort previously used to validate the gene expression classifier. Of these, 191 samples (91.0%) had adequate residual RNA for validation of the genomic sequencing classifier. Algorithm development and independent validation occurred between August 2016 and May 2017.

Exposures

Thyroid nodule surgical histopathology diagnosis by an expert panel blinded to all genomic data.

Main Outcomes and Measures

The primary end point was measurement of genomic sequencing classifier sensitivity, specificity, and negative and positive predictive values in biopsies from Bethesda III and IV nodules. The secondary end point was measurement of classifier performance in biopsies from Bethesda II, V, and VI nodules.

Results

Of the 183 included patients, 142 (77.6%) were women, and the mean (range) age was 51.7 (22.0-85.0) years. The genomic sequencing classifier had a sensitivity of 91% (95% CI, 79-98) and a specificity of 68% (95% CI, 60-76). At 24% cancer prevalence, the negative predictive value was 96% (95% CI, 90-99) and the positive predictive value was 47% (95% CI, 36-58).

Conclusions and Relevance

The genomic sequencing classifier demonstrates high sensitivity and accuracy for identifying benign nodules. Its 36% increase in specificity compared with the gene expression classifier potentially increases the number of patients with benign nodules who can safely avoid unnecessary diagnostic surgery.

Heterogeneity in Positive Predictive Value of RAS Mutations in Cytologically Indeterminate Thyroid Nodules

BACKGROUND

RAS mutations are common in the available mutational analysis of cytologically indeterminate (Cyto-I) thyroid nodules. However, their reported positive predictive value (PPV) for cancer is widely variable. The reason for this variability is unknown, and it causes clinical management uncertainty. A systematic review was performed, evaluating the PPV for cancer in RAS mutation positive Cyto-I nodules, and variables that might affect residual heterogeneity across the different studies were considered.

METHODS

PubMed was searched through February 22, 2017, including studies that evaluated at least one type of RAS mutation in Cyto-I nodules, including any (or all) of the Bethesda III/IV/V categories or their equivalents and where the histological diagnosis was available. The PPV residual heterogeneity was investigated after accounting for Bethesda classification, blindedness of the histopathologist to the RAS mutational status, Bethesda category-specific cancer prevalence for each study, and which RAS genes and codons were tested. This was studied using five meta-regression models fit to different sets of Bethesda classification categories: Bethesda III, IV, or V (III/IV/V); Bethesda III or IV (III/IV); Bethesda III only; Bethesda IV only; and Bethesda V only.

RESULTS

Of 1831 studies, 23 were eligible for data inclusion. Wide ranges of PPV were found at 0-100%, 28-100%, and 0-100% in Bethesda III, IV, and V, respectively. Residual heterogeneity remained moderately high for PPV after accounting for the above moderators for Bethesda III/IV/V (21 studies; I² = 59.5%) and Bethesda III/IV (19 studies; I² = 66.0%), with significant Cochran's Q-test for residual heterogeneity (p < 0.001). Among individual Bethesda categories, residual heterogeneity was: Bethesda III (eight studies; I² = 89.0%), IV (12 studies; I² = 53.5%), and V (10 studies; I² = 34.4%), with significant Cochran's Q-test for Bethesda III (p < 0.001) and IV (p = 0.04).

CONCLUSION

The PPV of RAS mutations in Bethesda III and IV categories is quite heterogeneous across different studies, creating low confidence in the accuracy of a single estimate of PPV. Clinicians must appreciate this wide variability when managing a RAS-mutated Cyto-I nodule. Future studies should seek to resolve this unexplained variability.

Poorly Differentiated and Anaplastic Thyroid Cancer

BACKGROUND

Poorly differentiated thyroid carcinoma (PDTC) and anaplastic (undifferentiated) thyroid carcinoma (ATC) comprise a small subset of thyroid tumors that are associated with a poor prognosis and account for a significant portion of the morbidity and mortality related to thyroid cancer. Since management strategies vary between these two entities, it is important for clinicians to be able to differentiate PDTC from ATC.

METHODS

We reviewed the literature on PDTC and ATC and compared clinical and histopathologic features important in defining the disease process.

RESULTS

Both PDTC and ATC display aggressive behavior with increased locoregional and distant disease. In most cases, patients are older and have large, locally advanced tumors. PDTC may represent an intermediate entity in the progression of well-differentiated thyroid carcinoma to ATC. The use of surgical management may be curative or palliative and differs between PDTC and ATC. The roles of radiotherapy and chemotherapy have not been well described.

CONCLUSIONS

PDTC and ATC are rare diseases that carry a poor prognosis. Recognition of their different clinicopathologic features is important to the optimal management of these tumors.

Socio-demographic, Epidemiological and Environmental Determinants of Acute Gastroenteritis in Western India

INTRODUCTION

An outbreak of acute gastroenteritis had occurred in Rajpara village of Bhavnagar district. The objective of this study was to find out the socio-demographic, epidemiological and environmental determinants of this outbreak.

METHODS

A case-control study was conducted in Rajpara village among 238 cases of acute gastroenteritis and an equal number of controls in January 2015. Multiple logistic regression was used for identifying the variables independently predicting acute gastroenteritis.

RESULTS

Upper socio-economic status, occupation requiring travel outside village, source of drinking water from well of 'new' Rajpara village, change in taste of water, use of chlorine tablets, travel outside village in last week, another family member affected with acute gastroenteritis, using common utensil for hand washing, hand washing before eating, ate food from outside in last week, having sanitary latrine at house, waste disposal in a common dump (instead of at house), waste accumulation around house and flies inside house were significantly associated with occurrence of acute gastroenteritis. On multiple logistic regression, change in taste of water (P<0.001), waste disposal in a common dump (P=0.012), another family member been affected (P<0.001), waste accumulation around house (P<0.001), higher socio-economic status (P=0.002) and eating outside food (P=0.011) made a significant contribution to prediction.

CONCLUSIONS

Socio-demographic factors (higher socio-economic status), epidemiological correlates (change in taste of water, another family member been affected with acute gastroenteritis and eating outside food) and environmental determinants (waste disposal in a common dump and waste accumulation around house) significantly determines the occurrence of cases of acute gastroenteritis.

The management of thyroid nodules and cancer in the molecular era

The incidence of thyroid cancer is increasing worldwide. Current standards in the diagnosis and management of thyroid cancer are limited by the uncertainty of fine-needle aspiration samples that are indeterminate in nature. Molecular markers have the potential to improve the accuracy of thyroid fine-needle aspiration and to aid the physician in giving a more accurate diagnosis and prognosis. This paper summarizes the various molecular markers currently available.

American Thyroid Association Statement on Surgical Application of Molecular Profiling for Thyroid Nodules: Current Impact on Perioperative Decision Making

BACKGROUND

Recent advances in research on thyroid carcinogenesis have yielded applications of diagnostic molecular biomarkers and profiling panels in the management of thyroid nodules. The specific utility of these novel, clinically available molecular tests is becoming widely appreciated, especially in perioperative decision making by the surgeon regarding the need for surgery and the extent of initial resection.

METHODS

A task force was convened by the Surgical Affairs Committee of the American Thyroid Association and was charged with writing this article.

RESULTS/CONCLUSIONS

This review covers the clinical scenarios by cytologic category for which the thyroid surgeon may find molecular profiling results useful, particularly for cases with indeterminate fine-needle aspiration cytology. Distinct strengths of each ancillary test are highlighted to convey the current status of this evolving field, which has already demonstrated the potential to streamline decision making and reduce unnecessary surgery, with the accompanying benefits. However, the performance of any diagnostic test, that is, its positive predictive value and negative predictive value, are exquisitely influenced by the prevalence of cancer in that cytologic category, which is known to vary widely at different medical centers. Thus, it is crucial for the clinician to know the prevalence of malignancy within each indeterminate cytologic category, at one's own institution. Without this information, the performance of the diagnostic tests discussed below may vary substantially.

Thyroid cancers detected by imaging are not necessarily small or early stage

BACKGROUND

The incidence of well-differentiated thyroid cancer (WDTC) in the United States is increasing rapidly. Much of this increase is due to the detection by imaging of small, nonpalpable tumors. The incidence of advanced WDTC is also increasing, suggesting a true increase in the incidence of WDTC. This study was performed to determine how WDTCs of all sizes and stages are initially detected.

METHODS

A retrospective chart review of 519 patients who underwent surgery for WDTC from January 1, 2007, through August 31, 2010, was performed. A total of 473 patients suitable for inclusion in this study were divided into three groups based upon the method by which the tumor was initially detected: tumors detected by an imaging study (184 patients-39%), those detected because a mass was felt in the neck (218 patients-46%), and those detected incidentally on pathological study of the surgical specimen (71 patients-15%). Method of detection was correlated with age and sex of the patient, and size, stage, and nodal status of the tumor.

RESULTS

Patients in the Palpation group were more likely to be female (79% vs. 67% vs. 74%), younger (46 vs. 51 vs. 52), and to have larger tumors than those in the Imaging or Incidental groups. In the Imaging group, the tumor was detected on thyroid sonogram in 98 (53%), computed tomography in 38 (21%), magnetic resonance imaging in 19 (10%), carotid duplex scan in 14 (8%), and positron-emission tomography or other imaging studies in 15 (8%). Thirty-three percent of tumors <1 cm, 51% 1-2 cm, 29% 2-4 cm, and 38% >4 cm were first detected on an imaging study. Forty-seven percent of Stage III and IV cancers in patients aged ≥45 years and 39% of patients with positive central nodes were in the Imaging group.

CONCLUSION

This study demonstrates that while most tumors discovered by imaging were small and early stage, almost half of advanced (Stage III and IV) WDTCs were initially discovered by imaging studies. These findings are consistent with the hypothesis that the frequent use of imaging studies may explain not only the increasing incidence of early WDTC, but more advanced thyroid cancers as well.

Clinical and therapeutic implications of Sprouty2 feedback dysregulation in BRAF V600E-mutation-positive papillary thyroid cancer

BACKGROUND

The BRAF V600E (BRAF+) mutation activates the mitogen-activated protein kinase (MAPK/ERK) pathway and may confer an aggressive phenotype in papillary thyroid cancer (PTC). Clinically, the behavior of BRAF+ PTC, however, varies from an indolent to an aggressive course. SPRY2 is a negative feedback regulator of the MAPK/ERK pathway. We hypothesize that the level of SPRY2 expression contributes to MAPK/ERK pathway output and accounts for BRAF+ and clinical heterogeneity.

METHODS

A tissue microarray with BRAF-positive PTCs (BRAF+ PTCs) was constructed and analyzed for SPRY2 expression and MAPK/ERK output. Data were studied in the context of clinicopathologic factors to develop a risk stratification system predictive of tumor biology. SPRY2 function was studied by silencing SPRY2 in BRAF+ PTC cells. These cells were treated with MAPK/ERK pathway inhibitors and assessed for growth effects.

RESULTS

BRAF+ PTCs with an intact MAPK/ERK feedback pathway do not exhibit lymph node metastases. BRAF+ PTCs with dysregulated feedback pathways have nodal metastasis. When SPRY2 is silenced, the BRAF+ PTC cells are significantly more sensitive to MAPK/ERK inhibition.

CONCLUSION

PTC behavior likely is dependent on both the driver of the MAPK/ERK pathway and its regulatory feedback. When the feedback pathway is intact, the tumor phenotype seems to be less aggressive. This observation has direct and important clinical implications and may alter our treatment strategies.

Clinical utility of immunohistochemistry for the detection of the BRAF v600e mutation in papillary thyroid carcinoma

BACKGROUND

BRAF V600E mutation is the most common genetic alteration in papillary thyroid cancer (PTC). We used a mutation-specific antibody for immunohistochemical (IHC) detection of the BRAF V600E mutation and correlated expression with clinicopathologic features. The study was designed to validate the accuracy and determine the clinical importance of IHC detection of the BRAF V600E mutation in PTC.

METHODS

Direct sequencing and IHC for BRAF V600E mutation was performed in 37 consecutive patients with PTCs. IHC was scored on an intensity proportion scale. IHC positive tumors were stratified into intensity categories. The categories were assessed for clinicopathologic variables, including age, extrathyroidal extension, lymphovascular invasion, and lymph node metastases.

RESULTS

A total of 25 PTCs were BRAF V600E-positive and 12 were BRAF mutation-negative on IHC. The BRAF V600E mutation-specific antibody had a sensitivity of 89% and specificity of 100% for detecting the mutation. Tumors with high-intensity staining were more likely to have extrathyroidal extension.

CONCLUSION

IHC is an accurate method for the detection of the BRAF V600E mutation in PTC, and its ability to quantify the mutation expression may serve as a better predictor of tumor behavior than molecular sequencing. It provides a potentially rapid, easily applicable, and economic alternative to current techniques.

Comparative efficacy of two standard methods for determination of iron and zinc in fruits, pulses and cereals

Micronutrients are essential elements needed in small amounts for adequate human nutrition and include the elements iron and zinc. Both of these minerals are essential to human well-being and an adequate supply of iron and zinc help to prevent iron deficiency anaemia and zinc deficiency, two prevalent health concerns of the developing world. The levels of zinc and, iron were measured in the Banana, Papaya, Rice, Finger millet, Soybean and Urdbean. Standard Atomic absorption spectroscopy (AAS) method was also applied to all the samples for zinc and iron analysis and compared with inductively coupled plasma mass spectroscopy (ICP-MS). It was observed that there was no matrix interference affecting the determination of both elements interested in all the samples analyzed. Average concentration relative standard deviation and standard deviation were used for the statistical evaluation of the results for both elements. Correlation coefficient was used as statistical model to compare both the techniques.

Genetic mutations, molecular markers and future directions in research

Recent molecular studies have described a number of abnormalities associated with the pathogenesis of thyroid carcinoma. These distinct molecular events are often associated with specific stages of tumor development and may serve as prognostic factors and therapeutic targets. A better understanding of the mechanisms involved in thyroid cancer pathogenesis, will hopefully help translate these discoveries to improved patient care.

Follicular variant of papillary thyroid cancer: encapsulated, nonencapsulated, and diffuse: distinct biologic and clinical entities

OBJECTIVE

To examine genotypic and clinical differences between encapsulated, nonencapsulated, and diffuse follicular variant of papillary thyroid carcinoma (EFVPTC, NFVPTC, and diffuse FVPTC, respectively), to characterize the entities and identify predictors of their behavior.

DESIGN

Retrospective medical chart review and molecular analysis.

SETTING

Referral center of a university hospital.

PATIENTS

The pathologic characteristics of 484 consecutive patients with differentiated thyroid cancer who underwent surgery by the 3 members of the New York University Endocrine Surgery Associates from January 1, 2007, to August 1, 2010, were reviewed. Forty-five patients with FVPTC and in whom at least 1 central compartment lymph node was removed were included.

MAIN OUTCOME MEASURES

Patients with FVPTC were compared in terms of age, sex, tumor size, encapsulation, extrathyroid extension, vascular invasion, central nodal metastases, and the presence or absence of mutations in BRAF, H-RAS 12/13, K-RAS 12/13, N-RAS 12/13, H-RAS 61, K-RAS 61, N-RAS 61, and RET/PTC1.

RESULTS

No patient with EFVPTC had central lymph node metastasis, and in this group, 1 patient (4.5%) had a BRAF V600E mutation and 2 patients (9%) had RAS mutations. Of the patients with NFVPTC, none had central lymph node metastasis (P > .99) and 2 (11%) had a BRAF V600E mutation (P = .59). Of the patients with diffuse FVPTC, all had central lymph node metastasis (P < .001), and 2 (50%) had a BRAF V600E mutation (P = .06).

CONCLUSIONS

FVPTC consists of several distinct subtypes. Diffuse FVPTC seems to present and behave in a more aggressive fashion. It has a higher rate of central nodal metastasis and BRAF V600E mutation in comparison with EFVPTC and NFVPTC. Both EFVPTC and NFVPTC behave in a similar fashion. The diffuse infiltrative pattern and not just presence or absence of encapsulation seems to determine the tumor phenotype. Understanding the different subtypes of FVPTC will help guide appropriate treatment strategies.

Late solitary metastasis of renal cell carcinoma to the submandibular gland

Metastatic renal cell carcinoma to the head and neck is rare. Most reported cases of metastases to the head and neck involve the thyroid and parotid glands. Metastasis to other salivary glands is exceedingly rare. This report describes a case of a solitary metastasis of renal cell carcinoma to the submandibular gland 9 years after nephrectomy. To the authors' knowledge, this is the first case successfully diagnosed preoperatively using a combination of fine-needle aspiration and clinical history. The patient subsequently underwent a submandibular gland resection with preservation of the facial nerve branches. For the 3 years since resection of the submandibular gland, the patient has been free of disease.

Impact of the 2009 American Thyroid Association guidelines on the choice of operation for well-differentiated thyroid microcarcinomas

BACKGROUND

The 2009 ATA Guidelines state "lobectomy alone may be sufficient treatment for small (< 1 cm), low risk, unifocal, intrathyroidal papillary carcinomas in the absence of . . . nodal metastases." We determined how often these criteria are satisfied, and whether tumor size alone can dictate operative management.

METHODS

Medical records of 346 patients with well-differentiated thyroid cancer (WDTC) who underwent thyroidectomy from January 1, 2007 to November 10, 2009, were reviewed. There were 130 patients with tumors ≤ 1 cm and negative lateral nodes. Pathology reports were reviewed to identify adverse features including multifocality, extrathyroidal extension, vascular invasion, and central node metastases.

RESULTS

Eighty-four percent underwent total thyroidectomy and 16% central node dissection. All but 2 patients had papillary cancer. Sixty-one percent with cancers 6-10 mm (group 1) had adverse pathologic features compared with 32% with cancers < 6 mm (group 2). Multifocality was most common: 55% in group 1 versus 32% in group 2 (P = .004). Positive central nodes were identified in 23% of group 1 versus 4% of group 2 (P = .004). Of patients in group 1, 88% had positive or suspicious fine-needle aspiration biopsy (FNAB) preoperatively.

CONCLUSION

We recommend that total thyroidectomy be considered as the initial operation for thyroid tumors 6-10 mm in size in which the preoperative FNAB is diagnostic or suspicious for WDTC.

Squamous cell carcinoma related oncogene/DCUN1D1 is highly conserved and activated by amplification in squamous cell carcinomas

Chromosomal amplification at 3q is common to multiple human cancers, but has a specific predilection for squamous cell carcinomas (SCC) of mucosal origin. We identified and characterized a novel oncogene, SCC-related oncogene (SCCRO), which is amplified along the 3q26.3 region in human SCC. Amplification and overexpression of SCCRO in these tumors correlate with poor clinical outcome. The importance of SCCRO amplification in malignant transformation is established by the apoptotic response to short hairpin RNA against SCCRO, exclusively in cancer cell lines carrying SCCRO amplification. The oncogenic potential of SCCRO is underscored by its ability to transform fibroblasts (NIH-3T3 cells) in vitro and in vivo. We show that SCCRO regulates Gli1--a key regulator of the hedgehog (HH) pathway. Collectively, these data suggest that SCCRO is a novel component of the HH signaling pathway involved in the malignant transformation of squamous cell lineage.

Tall cell variant of papillary thyroid carcinoma without extrathyroid extension: biologic behavior and clinical implications

BACKGROUND

The tall cell variant (TCV) is a histologic subtype of papillary thyroid carcinoma (PTC) that is more aggressive than "classical" PTC. Most authors believe that TCV's worse prognosis is related to older age at presentation, larger tumor size, and high frequency of extrathyroid tumor extension (ETE). To assess the biologic and clinical behavior of TCV without ETE, we performed a detailed comparative clinicopathologic analysis of classical PTC and TCV without ETE.

METHODS

TCV was defined as a PTC harboring >50% tall cells, while classical PTC was restricted to those tumors containing >1% papillae and <30% tall cells. Microscopic analysis and chart review identified 62 cases of TCV and 83 classical PTC without ETE. These patients were analyzed for various pathologic, imaging, and clinical parameters including outcome.

RESULTS

There was no statistical difference between TCV and classical PTC in relation to age, gender, tumor size, risk stratification, type of therapy, and length of follow-up. TCV displayed more invasion of the tumor capsule and more often infiltrated into the thyroid capsule (p = 0.047 and 0.0004, respectively). Among patients with microscopically assessable regional lymph node (LN), 33 of 49 (67.3%) patients with TCV had LN metastasis at presentation, while only 24 of 60 (40%) classical PTC had positive nodes (p = 0.004). In multivariate analysis, histologic subtype (TCV vs. classical PTC) was the only independent factor associated with LN metastases (p = 0.007). In patients with adequate follow-up, 4 of 62 (6.5%) classical PTC and 7 of the 47 (14.9%) TCV had thyroid cancer recurrence (p = 0.202). TCV recurred at a distant site (3 of 47, 6.4%) while none of the 62 classical PTC developed distant metastases (p = 0.077).

CONCLUSION

TCV without ETE is biologically a more aggressive tumor than classical PTC without ETE independent of age, gender, and tumor size.