Frequency of High-Risk Characteristics Requiring Total Thyroidectomy for 1-4 cm Well-Differentiated Thyroid Cancer

BACKGROUND

The extent of thyroidectomy for low-risk well-differentiated thyroid cancer (WDTC) remains controversial. Historically, total thyroidectomy (TT) has been recommended for WDTC ≥1 cm in size. However, recent National Comprehensive Cancer Network and American Thyroid Association guidelines recognize unilateral thyroid lobectomy as a viable alternative for 1-4 cm cancers due to their otherwise favorable prognosis, with TT remaining the preferred option for tumors with unfavorable pathological characteristics. This study sought to determine how often a completion TT would be recommended based on these guidelines if lobectomy was initially performed in patients with 1-4 cm WDTC without preoperatively known risk factors.

METHODS

Patients who underwent thyroidectomy for 1-4 cm WDTC (January 2000 to January 2010) were retrospectively reviewed. Patients with preoperatively known high-risk characteristics, including gross extrathyroidal extension (ETE) on preoperative imaging, clinically apparent lymph node metastases, distant metastases, history of radiation, and positive family history, were excluded. The pathology specimens from the cancer-containing lobe were evaluated for features that would lead to a recommendation for TT based on current guidelines, including aggressive histology, vascular invasion, microscopic ETE, positive margins, and any positive lymph nodes within the specimen.

RESULTS

Of 1000 consecutive patients operated for WDTC, 287 would have been eligible for lobectomy as the initial operation. The mean age in this cohort was 45 years, and 80% were women. Aggressive tall-cell variant histology was found in one patient (0.5%), angio-invasion in 34 (12%), ETE in 48 (17%), positive margins in 51 (18%), and positive lymph nodes in 49 (18%) patients. Completion TT would have been recommended in 122/287 (43%) patients. Even in those with 1-2 cm cancers, completion TT would have been recommended in 52/143 (36%) patients.

CONCLUSIONS

Nearly half of the patients with 1-4 cm WDTC who are eligible for lobectomy under current guidelines would require completion TT based on pathological characteristics of the initial lobe. Surgeons, endocrinologists, and patients need to balance the relative benefits, risks, and costs of initial TT versus the possible need for reoperative completion TT.

The underestimated risk of cancer in patients with multinodular goiters after a benign fine needle aspiration

IMPORTANCE

Ultrasound-guided fine needle aspiration (FNA) is an excellent tool for evaluating patients with solitary thyroid nodules, with a false-negative malignancy rate of <3%. The utility of FNA in patients with a cervical multinodular goiter (MNG) is unknown, because biopsy and surveillance of thyroids with numerous nodules may be impractical.

OBJECTIVE

To evaluate the incidence and risk factors for unsuspected thyroid cancer on final pathology in patients with a non-functional, cervical MNG who had a benign preoperative FNA and underwent thyroidectomy.

DESIGN, SETTING AND PARTICIPANTS

Retrospective review of patients with non-functional, cervical MNG at a high-volume tertiary referral center between 2005 and 2012.

MAIN OUTCOME MEASURE(S)

Incidence of thyroid cancer on surgical pathology.

RESULTS

Of the 134 patients included in the study, 31 (23.1%) were found to have thyroid cancer on final pathology. Twenty-one (15.7%) patients had a microscopic papillary cancer (<1 cm) and 10 (7.5%) patients had other forms of thyroid cancer [five follicular, four papillary (>1 cm), and one patient with a papillary and follicular cancer]. On univariate analysis, male gender had a near-significant association with non-micropapillary thyroid cancer (p = 0.06). On multivariate analysis, male gender (OR = 10.2, 95% CI 1.35-76.8) and FNA cytology not reviewed at our institution (OR = 6.0, 95% CI 1.2-30) were independently associated with non-micropapillary thyroid cancer.

CONCLUSIONS AND RELEVANCE

The incidence of thyroid cancer in patients with MNG and benign FNA is significant. Men and patients in whom the FNA cytology is not reviewed by an experienced cytopathologist may be at an increased risk for an undetected thyroid cancer.

Unanticipated thyroid cancer in patients with substernal goiters: are we underestimating the risk?

BACKGROUND

The rate of unexpected thyroid cancers found at the time of thyroidectomy is thought to be similar in patients with cervical and substernal multinodular goiters (MNGs).

METHODS

The objective of this study was to compare the prevalence of undiagnosed cancer found in patients undergoing a thyroidectomy for a cervical or substernal MNG. We conducted a review of patients with a preoperative diagnosis of an MNG (both cervical and substernal) at a tertiary referral center between 2005 and 2012.

RESULTS

We identified 538 patients who underwent thyroidectomy for an MNG (144 with substernal MNGs and 394 with cervical MNGs). Patients with substernal MNGs were older (59.6 vs. 52.3; p < 0.001), more likely to be men (34 vs. 11.1 %; p < 0.001), and less likely to have a history of radiation exposure to the neck (2.1 vs. 12.4 %; p < 0.001). Thyroid cancer (>1 cm) was found in 13.7 % of substernal MNG specimens and in 6.3 % of cervical MNG specimens (p = 0.003). On multivariate analysis, substernal location [odds ratio (OR) = 2.360; confidence interval (CI), 1.201-4.638] was the only variable independently associated with an unexpected thyroid cancer on surgical pathology.

CONCLUSION

The rate of postoperatively discovered thyroid cancer is significant in patients with substernal MNGs and is increased when compared to patients with cervical MNGs. Surgeons should counsel their patients regarding the possibility of this unexpected result.

Ultrasound-guided methylene blue dye injection for parathyroid localization in the reoperative neck

BACKGROUND

The goal of this study was to review a single institution's experience using intraoperative ultrasound-guided (ioUSG) methylene blue dye injection for the localization and removal of enlarged parathyroid glands in patients with primary hyperparathyroidism and a history of previous neck surgery.

METHODS

We performed a retrospective review of nine consecutive patients who underwent reoperative parathyroidectomy using ioUSG methylene blue dye injection.

RESULTS

All patients had successful resolution of their hyperparathyroidism, with at least a 50 % decrease in intraoperative parathyroid hormone level after resection. One patient had transient recurrent laryngeal nerve paresis. There were no permanent recurrent laryngeal nerve injuries or cases of permanent hypoparathyroidism.

CONCLUSIONS

Blue dye injection is a safe and effective method of localizing diseased parathyroid glands in the reoperative neck.

Utility of serum thyroglobulin measurements after prophylactic thyroidectomy in patients with hereditary medullary thyroid cancer

INTRODUCTION

Prophylactic thyroidectomy can be curative for patients with hereditary medullary thyroid cancer (MTC) caused by RET proto-oncogene mutations. Calcitonin is a sensitive tumor marker used to follow patients. We suggest that thyroglobulin (Tg) levels should also be monitored postoperatively in these patients.

METHODS

We reviewed patients with RET mutations who underwent prophylactic thyroidectomy between 1981 and 2011 at an academic endocrine surgery center. Patients were excluded if they had no postoperative Tg levels recorded.

RESULTS

Of the 22 patients who underwent prophylactic thyroidectomy, 14 were included in the final analysis. The average age at thyroidectomy was 9.8 years (range, 4-29). Tg levels were detectable 1.5 months to 31 years postoperatively in 11 patients (79%), all of whom were <15 years old at thyroidectomy. Median thyroid-stimulating hormone (TSH) was 2.5 mIU/L and 13.4 mIU/L in patients with undetectable and detectable Tg, respectively. Of those with detectable Tg, 5 had cervical ultrasonographic examination: Two showed no residual tissue in the thyroid bed, and 3 showed remnant thyroid tissue.

CONCLUSION

Tg levels can identify patients with remnant thyroid tissue after prophylactic thyroidectomy. Ultrasonography can determine whether thyroid tissue remains posterolaterally that is at risk of MTC recurrence. Maintaining normal TSH may prevent growth of remaining thyroid follicular cells.

Adrenalectomy outcomes are superior with the participation of residents and fellows

BACKGROUND

Adrenalectomy is a complex procedure performed in many settings, with and without residents and fellows. Patients often ask, "Will trainees be participating in my operation?" and seek reassurance that their care will not be adversely affected. The purpose of this study was to determine the association between trainee participation and adrenalectomy perioperative outcomes.

STUDY DESIGN

We performed a cohort study of patients who underwent adrenalectomy from the 2005 to 2011 American College of Surgeons NSQIP database. Trainee participation was classified as none, resident, or fellow, based on postgraduate year of the assisting surgeon. Associations between trainee participation and outcomes were determined via multivariate linear and logistic regression.

RESULTS

Of 3,694 adrenalectomies, 732 (19.8%) were performed by an attending surgeon with no trainee, 2,315 (62.7%) involved a resident, and 647 (17.5%) involved a fellow. The participation of fellows was associated with fewer serious complications (7.9% with no trainee, 6.0% with residents, and 2.8% with fellows; p < 0.001). In a multivariate model, the odds of serious 30-day morbidity were lower when attending surgeons operated with residents (odds ratio = 0.63; 95% CI, 0.45-0.89). Fellow participation was associated with significantly lower odds of overall (odds ratio = 0.51; 95% CI, 0.32-0.82) and serious (odds ratio = 0.31; 95% CI, 0.17-0.57) morbidity. There was no significant association between trainee participation and 30-day mortality.

CONCLUSIONS

In this analysis of multi-institutional data, the participation of residents and fellows was associated with decreased odds of perioperative adrenalectomy complications. Attending surgeons performing adrenalectomies with trainee assistance should reassure patients of the equivalent or superior care they are receiving.

Controversies in familial thyroid cancer 2014

Thyroid cancer is the sixth most common cancer in women, and the majority of patients with thyroid cancer has sporadic disease. However, about 25% of patients with medullary thyroid cancer and 5% with papillary thyroid cancer have familial tumors. Currently, there are numerous controversies regarding the mode of inheritance, tumor behavior, extent of surgical resection for optimal results, coexisting thyroid pathology, risk of other cancers, and extent of postoperative treatment of patients with familial thyroid cancer. This review aimed to give insight to surgeons on this interesting topic.

Impact of race on intraoperative parathyroid hormone kinetics: an analysis of 910 patients undergoing parathyroidectomy for primary hyperparathyroidism

HYPOTHESIS African American patients exhibit different intraoperative parathyroid hormone (IOPTH) profiles than non-African American patients. DESIGN Retrospective review. SETTING University medical center. PATIENTS Nine hundred ten patients who underwent parathyroidectomy for primary hyperparathyroidism between July 2005 and August 2010. INTERVENTIONS All patients underwent preoperative imaging with ultrasonography and sestamibi; operative exploration; and IOPTH measurement at 2 points preexcision and 5 and 10 minutes postexcision. MAIN OUTCOME MEASURES Preexcision and postexcision IOPTH measurements. RESULTS Of the 910 patients, 734 self-reported their race as white (81%); 91, Latino/other (10%); 56, Asian (6%); and 28, African American (3%). African American patients had significantly higher initial preexcision IOPTH levels compared with white patients (348 vs 202 pg/mL; P = .048) and significantly higher 5-minute postexcision IOPTH levels (151 vs 80 pg/mL; P = .01). The 10-minute postexcision IOPTH levels were similar between the 2 groups (52 vs 50 pg/mL). A similar percentage of white and African American patients had a 50% drop in IOPTH level at 10 minutes postexcision. No differences in IOPTH kinetics were observed in the other racial groups examined. CONCLUSIONS African American patients with primary hyperparathyroidism exhibit significantly higher preincision and 5-minute postexcision IOPTH values when compared with white patients. The 10-minute postexcision IOPTH values did not differ between races. The altered IOPTH kinetics identified in African American patients may reflect the severity of biochemical disease but may also be related to genetically predetermined differences in parathyroid hormone metabolism.

New evidence about thyroid cancer prevalence: prevalence of thyroid cancer in younger and middle-aged Japanese population

We have made a cross-sectional investigation of men in the Japanese military for the presence of thyroid abnormalities and thyroid cancer to document the prevalence of thyroid disease in these persons. Six thousand, four hundred and twenty-two Japanese military men and women were screened for thyroid disease by history, physical examination and ultrasound examination. Among them, 6,182 were men 50 years of age, 47 were women 50 years of age, and 149 were men 40 years of age and 44 were women 40 years of age. Among the 50 years old men, thyroid nodules were found in 924 men (14.9%): Nineteen individuals (0.31%) had thyroid cancers ranging from 1 mm to 30 mm in diameter (12.5 mm in mean), pathological TNM staging revealed 7 cases of stage I, 2 cases of stage II and 9 cases of stage III. There was a significant increase in thyroid nodules in 50 years old men compared to that in 40 year old men, but there was no significant difference between men and women (p>0.05). Our data document that the detection rate of thyroid cancer in 50 years old men was 0.31%, and the rate of thyroid nodules increased with age in men, but the frequency of thyroid nodules were similar in men and women of the same age.

Neuroendocrine tumors

Neuroendocrine tumors comprise a broad family of tumors, the most common of which are carcinoid and pancreatic neuroendocrine tumors. The NCCN Neuroendocrine Tumors Guidelines discuss the diagnosis and management of both sporadic and hereditary neuroendocrine tumors. Most of the recommendations pertain to well-differentiated, low- to intermediate-grade tumors. This updated version of the NCCN Guidelines includes a new section on pathology for diagnosis and reporting and revised recommendations for the surgical management of neuroendocrine tumors of the pancreas.

Fluorodeoxyglucose-positron emission tomography scan-positive recurrent papillary thyroid cancer and the prognosis and implications for surgical management

BACKGROUND

To compare outcomes for patients with recurrent or persistent papillary thyroid cancer (PTC) who had metastatic tumors that were fluorodeoxyglucose-positron emission tomography (FDG-PET) positive or negative, and to determine whether the FDG-PET scan findings changed the outcome of medical and surgical management.

METHODS

From a prospective thyroid cancer database, we retrospectively identified patients with recurrent or persistent PTC and reviewed data on demographics, initial stage, location and extent of persistent or recurrent disease, clinical management, disease-free survival and outcome. We further identified subsets of patients who had an FDG-PET scan or an FDG-PET/CT scan and whole-body radioactive iodine scans and categorized them by whether they had one or more FDG-PET-avid (PET-positive) lesions or PET-negative lesions. The medical and surgical treatments and outcome of these patients were compared.

RESULTS

Between 1984 and 2008, 41 of 141 patients who had recurrent or persistent PTC underwent FDG-PET (n = 11) or FDG-PET/CT scans (n = 30); 22 patients (54%) had one or more PET-positive lesion(s), 17 (41%) had PET-negative lesions, and two had indeterminate lesions. Most PET-positive lesions were located in the neck (55%). Patients who had a PET-positive lesion had a significantly higher TNM stage (P = 0.01), higher age (P = 0.03), and higher thyroglobulin (P = 0.024). Only patients who had PET-positive lesions died (5/22 vs. 0/17 for PET-negative lesions; P = 0.04). In two of the seven patients who underwent surgical resection of their PET-positive lesions, loco-regional control was obtained without evidence of residual disease.

CONCLUSION

Patients with recurrent or persistent PTC and FDG-PET-positive lesions have a worse prognosis. In some patients loco-regional control can be obtained without evidence of residual disease by reoperation if the lesion is localized in the neck or mediastinum.

A population-based prospective cohort study of complications after thyroidectomy in the elderly

CONTEXT

Data on the risk of postthyroidectomy complications in elderly patients are sparse, unclear, and conflicting.

OBJECTIVE

We sought to use a population-based cohort to determine whether thyroid operations in the elderly are as safe as those done in younger patients.

DESIGN

This was a prospective cohort study using the American College of Surgeons National Surgical Quality Improvement Program database from 2005 to 2008, with 30-d postoperative follow-up.

SETTING

The American College of Surgeons National Surgical Quality Improvement Program data set contains operative cases from a nationwide sampling of academic and community-based as well as high-volume and low-volume hospitals.

PATIENTS

All thyroidectomy and parathyroidectomy patients reported to the database during the study period were included in the analysis resulting in an experimental cohort of 7915 thyroidectomy cases and a control cohort of 3575 parathyroidectomy cases.

MAIN OUTCOME MEASURES

We aggregated 83 complications into the following outcome measures: urinary tract infection, wound infection, systemic infection, cardiac complications, pulmonary complications, 30-d mortality, and total hospital length of stay.

RESULTS

Increased age is a risk factor for significant pulmonary, cardiac, and infectious complications after thyroidectomy. Elderly patients are twice as likely (odds ratio 2.1, 95% confidence interval 1.4-3.3), and the superelderly are 5 times as likely (odds ratio 4.9, 95% confidence interval 2.5-9.6) to have a complication compared with their young counterparts. Preexisting comorbidities are effect modifiers and increase the risk of complications even further.

CONCLUSIONS

Elderly thyroidectomy patients are at increased risk for major systemic complications. A systematic approach to the care of elderly thyroidectomy patients is necessary to minimize their risk of serious postoperative complications.

MicroRNA expression profiling is a potential diagnostic tool for thyroid cancer

BACKGROUND

Approximately 30% of fine-needle aspiration (FNA) biopsies of thyroid nodules are indeterminate or nondiagnostic. Recent studies suggest microRNA (miRNA, miR) is differentially expressed in malignant tumors and may have a role in carcinogenesis, including thyroid cancer. The authors therefore tested the hypothesis that miRNA expression analysis would identify putative markers that could distinguish benign from malignant thyroid neoplasms that are often indeterminate on FNA biopsy.

METHODS

A miRNA array was used to identify differentially expressed genes (5-fold higher or lower) in pooled normal, malignant, and benign thyroid tissue samples. Real-time quantitative polymerase chain reaction was used to confirm miRNA array expression data in 104 tissue samples (7 normal thyroid, 14 hyperplastic nodule, 12 follicular variant of papillary thyroid cancer, 8 papillary thyroid cancer, 15 follicular adenoma, 12 follicular carcinoma, 12 Hurthle cell adenoma, 20 Hurthle cell carcinoma, and 4 anaplastic carcinoma cases), and 125 indeterminate clinical FNA samples. The diagnostic accuracy of differentially expressed genes was determined by analyzing receiver operating characteristics.

RESULTS

Ten miRNAs showed >5-fold expression difference between benign and malignant thyroid neoplasms on miRNA array analysis. Four of the 10 miRNAs were validated to be significantly differentially expressed between benign and malignant thyroid neoplasms by quantitative polymerase chain reaction (P < .002): miR-100, miR-125b, miR-138, and miR-768-3p were overexpressed in malignant samples of follicular origin (P < .001), and in Hurthle cell carcinoma samples alone (P < .01). Only miR-125b was significantly overexpressed in follicular carcinoma samples (P < .05). The accuracy for distinguishing benign from malignant thyroid neoplasms was 79% overall, 98% for Hurthle cell neoplasms, and 71% for follicular neoplasms. The miR-138 was overexpressed in the FNA samples (P = .04) that were malignant on final pathology with an accuracy of 75%.

CONCLUSIONS

MicroRNA expression differs for normal, benign, and malignant thyroid tissue. Expression analysis of differentially expressed miRNA could help distinguish benign from malignant thyroid neoplasms that are indeterminate on thyroid FNA biopsy.

Controversies in the management of papillary thyroid cancer revisited

The debate on the appropriate treatment of patients with papillary thyroid cancer (PTC) has persisted for several decades. The main controversies focus on the extent of surgery, the timing of central neck dissection, and the indications for radioactive iodine ablation. These controversies continue, for the most part, due to the good prognosis of PTC patients and the questionable effect these treatment modalities have on patient survival. This paper addresses these three controversies and the role of molecular tumor markers in the appropriate treatment selection.

Current status and treatment of primary hyperparathyroidism

Primary hyperparathyroidism (HPT) is diagnosed in approximately 100,000 patients in the US each year, with a 2-3:1 female-to-male distribution. In most cases, occurrence is sporadic rather than familial, and 80% to 85% of cases of sporadic primary HPT are caused by a solitary parathyroid adenoma. The diagnosis is made by hypercalcemia with an inappropriately elevated parathyroid hormone (PTH) level and a 24-hour urine calcium excretion level that is normal or high. Truly asymptomatic primary HPT is rare, as most patients have symptoms or metabolic complications when carefully evaluated by standardized health questionnaires. The National Institutes of Health (NIH) published guidelines in 2002, recommending parathyroidectomy for all symptomatic patients and for asymptomatic patients less than age 50 years or those who cannot participate in medical surveillance. These criteria have been called into question as being too limited, because multiple studies have demonstrated symptomatic and metabolic benefits of parathyroidectomy in "asymptomatic" patients. Given the studies showing an improvement in quality-of-life measures, future risk for developing renal calculi, bone density, cardiovascular health, and risk of death, we believe that virtually all patients with primary HPT should undergo surgical resection. An improvement in preoperative localization studies as well as the development of a rapid intraoperative PTH assay has changed the approach to parathyroid surgery since the 1980s. Because most sporadic primary HPT is caused by a single gland adenoma, our preferred procedure has now changed from a bilateral neck exploration to a focused or unilateral approach, with similar rates of success in patients with a solitary tumor identified preoperatively.

Unique patterns of metastases in common and rare types of malignancy

This review on the unique patterns of metastases by common and rare types of cancer addresses regional lymphatic metastases but also demonstrates general principles by consideration of vital organ metastases. These general features of successfully treated metastases are relationships to basic biological behavior as illustrated by disease-free interval, organ-specific behavior, oligo-metastatic presentation, genetic control of the metastatic pattern, careful selection of patients for surgical resection, and the necessity of complete resection of the few patients eligible for long-term survival after resection of vital organ metastasis. Lymph node metastases, while illustrating these general features, are not related to overall survival because lymph node metastases themselves do not destroy a vital organ function, and therefore have no causal relationship to overall survival. When a cancer cell spreads to a regional lymph node, does it also simultaneously spread to the systemic site or sites? Alternatively, does the cancer spread to the regional lymph node first and then it subsequently spreads to the distant site(s) after an incubation period of growth in the lymph node? Of course, if the cancer is in its incubation stage in the lymph node, then removal of the lymph node in the majority of cases with cancer cells may be curative. The data from the sentinel lymph node era, particularly in melanoma and breast cancer, is consistent with the spectrum theory of cancer progression to the sentinel lymph node in the majority of cases prior to distant metastasis. Perhaps, different subsets of cancer may be better defined with relevant biomarkers so that mechanisms of metastasis can be more accurately defined on a molecular and genomic level.

Thyroid cancer and lymph node metastases

There is considerable controversy about the prognostic implications of lymph node metastases in patients with papillary thyroid cancer and whether patients with papillary thyroid cancer should have a prophylactic or selective central (level VI) neck dissection. Some experts report that a prophylactic ipsilateral neck dissection results in fewer patients having elevated thyroglobulin levels but others do not agree. A comprehensive review of the literature suggests that the presence of macroscopic metastases of papillary thyroid cancer in cervical lymph nodes results in a higher recurrence rate and increased death rate, especially in patients 45 years of age or older, whereas microscopic nodal metastases do not appear to adversely influence survival. Until more information is available we recommend preoperative ultrasonography and a selective ipsilateral neck dissection for patients with papillary thyroid cancer.

Medullary Thyroid Cancer: It is a pain in the neck?

Background: Medullary thyroid cancer (MTC) commonly presents with lymph node (LN) metastases, and has a worse prognosis than papillary thyroid cancer (PTC). Tumor size and LN involvement have been shown to affect stage of disease; however, to our knowledge, ours is the first study that attempts to correlate anterior neck pain on presentation with the extent of disease.

Methods: We performed a retrospective review of patients with MTC who underwent an operation from February 1998 through December 2008. We compared the symptom of anterior neck pain with the pathologic extent of disease. Our control group comprised patients who underwent an operation for PTC. Analysis was performed using the Fisher's exact test and the Mann-Whitney test.

Results: Of the 109 patients with MTC, 50 (46%) met our inclusion criteria. Of the 50 patients with MTC, 11 presented with neck pain, compared to 3 of the 50 patients with PTC (p = 0.041). Of those 11 patients, 9 (82%) had LN involvement on final pathology, as compared with 14 (36%) of the 39 without neck pain (p = 0.014). Of patients with neck pain, 18% were diagnosed at stage I to II and 82% at stage III to IV, compared to 64% at stage I to II and 36% at stage III to IV (p = 0.014).

Conclusions: Our study demonstrates that more patients with MTC present with anterior neck pain than do patients with PTC and that patients with MTC and neck pain have an increased risk of LN metastases. The results of this study suggest that MTC patients, who present with concomitant neck pain, should undergo a total thyroidectomy, prophylactic bilateral central neck dissection, and ipsilateral lateral neck dissection.

Molecular testing for somatic mutations improves the accuracy of thyroid fine-needle aspiration biopsy

Background

Thyroid fine-needle aspiration (FNA) biopsy is indeterminate or suspicious in up to 30% of cases and these patients are commonly subjected to at least a diagnostic hemithyroidectomy. If malignant on histology, a completion thyroidectomy is usually performed, which may be associated with higher morbidity. To determine the clinical utility of genetic testing in thyroid FNA biopsy, we conducted a prospective clinical trial.

Methods

Four hundred seventeen patients with 455 thyroid nodules were enrolled and had genetic testing for common somatic mutations (BRAF, NRAS, KRAS) and gene rearrangements (RET/PTC1, RET/PTC3, RAS, TRK1) by PCR and direct sequencing and by nested PCR, respectively. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of genetic testing in thyroid FNA biopsy were determined based on the histologic diagnosis.

Results

One hundred twenty-five of 455 thyroid nodule FNA biopsies were indeterminate or suspicious on cytologic examination. Overall, 50 mutations were identified (23 BRAF, 4 RET/PTC1, 2 RET/PTC3, 21 NRAS) in the thyroid FNA biopsies. There were significantly more mutations detected in malignant thyroid nodules than in benign (P = 0.0001). For thyroid FNA biopsies that were indeterminate or suspicious, genetic testing had a sensitivity of 12%, specificity of 98%, PPV of 38%, and NPV of 65%.

Conclusions

Genetic testing for somatic mutations in thyroid FNA biopsy samples is feasible and identifies a subset of malignant thyroid neoplasms that are indeterminate or suspicious on FNA biopsy. Genetic testing for common somatic genetic alterations thus could allow for more definitive initial thyroidectomy in those with positive results.

Metastatic papillary thyroid cancer misdiagnosed as non-small [corrected] cell lung cancer

BACKGROUND

Thyroid and lung cancers, two malignancies with similar immunohistological characteristics, have vastly different biologic behaviors and treatment approaches. As thyroid cancers commonly spread to the lungs, metastatic thyroid cancer should be included in the differential diagnosis of a pulmonary lesion or lesions.

SUMMARY

A 54-year-old woman with a remote history of stage IV nonsmall cell lung cancer was found to have FDG avidity in the thyroid and right cervical lymph nodes. Subsequent ultrasonographic findings and FNA cytology led to a total thyroidectomy, bilateral central lymphadenectomy, and right modified radical lymph node dissection for primary thyroid cancer. Reviews and comparisons of the pulmonary and cervical surgical specimens revealed that the patient had been misdiagnosed for the previous 6 years; she had metastatic papillary thyroid cancer to the lung. The patient's original diagnosis of stage IV lung cancer was based upon the original lung biopsy showing positive thyroid transcription factor-1 (TTF-1) immunostaining. The original diagnosis was questioned because of her long survival when she was diagnosed with locally advanced papillary thyroid cancer. Further analyses of the immunohistological characteristics of both surgical specimens--including staining for TTF-1, thyroglobulin, CD57, S-100, and CEA--documented the correct diagnosis.

CONCLUSIONS

A thorough understanding of the natural history and surgical pathology, including immunohistology, of lung and thyroid cancers is necessary for a correct and timely diagnosis and appropriate treatment. Because TTF-1 expression is seen in both thyroid and lung cancers, careful consideration should be given to both malignancies when evaluating patients with thyroid and pulmonary nodules.

Mitogen-inducible gene-6 is a multifunctional adaptor protein with tumor suppressor-like activity in papillary thyroid cancer

CONTEXT

Low tumoral expression of mitogen-inducible gene-6 (Mig-6) is associated with papillary thyroid cancer (PTC) recurrence after thyroidectomy.

OBJECTIVE

We hypothesize that Mig-6 behaves as a tumor suppressor in PTC.

DESIGN

Mig-6 expression and promoter methylation status were compared in 31 PTC specimens with matched normal thyroid tissue from the same patient. The impact of Mig-6 loss and gain of function on nuclear factor κ-light-chain-enhancer of activated B cells (NF-κB) activation, global tyrosine kinase phosphorylation, and cellular invasion was determined in vitro.

RESULTS

Mig-6 protein was abundant in all normal thyroid specimens, whereas 77% of PTC had low Mig-6 expression. Mig-6 promoter methylation was found in 79% of PTC with low Mig-6 expression. Low Mig-6 expression in PTC specimens was associated with low NF-κB activity but high levels of epidermal growth factor receptor (EGFR) and ERK phosphorylation. Mig-6 expression inversely correlated with PTC size but had no association with other clinicopathological variables including age, extrathyroidal extension, lymphovascular invasion, or histological subtype. Mig-6 knockdown in thyroid cancer cell lines resulted in EGFR phosphorylation and diminished NF-κB activity, whereas Mig-6 overexpression had the opposite effects. Mig-6 knockdown activated ErbB2, Met, and Src phosphorylation. Furthermore, Mig-6 regulated ERK phosphorylation independent from its effects on EGFR. Mig-6 knockdown promoted cellular proliferation, as determined by clonogenic survival. Lastly, Mig-6 knockdown increased matrix metalloproteinase-2 and -9 activities and increased cellular invasion.

CONCLUSIONS

Mig-6 has tumor suppressor-like activity in PTC. In vivo studies are required to confirm that Mig-6 is a putative tumor suppressor in PTC, and future studies should investigate the utility of Mig-6 as a diagnostic marker.

A prospective study evaluating the accuracy of using combined clinical factors and candidate diagnostic markers to refine the accuracy of thyroid fine needle aspiration biopsy

BACKGROUND

Approximately 30% of fine needle aspiration biopsies of the thyroid have inconclusive results. We conducted a prospective trial to determine whether clinical and molecular markers could be used in combination to improve the accuracy of thyroid fine needle aspiration biopsy.

METHODS

Clinical, tumor genotyping for common somatic mutations (BRAF V600E, NRAS, KRAS, RET/PTC1, RET/PTC3, and NTRK1), and the gene expression levels of 6 candidate diagnostic markers were analyzed by univariate and multivariate methods in 341 patients to determine whether they could distinguish reliably benign from malignant thyroid neoplasms, and a scoring model was derived.

RESULTS

By a multivariate analysis, fine needle aspiration biopsy cytology classification, the presence of a NRAS mutation, and the tissue inhibitor of metalloproteinase 1 expression level were associated jointly with malignancy. The overall accuracy of the scoring model, including these 3 variables, to distinguish benign from malignant thyroid tumors was 91%, including 67% for the indeterminate and 77% for the suspicious FNA subgroups.

CONCLUSION

Fine needle aspiration biopsy cytology classification, the presence of NRAS mutation, and tissue inhibitor of metalloproteinase 1 messenger RNA expression levels in combination provide a greater diagnostic accuracy than fine needle aspiration biopsy cytology alone to allow selection of more definitive initial operative treatment. The sensitivity of the scoring model, however, was too low to avoid the need for diagnostic thyroidectomies for indeterminate fine needle aspiration biopsy findings.

Identification of differentially expressed microRNA in parathyroid tumors

BACKGROUND

The molecular factors that control parathyroid tumorigenesis are poorly understood. In the absence of local invasion or metastasis, distinguishing benign from malignant parathyroid neoplasm is difficult on histologic examination. We studied the microRNA (miRNA) profile in normal, hyperplastic, and benign and malignant parathyroid tumors to better understand the molecular factors that may play a role in parathyroid tumorigenesis and that may serve as diagnostic markers for parathyroid carcinoma.

METHODS

miRNA arrays containing 825 human microRNAs with four duplicate probes per miRNA were used to profile parathyroid tumor (12 adenomas, 9 carcinomas, and 15 hyperplastic) samples normalized to four reference normal parathyroid glands. Differentially expressed miRNA were validated by real-time quantitative TaqMan polymerase chain reaction (PCR).

RESULTS

One hundred fifty-six miRNAs in parathyroid hyperplasia, 277 microRNAs in parathyroid adenoma, and 167 microRNAs in parathyroid carcinomas were significantly dysregulated as compared with normal parathyroid glands [false discovery rate (FDR) < 0.05]. By supervised clustering analysis, all parathyroid carcinomas clustered together. Three miRNAs (miR-26b, miR-30b, and miR-126*) were significantly dysregulated between parathyroid carcinoma and parathyroid adenoma. Receiver-operating characteristic curve analysis showed mir-126* was the best diagnostic marker, with area under the curve of 0.776.

CONCLUSIONS

Most miRNAs are downregulated in parathyroid carcinoma, while in parathyroid hyperplasia most miRNAs are upregulated. miRNA profiling shows distinct differentially expressed miRNAs by tumor type which may serve as helpful adjunct to distinguish parathyroid adenoma from carcinoma.

One hundred two patients with pheochromocytoma treated at a single institution since the introduction of laparoscopic adrenalectomy

HYPOTHESIS

Pheochromocytoma can be safely treated laparoscopically; "subclinical" pheochromocytoma is increasingly common.

DESIGN

Retrospective review.

SETTING

University hospital.

PATIENTS

Patients undergoing adrenalectomy for pheochromocytoma at our institution in 1994 to 2009.

INTERVENTIONS

Laparoscopic, hand-assisted, and open adrenalectomy.

MAIN OUTCOME MEASURES

Preoperative and postoperative clinical and biochemical data.

RESULTS

One hundred two patients (52 women, 50 men) with pheochromocytoma underwent 108 operations. Ninety-seven operations were laparoscopic; 7, open; and 4, converted from laparoscopic to hand assisted or open. Six operations were bilateral; 3 were subtotal cortex-sparing resections. Thirty-four patients (33%) presented with adrenal incidentaloma and minimal symptoms, 28 within the past decade. Ten patients had paragangliomas, 7 of whom underwent laparoscopic resection. The mean (SD) tumor size was 5.3 (2.8) cm. Seven patients had recurrence requiring reoperation; the mean length of time between initial operation and recurrence was 6 years (range, 6 months to 17 years). There were no perioperative deaths.

CONCLUSIONS

Laparoscopic adrenalectomy can be safely performed for pheochromocytoma in more than 90% of cases. More than one-third of patients presented with subclinical pheochromocytoma. Patients should be followed up closely because recurrence may develop several years after adrenalectomy.

MicroRNA profiling of benign and malignant pheochromocytomas identifies novel diagnostic and therapeutic targets

MicroRNAs (miRNAs) are small RNAs ( approximately 22 bp) that post-transcriptionally regulate protein expression and are found to be differentially expressed in a number of human cancers. There is increasing evidence to suggest that miRNAs could be useful in cancer diagnosis, prognosis, and therapy. We performed miRNA microarray expression profiling on a cohort of 12 benign and 12 malignant pheochromocytomas and identified a number of differentially expressed miRNAs. These results were validated in a separate cohort of ten benign and ten malignant samples using real-time quantitative RT-PCR; benign samples had a minimum follow-up of at least 2 years. It was found that IGF2 as well as its intronic miR-483-5p was over-expressed, while miR-15a and miR-16 were under-expressed in malignant tumours compared with benign tumours. These miRNAs were found to be diagnostic and prognostic markers for malignant pheochromocytoma. The functional role of miR-15a and miR-16 was investigated in vitro in the rat PC12 pheochromocytoma cell line, and these miRNAs were found to regulate cell proliferation via their effect on cyclin D1 and apoptosis. These data indicate that miRNAs play a pivotal role in the biology of malignant pheochromocytoma, and represent an important class of diagnostic and prognostic biomarkers and therapeutic targets warranting further investigation.

'Chromosomal Rainbows' Detect Oncogenic Rearrangements of Signaling Molecules in Thyroid Tumors

Altered signal transduction can be considered a hallmark of many solid tumors. In thyroid cancers the receptor tyrosine kinase (rtk) genes NTRK1 (Online Mendelian Inheritance in Man = OMIM *191315, also known as 'TRKA'), RET ('Rearranged during Transfection protooncogene', OMIM *164761) and MET (OMIM *164860) have been reported as activated, rearranged or overexpressed. In many cases, a combination of cytogenetic and molecular techniques allows elucidation of cellular changes that initiate tumor development and progression. While the mechanisms leading to overexpression of the rtk MET gene remain largely unknown, a variety of chromosomal rearrangements of the RET or NTKR1 gene could be demonstrated in thyroid cancer. Abnormal expressions in these tumors seem to follow a similar pattern: the rearrangement translocates the 3'- end of the rtk gene including the entire catalytic domain to an expressed gene leading to a chimeric RNA and protein with kinase activity. Our research was prompted by an increasing number of reports describing translocations involving ret and previously unknown translocation partners.We developed a high resolution technique based on fluorescence in situ hybridization (FISH) to allow rapid screening for cytogenetic rearrangements which complements conventional chromosome banding analysis. Our technique applies simultaneous hybridization of numerous probes labeled with different reporter molecules which are distributed along the target chromosome allowing the detection of cytogenetic changes at near megabasepair (Mbp) resolution. Here, we report our results using a probe set specific for human chromosome 10, which is altered in a significant portion of human thyroid cancers (TC's). While rendering accurate information about the cytogenetic location of rearranged elements, our multi-locus, multi-color analysis was developed primarily to overcome limitations of whole chromosome painting (WCP) and chromosome banding techniques for fine mapping of breakpoints in papillary thyroid cancer (PTC).

Adrenal incidentaloma: does an adequate workup rule out surprises?

BACKGROUND

Adrenal incidentaloma remains a diagnostic challenge. Despite well-established management guidelines, the long-term results of following these guidelines are unknown. We sought to determine how accurately these guidelines identify functioning incidentalomas and how often these guidelines result in adrenalectomy for benign tumors.

METHODS

We catalogued adrenal incidentalomas from a retrospective review of 500 consecutive adrenalectomies at a single institution. The outcome measures studied were patient demographics, preoperative biochemical analysis, imaging characteristics, tumor size, type of operation performed, and postoperative histologic diagnosis.

RESULTS

Eighty-one of the 500 adrenalectomies performed were for incidentalomas. Size was the only significant characteristic that distinguished cortical cancers from benign adenomas. Only 1 out of 26 functioning tumors was incorrectly identified on preoperative workup. We also found that 25% of cortisol-secreting incidentalomas were cystic, and that benign adenomas accounted for 42% of all tumors resected.

CONCLUSION

Current guidelines accurately predict the functional status of adrenal incidentalomas. Some cystic lesions may be functioning and should therefore be screened for hormonal hypersecretion. However, even with the most up-to-date diagnostic tools available, most adrenal incidentalomas resected are benign tumors.

Age and tumor size predicts lymph node involvement in Hürthle Cell Carcinoma

Introduction: Hürthle cell carcinoma (HCC) is a rare tumor that tends to metastasize to the lymph nodes. Some studies have correlated size of Hürthle cell tumors with the risk of malignancy. Whether the size of HCC correlates with the risk of lymph node (LN) metastases, to our knowledge has not been addressed.

Methods: A retrospective analysis was performed on all patients diagnosed with HCC on final pathology between 1997 and 2008. The tumor size and lymph node status was obtained for each patient. The data were analyzed utilizing Student's t-test and the Fisher's exact test to calculate the two-tailed p-value.

Results: Out of 39 patients diagnosed with HCC 3(8%) had LN metastases; 1 had ipsilateral central LN metastasis and 2 had ipsilateral central and lateral LN metastasis. LN dissection was performed in patients with known metastasis (2 were evident on preoperative ultrasound and 1 intraoperatively). Patients with LN metastasis were older than those without (mean age: 86.7 and 56.4 years, respectively), had larger tumors (mean size: 6 and 4 cm) and were commonly male (2 of 3). No tumor < 5cm presented with lymph node involvement (3/15 with >5cm cancer had node metastasis, 0/24 with <5cm cancer had node metastasis).

Conclusions: Similar to what has been found in patients with papillary thyroid cancer, older male patients with Hürthle cell carcinomas greater than 5cm are more likely to have lymph node metastasis. Our data suggest that these patients may benefit from a prophylactic ipsilateral central neck dissection at the time of their initial operation.

Prior head and neck radiation exposure is not a contraindication to minimally invasive parathyroidectomy

BACKGROUND

Most patients with primary hyperparathyroidism can have a minimally invasive parathyroidectomy based on localization studies showing single-gland disease. In patients with a history of head and neck irradiation, due to the increased risk of multigland disease and risk of concurrent thyroid cancer, minimally invasive parathyroidectomy is considered by some to be a contraindication. We postulated that previous history of head and neck irradiation should not be a contraindication for minimally invasive parathyroidectomy and tested this hypothesis in a prospective cohort of patients undergoing parathyroidectomy for primary hyperparathyroidism.

STUDY DESIGN

We performed a retrospective analysis of a prospective database of 491 consecutive parathyroidectomies performed between May 2005 and May 2007 at a tertiary referral medical center.

RESULTS

Fifty-two (12.6%) patients had a history of head and neck irradiation and 360 (87.4%) had no exposure to radiation. The 2 groups had no significant difference in terms of gender or ethnicity. The radiation group was older, with an average age of 65.1 years versus 58.1 years (p < 0.0009). There was no significant difference in concurrent benign thyroid neoplasm, thyroid cancer, and type of parathyroid disease (single vs multigland) in the 2 groups. There was no significant difference in the operative approach used between the 2 groups (focused vs unilateral or bilateral).

CONCLUSIONS

Head and neck irradiation should not be a contraindication for minimally invasive parathyroidectomy in patients with primary hyperparathyroidism in the setting of preoperative localization studies showing single-gland disease and no concurrent thyroid neoplasm. Furthermore, history of head and neck irradiation is associated with a later age of presentation for parathyroidectomy.

Central neck lymph node dissection for papillary thyroid cancer: the reliability of surgeon judgment in predicting which patients will benefit

BACKGROUND

The role of routine prophylactic central-neck lymph node dissection (CLND) for papillary thyroid cancer (PTC) remains controversial. We perform CLND for PTC only in patients with enlarged nodes as determined by preoperative ultrasound and intraoperative inspection and palpation.

METHODS

We identified all patients with PTC who underwent CLND during thyroidectomy (group 1) at our institution, and then we identified an equivalent number of demographically matched patients who underwent thyroidectomy without CLND (group 2) and compared the outcomes of the 2 groups.

RESULTS

In all, 191 patients were identified for each group; 49/191 (26%) patients in group 1 developed locoregional nodal recurrence (12% central neck and 21% lateral neck), compared with 11/191 (6%) patients in group 2 (3% central neck and 3% lateral neck; P < .05). Overall, 161/191 (84%) patients in group 1 were disease free at last survey, compared with 180/191 (94%) patients in group 2 (P < .05). Transient hypocalcemia was significantly greater in group 1. No difference was found in disease-specific mortality.

CONCLUSION

Surgeon assessment of the central neck compartment is an accurate predictor of which patients with PTC will benefit from CLND. Patients with nonenlarged central neck nodes who undergo total thyroidectomy without CLND have a low risk of developing recurrence.

Percutaneous vertebroplasty for thyroid cancer metastases to the spine

BACKGROUND

Spinal metastases secondary to thyroid cancer of follicular and parafollicular cell origin are uncommon but may require stabilization of the compromised vertebrae to prevent fracture with spinal cord injury. Such treatment may also relieve pain and improve survival and quality of life.

SUMMARY

Percutaneous vertebroplasty (PV) is a minimally invasive, radiologically guided procedure whereby bone cement is injected into a structurally weakened vertebra to provide immediate stability. The authors present two cases of thyroid cancer with spinal metastases. Both patients successfully underwent PV. Following PV, the patients experienced significant pain relief with immediate reduction in analgesic requirements and improvement in other symptoms. Both were able to return to their daily activities.

CONCLUSION

PV is a minimally invasive spinal procedure and should be considered for patients with metastatic thyroid cancer with spinal metastases.

Antineoplastic effects of decitabine, an inhibitor of DNA promoter methylation, in adrenocortical carcinoma cells

HYPOTHESES

Decitabine recovers expression of silenced genes on chromosome 11q13 and has antineoplastic effects in adrenocortical carcinoma (ACC) cells.

DESIGN

NCI-H295R cells were treated with decitabine (0.1-1.0 microM) over 5 days. Cells were evaluated at 24-hour intervals for the effects of decitabine on ACC cell proliferation, cortisol secretion, and cell invasion. Expression was quantified for 6 genes on 11q13 (DDB1, MRPL48, NDUFS8, PRDX5, SERPING1, and TM7SF2) that were previously shown to be underexpressed in ACC.

SETTING

Academic research. Study Specimen Human ACC cell line.

MAIN OUTCOME MEASURES

Adrenocortical carcinoma cell proliferation, cortisol secretion, and cell invasion were measured using immunometric assays. Quantitative reverse transcription-polymerase chain reaction was used to measure gene expression relative to GAPDH.

RESULTS

Decitabine inhibited ACC cell proliferation by 39% to 47% at 5 days after treatment compared with control specimens (P < .001). The inhibitory effect was cytostatic, time dependent, and dose dependent. Decitabine decreased cortisol secretion by 56% to 58% at 5 days after treatment (P = .02) and inhibited cell invasion by 64% at 24 hours after treatment (P = .03). Of 6 downregulated genes on 11q13, decitabine recovered expression of NDUFS8 (OMIM 602141) (P < .001) and PRDX5 (OMIM 606583) (P = .006).

CONCLUSIONS

Decitabine exhibits antitumoral properties in ACC cells at clinically achievable doses and may be an effective adjuvant therapy in patients with advanced disease. Decitabine recovers expression of silenced genes on 11q13, which suggests a possible role of epigenetic gene silencing in adrenocortical carcinogenesis.

Central neck lymph node dissection for papillary thyroid cancer: comparison of complication and recurrence rates in 295 initial dissections and reoperations

BACKGROUND

The American Thyroid Association recently changed its management guidelines for papillary thyroid cancer (PTC) to include routine central neck lymph node dissection (CLND) during thyroidectomy. We currently perform CLND during thyroidectomy only if enlarged central nodes are detected by palpation or ultrasonography; we perform CLND in the reoperative setting for recurrence in previously normal-appearing or incompletely resected nodes. Critics of this approach argue that reoperative CLND has higher complication and recurrence rates than initial CLND. We sought to test this argument, using it as our hypothesis.

DESIGN

Retrospective review.

SETTING

University hospital.

PATIENTS

All patients undergoing CLND for PTC between January 1, 1998, and December 31, 2007.

INTERVENTIONS

Thyroidectomy and CLND.

MAIN OUTCOME MEASURES

Complications (neck hematoma, recurrent laryngeal nerve injury, and hypoparathyroidism) and recurrence of PTC.

RESULTS

Altogether, 295 CLNDs were performed: 189 were initial operations and 106 were reoperations. The rate of transient hypocalcemia (41.8% vs 23.6%) was significantly higher in patients undergoing initial CLND compared with those undergoing reoperative CLND. Rates of neck hematoma (1.1% vs 0.9%), transient hoarseness (4.8% vs 4.7%), permanent hoarseness (2.6% vs 1.9%), and permanent hypoparathyroidism (0.5% vs 0.9%) were not different between initial and reoperative CLND. In addition, recurrence rates in the central (11.6% vs 14.1%) and lateral (21.7% vs 17.0%) compartments were not different between the 2 groups.

CONCLUSIONS

Reoperative CLND for PTC has a lower rate of temporary hypocalcemia, the same rate of other complications, and the same rate of recurrence compared with initial CLND. Choosing to observe nonenlarged central neck lymph nodes for PTC does not result in increased complications or recurrence if reoperation is required.

Clinical spectrum of pheochromocytoma

BACKGROUND

Pheochromocytomas vary in presentation, tumor size, and in catecholamine production. Whether pheochromocytoma size correlates with hormone levels, clinical presentation, and perioperative complications is not known. The goal of this study was to determine if tumor size and hormone level correlate according to the clinical presentation at diagnosis.

STUDY DESIGN

We retrospectively analyzed all patients who underwent an adrenalectomy with a diagnosis of a pheochromocytoma from February 1996 to October 2008. We grouped patients according to their clinical presentation at diagnosis (routine biochemical screening, incidentaloma, classic symptoms, pheochromocytoma crisis) and obtained preoperative radiographic tumor size and catecholamine hormone levels. ANOVA was used for the group effects and the Kruskal-Wallis rank test was used for pairwise comparison between groups with the Sidak/Bonferroni method for multiplicity adjustment according to age, tumor size, and hormone level. The Pearson correlation coefficient was then calculated to determine if hormone level correlated with tumor size.

RESULTS

Eighty-one of 107 patients had data available for complete analysis. The average age at diagnosis for all patients was 47.1 years, and the average tumor size was 4.9 cm. The average highest hormone ratio among all patients was 27.4. Tumor size and hormone ratio levels differed among all groups (p < or = 0.03). A direct correlation (p = 0.014) was apparent between tumor size and hormone level. Complication rates also differed among the four groups of patients (p < or = 0.02).

CONCLUSIONS

Our study showed that tumor size directly correlates with hormone level. Smaller tumors tend to secrete lower levels of catecholamines, but larger tumors have a wider variation in secretory potential. Larger tumors, however, produced the highest hormone ratios.

Diagnostic markers and prognostic factors in thyroid cancer

There has been considerable progress identifying biomarkers in thyroid tumors that improve the accuracy of fine-needle aspiration biopsy and also help predict tumor aggressiveness or behavior. In this review we address both the clinical potential of molecular biomarkers and their usefulness, based on the most recent literature. We describe the current best clinical staging systems and the common somatic mutations in thyroid cancer. The BRAF mutation is the most common mutation in papillary thyroid cancer and has recently been reported to be associated with disease aggressiveness; it is also an independent predictor of tumor behavior. Combined testing of RET/PTC, NTRK, RAS and PAX8–PPARγ, which are mutually exclusive mutations, helps improve the accuracy of fine-needle aspiration biopsy. Gene-expression profiling studies have identified a variety of potential molecular markers to help distinguish benign from malignant thyroid neoplasms. Expression analysis of differentially expressed microRNAs also appears to be a promising diagnostic approach for distinguishing benign from malignant thyroid neoplasm. It is especially useful for indeterminate nodules by fine-needle aspiration biopsy.