Controversies in the management of thyroid nodule

[Definitive treatment of Graves' disease in children]

BACKGROUND

Hyperthyreoidism due to Graves' disease is a rare disorder in pediatric practice. There is 2 treatment options in Graves' disease: medical treatment and definitive treatment, including surgery and radioactive iodine. Each method has its advantages and disadvantages. If medical therapy is ineffective the choice between radical treatment method is raised: radioactive iodine or total thyroidectomy. In this research we analyze treatment outcomes in pediatric Graves' disease patients after different radical treatment methods.

AIM

Comparative analysis of radical treatment outcomes in pediatric patients with Graves' disease.

MATERIALS AND METHODS

Retrospective and prospective one-center research of 122 patients with Graves' disease after radical treatment (between 2016 and 2021)RESULTS: The mean age was 13.5±3,5 year at the moment of examination. Patients were divided into 2 groups due to the radical treatments method: 1 group (n=60) were children after surgical treatment, 2 group (n=62) - after radioactive iodine. The mean dose of medical treatment in these groups did not reliably differ (p=0,06), duration of the medical treatment was reliably longer in patients after radioactive iodine (p=0,024). Graves' orbitopathy was diagnosed in 58 patients (47,5%) and met equally often in both groups, but active stage of Graves' orbitopathy was diagnosed only in patients from the 1st group. Thyroid size was reliable bigger in patients from the 1st group (p=0,004), and thyroid gland nodes were diagnosed only in patients from 1st group (p=0,0007).

CONCLUSION

RI can be considered an effective and safe treatment for GD. The effectiveness of RI depends on the volume of the thyroid gland; according to the results of the constructed ROC curve, the risk of repeated RI is higher with a volume of more than 55 cm3. Also radioactive iodine is undesirable if there is signs of ophatalmopathy due to its possible deterioration. According to the results of the study hypoparathyroidism after surgical treatment was diagnosed in 20%, recurrent laryngeal nerve injury was diagnosed after surgical treatment in 5% of patients. In patients with identified nodular goiter according to the results of ultrasound, surgical treatment is preferable due to the impossibility of excluding thyroid cancer.

Efficacy of dual use of Tc-99m-pertechnetate and Tc-99m-tetrofosmin scintigraphy for the assessment of thyroid nodules

INTRODUCTION

Radioisotope methods have shown to be useful in the non-invasive diagnosis of thyroid nodules over the past years. The present prospective study aims to evaluate the efficacy of gamma imaging using single and dual tracer using Tc-99m pertechnetate and Tc-99m tetrofosmin for evaluation and management of thyroid nodules.

METHODS

Dynamic (perfusion) imaging was performed after injecting 148-185 MBq (4-5 mCi) of Tc-99m pertechnetate followed by static imaging. A second, dynamic (perfusion) imaging study within same week was performed with 296-370MBq (8-10mCi) of Tc-99m tetrofosmin on same group of patients followed by early and delayed images. Results of radionuclide perfusion scan from both studies were compared qualitatively with postsurgical histopathology or fine needle aspiration cytology (FNAC).

RESULTS

Total 65 nodules in 50 patients were included in the study. With single tracer, the specificity and accuracy of Tc-99m pertechnetate was 23% and 45% and for Tc-99m tetrofosmin scan was 40% and 49%. When dual tracers were evaluated for the same group of patients, the specificity was 56% and accuracy was 55%.

CONCLUSION

Dual Tracer technique with Tc-99m pertechnetate and Tc-99m tetrofosmin could be helpful in selecting nodules need surgical intervention. This technique can be used for convenient and rapid diagnostic evaluation of thyroid nodules non-invasively. We suggest a combination of fine needle aspiration biopsy and dual use of Tc-99m-pertechnetate and Tc-99m-tetrofosmin as a routine diagnostic approach to thyroid nodules.

High Rates of Underlying Thyroid Cancer in Patients Undergoing Thyroidectomy for Hyperthyroidism

BACKGROUND

The rate of thyroid cancer in patients with hyperthyroidism is reported to be rare, and patients with toxic thyroid nodules do not routinely undergo fine-needle aspiration (FNA) to evaluate for malignancy. However, higher rates of malignancy in hyperthyroid patients may exist than previously reported. This study examines the rate of malignancy in patients with hyperthyroidism who have undergone thyroidectomy.

METHODS

A retrospective review of prospectively collected data of 138 patients with hyperthyroidism who underwent thyroidectomy at a single institution was performed. Patients were divided into three groups: Graves' disease (n = 80), toxic multinodular goiter (n = 46), and toxic solitary nodule (n = 12). Patients with previous thyroid surgery were excluded from the study. All patients had biochemical confirmation of hyperthyroidism with thyroid-stimulating hormone <0.1 mIU/L and clinical diagnosis by a referring physician.

RESULTS

Of 138 patients, 22% (31/138) were found to have malignancy on final pathology. The breakdown of malignancy by hyperthyroid condition was as follows: 16% in Graves' disease, 24% in toxic multinodular goiter patients, and 50% in toxic solitary nodule patients.

CONCLUSIONS

There is a clinically significant rate of malignancy seen in patients who undergo thyroidectomy for hyperthyroidism. Patients with distinct thyroid nodules in the presence of hyperthyroidism may have the highest rates of malignancy and should undergo appropriate workup with ultrasound and FNA to exclude underlying malignancy. In cases with suspicious ultrasound features and/or FNA cytopathology, surgical treatment should be considered as initial management.

In-Depth Proteomics Analysis to Identify Biomarkers of Papillary Thyroid Cancer Patients Older Than 45 Years with Different Degrees of Lymph Node Metastases

PURPOSE

Investigations of the molecular mechanisms underlying the metastatic phenotype of papillary thyroid cancer (PTC) and identification of novel candidate biomarkers to better predict PTC metastasis are urgently required.

EXPERIMENTAL DESIGN

Tandem mass tag-based quantitative proteomics approach is used to identify differentially expressed proteins (DEPs) in PTC tumorous tissues with different degrees of lymph node metastases (LNMs). Furthermore, DEPs and their clinical significance are analyzed in another independent Cancer Genome Atlas dataset.

RESULTS

The protein profiles among tumorous tissues with different degrees of LNMs are clearly distinguished, while the protein profiles in normal tissues are remarkably similar. DEPs in tumorous tissues are mostly enriched in the categories associated with pathological hallmarks of cancer, including extracellular matrix, metabolism, and cell growth. The expression patterns of six DEPs (LAMC2, LAMB3, ATP5A1, MYO1G, S100A4, and FAS) are confirmed by the Cancer Genome Atlas dataset. Additionally, the elevated expression of LAMC2 and MYO1G mRNA levels in tumorous tissues show a positive relationship with unfavorable variables, including larger tumor size, LNMs, high AJCC staging, BRAF^V600E mutation, and poor prognosis.

CONCLUSIONS AND CLINICAL RELEVANCE

LAMC2 and MYO1G are identified as potential candidate biomarkers for the prediction of PTC metastasis and prognosis.

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

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

Outcomes of Capsular Dissection Technique with Use of Bipolar Electrocautery in Total Thyroidectomy: A Rural Tertiary Center Experience

INTRODUCTION

Total thyroidectomy is one of the most routinely performed head and neck surgical procedures with extremely low mortality. This procedure has been associated with two major complications such as recurrent laryngeal nerve injury and hypocalcaemia due to parathyroid insufficiency. The use of bipolar electrocautery has not been widely accepted in view of thermal damage to adjacent structures.

AIM

To study the outcomes and complications of capsular dissection technique along with use of bipolar electrocautery in total thyroidectomy.

MATERIALS AND METHODS

The study was conducted from May 2013 to May 2016. The study was performed at Department of ENT Otorhinolayngology, DM WIMS Hospital, Wayanad, Kerala, India. This retrospective descriptive study analysed the outcome of 130 patients who underwent total thyroidectomy by capsular dissection technique along with use of bipolar electrocautery for cauterization of vascular pedicles, at our institution over a 3 year period.

RESULTS

The incidence of permanent unilateral vocal cord palsy was 1.5% and permanent hypocalcaemia was 2.3%. There was no case of haemorrhage or haematoma in this study.

CONCLUSION

Total thyroidectomy by capsular dissection technique along with the use of bipolar electrocautery has very low incidence of recurrent laryngeal nerve and parathyroid injury, as per our data. Hence, we recommend this technique along with routine use of bipolar electrocautery for total thyroidectomy.

What is the Minimal Surgery for Papillary Thyroid Carcinoma?

Although thyroid surgery for treatment of papillary thyroid carcinoma (PTC) has been practiced for more than 100 years, there is still controversy regarding the minimal surgery needed for cure. The main reason for this controversy is lack of prospective randomized trials. The data accumulated in the last four decades indicate that hemithyroidectomy can be sufficient and safely practiced in low-risk patients with PTC. Patients <45 years of age with a single tumor less than 2 cm, with no lymphatic spread, and in the absence of other risk factors, can be equally managed by hemithyroidectomy or total thyroidectomy. A slight increase in the risk of vocal cord paralysis and hypocalcemia after total thyroidectomy suggests that hemithyroidectomy is appropriate for the management of patients with stage T1 disease. Any choice regarding the extent of surgery should be made with the patient and his family and in a multidisciplinary setup, which has been shown to improve decision-making procedures before the operation and during follow-up.

Bioinformatics analyses of significant prognostic risk markers for thyroid papillary carcinoma

This study was aimed to identify the prognostic risk markers for thyroid papillary carcinoma (TPC) by bioinformatics. The clinical data of TPC and their microRNAs (miRNAs) and genes expression profile data were downloaded from The Cancer Genome Atlas. Elastic net-Cox's proportional regression hazards model (EN-COX) was used to identify the prognostic associated factors. The receiver operating characteristic (ROC) curve and Kaplan-Meier (KM) curve were used to screen the significant prognostic risk miRNA and genes. Then, the target genes of the obtained miRNAs were predicted followed by function prediction. Finally, the significant risk genes were performed literature mining and function analysis. Total 1046 miRNAs and 20531 genes in 484 cases samples were identified after data preprocessing. From the EN-COX model, 30 prognostic risk factors were obtained. Based on the 30 risk factors, 3 miRNAs and 11 genes were identified from the ROC and KM curves. The target genes of miRNA-342 such as B-cell CLL/lymphoma 2 (BCL2) were mainly enriched in the biological process related to cellular metabolic process and Disease Ontology terms of lymphoma. The target genes of miRNA-93 were mainly enriched in the pathway of G1 phase. Among the 11 prognostic risk genes, v-maf avian musculoaponeurotic fibrosarcoma oncogene homologue F (MAFF), SRY (sex-determining region Y)-box 4 (SOX4), and retinoic acid receptor, alpha (RARA) encoded transcription factors. Besides, RARA was enriched in four pathways. These prognostic markers such as miRNA-93, miRNA-342, RARA, MAFF, SOX4, and BCL2 may be used as targets for TPC chemoprevention.

Role of cytological characteristics of benign thyroid nodules on effectiveness of their treatment with levothyroxine

INTRODUCTION

Levothyroxine (LT4) therapy has been used for the treatment of euthyroid nodular goiter, but there are controversial results about its usefulness. We aimed to evaluate the possible role of benign nodules' cytological characteristics in response to LT4 therapy.

MATERIAL AND METHODS

In total, 93 patients with 128 nodules were included in the study; 74 of the nodules were treated with LT4 (group 1), and 54 of them had no medication (group 2). The subgroups consisted of adenomatous nodules, colloid nodules and cystic nodules.

RESULTS

In group 1, mean thyroid volume and mean nodule volume were reduced significantly (p = 0.002 and p = 0.022, respectively) with low-normal level thyrotropin (TSH) suppression (between 0.3 mIU/ml and 1.0 mIU/ml), while there were no significant changes in group 2. When we evaluated changes of the initial and last nodule volumes in cytological subgroups, only colloid nodules in group 1 had significant reduction (p = 0.040) and the others had no significant changes. By omitting the colloid nodules, when the other nodules were revaluated, there were no significant changes in either group.

CONCLUSIONS

On the basis of these results, obtained from a large sample of Anatolian patients, it is possible that LT4 therapy leads to significant reductions of both thyroid volume and nodule size in colloid nodules, but not in other kinds of benign nodules.

Urokinase plasminogen activator and its inhibitor type-1 as prognostic factors in differentiated thyroid carcinoma patients

OBJECTIVE

To investigate the prognostic value of urokinase-type plasminogen activator (uPA) and its inhibitor, type-1 plasminogen activator inhibitor (PAI-1), in differentiated thyroid cancer.

STUDY DESIGN

Prospective cohort study.

SETTING

University hospital.

SUBJECTS AND METHODS

Cytosolic concentrations of uPA and PAI-1 were determined in 105 patients with differentiated thyroid carcinoma and normal matched tissues using an enzyme-linked immunoassay (ELISA).

RESULTS

Both uPA and PAI-1 concentrations were significantly higher in differentiated thyroid tumors (uPA = 0.509 ± 0.767 and PAI-1 = 6.337 ± 6.415 ng/mg) compared to normal tissues (uPA = 0.237 ± 0.051, P < .001; PAI-1 = 2.368 ± 0.418 ng/mg, P < .001). uPA and PAI-1 were significantly higher if extrathyroidal invasion (uPA, P = .015; PAI-1, P < .001) or distant metastasis (PAI-1 P < .001) was present, as well as in tumors whose size exceeded 1 cm in diameter (uPA, P = .002; PAI-1, P = .001). Survival analysis revealed the significant impact of both uPA and PAI-1 on progression-free survival (PFS) (82.22 vs 49.478 months for patients with low and high uPA, respectively, P < .001; 87.068 vs 44.964 months for patients with low and high PAI-1, respectively, P < .001). Univariate analysis showed that gender, tumor size, tumor grade, extrathyroid invasion, local lymph node involvement, distant metastasis, uPA, and PAI-1 were significant predictors of PFS. However, multivariate analysis identified only distant metastasis and tumor tissue uPA and PAI-1 as independent prognostic factors.

CONCLUSION

These findings indicate that high uPA and PAI-1 levels represent independent unfavorable prognostic factors in patients with differentiated thyroid carcinoma.

Multifocal Micropapillary Thyroid Cancer: A New Indication for Total Thyroidectomy?

American Thyroid Association guidelines recommend total thyroidectomy (TT) for thyroid cancers 1 cm or greater. Liberal use of neck sonography has resulted in an increased incidence of papillary cancers detected at earlier stages with approximately half at the micropapillary level and occasionally multifocal. Concerns regarding the safety of routine TT, especially in young patients with favorable cancers, and the clinical significance of detected multifocal micropapillary cancers have been raised. Records of 516 consecutively treated patients with thyroid cancer were reviewed. A subset of 269 cases with well-differentiated papillary thyroid cancer (WDPTC) confined within the capsule of the involved lobe undergoing TT was analyzed. Patients were stratified according to age, tumor size, evidence of ipsilateral multifocality, and presence or absence of contralateral nonpalpable malignancy. Overall contralateral histologic malignancy was demonstrated in 46.4 per cent (125 of 269). The incidence was 34 per cent (30 of 88) of subcentimeter (less than 1 cm) tumors and significantly increased to 52 per cent (95 of 181) in tumors 1 cm or greater ( P = 0.006). This incidence significantly approached 76 per cent (13 of 17) in subcentimeter but multifocal tumors when 45 years or older ( P = 0002). One patient developed permanent hypocalcemia (0.4%). There were no recurrent nerve injuries. The incidence of bilateral cancer was significant in 1-cm or greater WDPTC. Patients with subcentimeter multifocal tumors, when older than 45 years, were even at higher risk for bilateral cancer. Because TT is advocated for patients with WDPTC 1 cm or greater, it should also be considered in those older than 45 years with ipsilateral multifocal micropapillary cancers, because it can be performed safely.

S100-A10, thioredoxin, and S100-A6 as biomarkers of papillary thyroid carcinoma with lymph node metastasis identified by MALDI imaging

In papillary thyroid carcinoma (PTC), metastasis is a feature of an aggressive tumor phenotype. To identify protein biomarkers that distinguish patients with an aggressive tumor behavior, proteomic signatures in metastatic and non-metastatic tumors were investigated comparatively. In particular, matrix-assisted laser desorption/ionization (MALDI) imaging mass spectrometry (IMS) was used to analyze primary tumor samples. We investigated a tumor cohort of PTC (n = 118) that were matched for age, tumor stage, and gender. Proteomic screening by MALDI-IMS was performed for a discovery set (n = 29). Proteins related to the discriminating mass peaks were identified by 1D-gel electrophoresis followed by mass spectrometry. The candidate proteins were subsequently validated by immunohistochemistry (IHC) using a tissue microarray for an independent PTC validation set (n = 89). In this study, we found 36 mass-to-charge-ratio (m/z) species that specifically distinguished metastatic from non-metastatic tumors, among which m/z 11,608 was identified as thioredoxin, m/z 11,184 as S100-A10, and m/z 10,094 as S100-A6. Furthermore, using IHC on the validation set, we showed that the overexpression of these three proteins was highly associated with lymph node metastasis in PTC (p < 0.005). For functional analysis of the metastasis-specific proteins, we performed an Ingenuity Pathway Analysis and discovered a strong relationship of all candidates with the TGF-β-dependent EMT pathway. Our results demonstrated the potential application of the MALDI-IMS proteomic approach in identifying protein markers of metastasis in PTC. The novel protein markers identified in this study may be used for risk stratification regarding metastatic potential in PTC.

Expression of the membrane mucins MUC4 and MUC15, potential markers of malignancy and prognosis, in papillary thyroid carcinoma

BACKGROUND

Papillary thyroid carcinoma (PTC) is the most frequent carcinoma of the thyroid gland and has a relatively good prognosis. However, it is important to identify PTC characteristics that indicate high risk for recurrence and metastasis. To date, overexpression of the membrane mucin, MUC1, has been investigated as a key molecular event in the pathogenesis of aggressive PTC. However, other membrane-associated mucins, matrix metalloproteinase-13 (MMP-13) and tissue inhibitor of metalloproteinase-13 (TIMP-3), have not been studied yet. The aim of this study was to evaluate the expression levels of MUC4, MUC15, MMP-13, and TIMP-3 and their prognostic significance in PTC.

METHODS

We analyzed MUC4, MUC15, MMP-13, and TIMP-3 expression in 10 PTC and 10 normal thyroid tissue samples using real-time reverse transcription-polymerase chain reaction. Tissue array blocks were obtained from 98 PTC cases. Tumor regions and nontumor regions were analyzed in tissue array blocks and immunohistochemistry studies were conducted using sectioned slides. Semiquantitative scores were correlated with clinicopathological factors of 98 PTC patients.

RESULTS

MUC4- and MUC15-specific mRNA was increased by 78-fold and 4.75-fold, respectively, in PTC samples compared with normal thyroid tissues. MMP-13 and TIMP-3 gene expression levels were decreased by approximately 0.39-fold and 0.53-fold, respectively. By immunohistochemistry, MUC4 and MUC15 expression levels were increased in PTC samples compared with normal thyroid tissues (p < 0.001). MMP-13 and TIMP-3 expression levels were decreased in PTC samples compared with normal thyroid tissues (p < 0.001). High MUC4 scores were significantly correlated with small tumor size and papillary thyroid microcarcinoma subtype. High MUC15 scores were significantly correlated with age (≥45 years), distant metastasis, and multifocality.

CONCLUSIONS

MUC4 and MUC15 were overexpressed in PTC, and high MUC15 expression was associated with high malignant potential. MUC15 may serve as a prognostic marker and potential novel therapeutic target in PTC.

Papillary thyroid microcarcinoma: extrathyroidal extension, lymph node metastases, and risk factors for recurrence in a high prevalence of goiter area

BACKGROUND

Although papillary thyroid microcarcinoma (PTMC) is diagnosed with increasing frequency, the best therapeutic option and follow-up protocol have not been established yet, especially in the case of incidental diagnosis. We reviewed our series of patients with PTMC to determine risk factors for recurrence in an area where there is a high prevalence of goiter.

METHODS

The medical records of all patients who underwent thyroidectomy with a final pathology report of PTMC between October 2002 and June 2007 were reviewed. PTMC was defined as a papillary thyroid carcinoma 10 mm or less in diameter. Follow-up evaluation was obtained by outpatient consultation and/or telephone interview.

RESULTS

In a series of 2,220 patients who underwent thyroidectomy for a thyroid carcinoma, 933 had a PTMC. Diagnosis was incidental in 704 patients (75.5%). Upon multivariate analysis, tumor size, nonincidental diagnosis, and neck node metastases at diagnosis were independent risk factors for extracapsular spread (ECS), while ECS, multifocal disease, and number of removed lymph nodes were independent risk factors for lymph node metastases at diagnosis. Follow-up evaluation was completed in 287 patients, 9 (3.1%) of whom experienced recurrence. The number of removed and metastasized nodes at first operation and the length of the follow-up were independent risk factors for recurrent disease.

CONCLUSIONS

Incidental diagnosis of PTMC is frequent in a high prevalence of goiter area. PTMC shows a variable degree of aggressiveness. Management protocols should be based on patient- and tumor-related prognostic factors, as for larger tumors.

Management of thyroid nodules and surgery for differentiated thyroid cancer

The incidence of well-differentiated thyroid cancer has seen a worldwide increase in the last three decades. Whether this is due to a 'true increase' in incidence or simply increased detection of otherwise subclinical disease remains unclear. The treatment of thyroid cancer revolves around appropriate surgical intervention, minimising complications and the use of adjuvant therapy in select circumstances. Prognostic features and risk stratification are crucial in determining the appropriate treatment. There continues to be considerable debate in several aspects of management in these patients. Level 1 evidence is lacking, and there are limited prospective data to direct therapy, hence limiting decision-making to retrospective analyses, treatment guidelines based on expert opinion and personal philosophies. This overview focuses on the major issues associated with the investigation of thyroid nodules and the extent of surgery. As overall survival in well-differentiated thyroid cancer exceeds 95%, it is important to reduce over-treating the large majority of patients, and focus limited resources on high-risk patients who require aggressive treatment and closer attention. The onus is on the physician to avoid treatment-related complications from thyroid surgery and to offer the most efficient and cost-effective therapeutic option.

Controversies and challenges in the management of well-differentiated thyroid cancer

The incidence of well-differentiated thyroid cancer has seen a worldwide increase in the last three decades, although whether this is due to a 'true increase' in incidence or simply increased detection of otherwise subclinical disease remains undetermined. Nonetheless, this rising incidence has fuelled an interest in early diagnosis, treatment and follow-up of thyroid cancer along with greater public awareness. The treatment of thyroid cancer revolves around appropriate surgical intervention, minimising complications and the use of adjuvant therapy in select circumstances. Prognostic features and risk stratification are crucial in determining the appropriate treatment. There continues to be considerable debate in several aspects of management in these patients, and there is limited prospective data to direct therapy, hence limiting decision-making to retrospective analyses, treatment guidelines based on expert opinion and personal philosophies. The major controversies are related to diagnostic work-up, extent of surgery and postoperative management including the role of radioactive iodine. There are also differences in opinion regarding management of nodal metastases and follow-up protocols. As overall survival in well-differentiated thyroid cancer exceeds 95%, it is important to reduce over-treating the large majority of patients, and focus limited resources on high-risk patients who require aggressive treatment and closer attention. There needs to be a concerted effort on the part of a multidisciplinary team to recognise the nuances in treating well-differentiated thyroid cancer.

Revision thyroid surgery - technical considerations

Reoperative thyroid surgery is a technical challenge with a high incidence of complications and recurrent disease. It requires a thorough understanding of the anatomy and biology of the disease process, expertise in surgical technique, and avoidance of complications related to recurrent laryngeal nerve and parathyroid glands. Preoperative evaluation includes review of previous surgical procedures and pathology reports and evaluation of the extent of the disease with appropriate imaging studies. Preoperative evaluation of the vocal cord and vocal cord function is vitally important. Postoperative adjuvant treatment with radioactive iodine or external radiation therapy should be considered in selected individuals. Proper histologic evaluation of the recurrent thyroid tumor is important, to rule out poorly differentiated thyroid carcinoma. Despite good surgical resection, the incidence of local recurrence in the central compartment is high in patients undergoing reoperative thyroid surgery.

Selective surgical management of well-differentiated thyroid cancer

There has been a rapid rise in the incidence of thyroid cancer in the United States, along with more incidentalomas of the thyroid. Treatment of thyroid cancer revolves around appropriate surgical intervention, minimizing complications, and the use of adjuvant therapy in select circumstances. Prognostic features and risk-group analysis are crucial in determining the appropriate treatment. Thyroid cancers are divided into low-, intermediate-, and high-risk groups. Surgical treatment should adhere to the risk-group analysis. The prognostic features in thyroid cancer are age, gender, size and grade of the tumor, extrathyroidal extension, and completeness of resection. The patient presenting with extrathyroidal extension needs extra attention in the operating room to remove all gross tumor during the initial surgical procedure to avoid future recurrences. Nodal metastasis generally has minimal implications; however, in older patients and those with poorly differentiated histology, it has major implications. Grading of the tumor is important, especially for understanding the poorly differentiated varieties of thyroid cancer, such as tall cell and insular. These patients do not respond well to RAI and are best followed with a PET scan. Overall survival in patients with well-differentiated thyroid cancer exceeds 95%.

Management of the solitary thyroid nodule

Thyroid nodules are common, with up to 8% of the adult population having palpable nodules. With the use of ultrasound, up to 10 times more nodules are likely to be detected. Increasing numbers of nodules are being detected serendipitously because of the rising use of imaging to investigate unrelated conditions. The primary aim in investigating a thyroid nodule is to exclude the possibility of malignancy, which occurs in about 5% of nodules. This begins with a thorough history, including previous exposure to radiation and any family history of thyroid cancer or other endocrine diseases. Clinical examination of the neck should focus on the thyroid nodule and the gland itself, but also the presence of any cervical lymphadenopathy. Biochemical assessment of the thyroid needs to be followed by thyroid ultrasound, which may demonstrate features that are associated with a higher chance of the nodule being malignant. Fine-needle aspiration biopsy is crucial in the investigation of a thyroid nodule. It provides highly accurate cytologic information about the nodule from which a definitive management plan can be formulated. The challenge remains in the management of nodules that fall under the "indeterminate" category. These may be subject to more surgical intervention than is required because histological examination is the only way in which a malignancy can be excluded. Surgery followed by radioactive iodine ablation is the mainstay of treatment for differentiated thyroid cancers, and the majority of patients can expect high cure rates.

TNM Classification of Thyroid Carcinoma

BACKGROUND

The understanding of biology of well-differentiated thyroid cancer has improved in the last two decades with the detailed understanding of prognostic factors and risk group stratification. The risk groups are crucial in the management of thyroid cancer and overall prognosis.

TNM STAGING SYSTEM

The TNM staging system has been used in all human cancers, and it adheres to the biology of tumors. The data in thyroid cancer comes from retrospective studies, as there are no prospective randomized trials. The most recent TNM staging system was revised and published (6th edition) in 2002. The major attributes of the staging system include: age as the most important prognostic factor, and age is included in the staging system, below and above the age of 45; T1 tumors are considered to be those below 2 cm; T3 tumors include minor extrathyroidal extension invading the strap muscles; T4 tumors includes T4a and T4b, T4a being operable tumors; all anaplastic cancers are T4, although operable anaplastic thyroid cancers are considered to be T4a.

CONCLUSION

These changes in the TNM system are consistent with our current philosophy in the overall management of thyroid cancer and adjuvant therapy. The N staging system includes N1a and N1b-N1a being level VI lymph nodes, while N1b includes level IV and superior mediastinal and contralateral neck nodes. The TNM staging system helps reporting our data and comparing results in different parts of the world. However, there is no level I evidence in thyroid cancer.

Treatment of thyroid cancer based on risk groups

The understanding of the prognostic factors and risk groups is crucial in the management of well differentiated thyroid cancer. The important prognostic factors are age, grade of tumor, extrathyroidal extension, size of tumor, and distant metastases. Based on these prognostic factors, patients can be divided into low-, intermediate-, and high-risk groups. The treatment decisions should be based on risk group analysis. Extent of thyroidectomy and adjuvant therapy can be based on the risk group analysis. The histopathologic studies are very important to distinguish well differentiated from the tall cell, insular, and poorly differentiated thyroid cancer.

Evaluation of the thyroid nodule

BACKGROUND

Thyroid nodules are common, yet treatment modalities range from observation to surgical resection. Because thyroid nodules are frequently found incidentally during routine physical examination or imaging performed for another reason, physicians from a diverse range of specialties encounter thyroid nodules. Clinical decision making depends on proper evaluation of the thyroid nodule.

METHODS

The current literature was reviewed and synthesized.

RESULTS

Current evidence allows the formulation of recommendations and a general algorithm for evaluating the incidental thyroid nodule.

CONCLUSIONS

Only a small percentage of thyroid nodules require surgical management. Diagnosis and treatment selection require a risk stratification by history, physical examination, and ancillary tests. Nodules causing airway compression or those at high risk for carcinoma should prompt evaluation for surgical treatment. In nodules larger than 1 cm, fine-needle aspiration biopsy is central to the evaluation as it is accurate, low risk, and cost effective. Subcentimeter nodules, often found incidentally on imaging obtained for another purpose, can usually be evaluated by ultrasonography. Other laboratory and imaging evaluations have specific and more limited roles. An algorithm for the evaluation of the thyroid nodule is presented.

Evaluation and management of incidentally discovered thyroid nodules

Thyroid nodules are present in 4-10% of the adult population. However, less than 1% of all cancers occur in the thyroid gland. Thyroid nodules are usually an incidental finding in a routine clinical or an ultrasound examination of the neck performed for some other reason. Differentiating a benign nodule, which may require no specific treatment, from a malignant nodule presents a diagnostic dilemma. An individualized approach to a patient with history, risk factors and fine needle cytology is warranted. Molecular markers and immunohistochemical studies done on thyroid nodule cytology may help in differentiating benign from malignant. This article presents a review of the literature for the diagnosis and management of the thyroid nodule.

Utilidad de la biopsia intraoperatoria en el tratamiento quirúrgico del nódulo tiroideo

OBJECTIVE

To present our experience of the use of frozen section (FS) in the operative management of thyroid nodules and determine the utility of this procedure when deciding the extent of thyroidectomy.

PATIENTS AND METHOD

We performed a prospective and comparative study. The FS of patients who underwent surgery for thyroid nodules between 1995 and 2002 were evaluated. The results were compared with those of fine-needle aspiration cytology (FNA) and definitive biopsy. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and diagnostic accuracy of both FNA and FS were calculated.

RESULTS

There were 469 thyroidectomies and 179 FS were performed. The results obtained for FNA and FS were, respectively: PPV: 100%/100%; NPV: 89%/90%; diagnostic accuracy: 89.5%/91%. When only "follicular hyperplasia" was included as the cytologic diagnosis, the PPV and NPV for FS were 100% and 86.7%, respectively.

CONCLUSION

The diagnostic accuracy of FNAC and FS is similar. In cases of follicular hyperplasia, the sensitivity of FS is too low to rule out malignancy.

MUC1 plays a role in tumor maintenance in aggressive thyroid carcinomas

BACKGROUND

We recently identified MUC1 as a target driving selection for 1q21 amplification and validated it as an independent marker of aggressive behavior in thyroid cancer (TC). The aims of this study were to determine whether TC cell lines retain MUC1 expression patterns that are seen in primary tumors, assess the role of MUC1 in tumor maintenance, and develop a virally delivered anti-MUC1 RNA interference (RNAi) that is effective in decreasing MUC1 expression in vitro.

METHODS

Fifteen TC cell lines were screened for MUC1 protein expression. Cell lines with varying MUC1 protein levels were treated with anti-MUC1 monoclonal antibody to assess cell viability. A recombinant retroviral short hairpin RNAi delivery system against MUC1 was developed. Efficacy and optimal dosing of short hairpin RNA against MUC1 was determined.

RESULTS

MUC1 expression patterns in TC cell lines were found to be similar to that seen in primary tumors. Treatment with anti-MUC1 antibody resulted in a significant decrease in cell viability in MUC1 over-expressing cell lines. MUC1-779 RNAi construct showed excellent infection efficiency and reproducible silencing.

CONCLUSION

These data offer functional evidence that implicates MUC1 over-expression as a key molecular event in the pathogenesis of aggressive TC. Retrovirally delivered anti-MUC1 RNAi is effective in silencing MUC1 and merits further investigation to establish therapeutic efficacy and safety in anticipation of potential clinical application.

Class distinction between follicular adenomas and follicular carcinomas of the thyroid gland on the basis of their signature expression

BACKGROUND

Nodules of the thyroid gland are observed frequently in patients who undergo ultrasound studies. The majority of these nodules are benign, corresponding to goiters or adenomas, and only a small fraction corresponds to carcinomas. Among thyroid tumors, the diagnosis of follicular adenocarcinomas by preoperative fine-needle aspiration biopsy is a major challenge, because it requires inspection of the entire capsule to differentiate it from adenoma. Consequently, large numbers of patients undergo unnecessary thyroidectomy.

METHODS

Using data from gene expression analysis, the authors applied Fisher linear discriminant analysis and searched for expression signatures of individual samples of adenomas and follicular carcinomas that could be used as molecular classifiers for the precise classification of malignant and nonmalignant lesions.

RESULTS

Fourteen trios of genes were described that fulfilled the criteria for the correct classification of 100% of samples. The robustness of these trios was verified by using leave-1-out cross-validation and bootstrap analyses. The results demonstrated that, by combining trios, better classifiers could be generated that correctly classified >92% of samples.

CONCLUSIONS

The strategy of classifiers based on individual signatures was a useful strategy for distinguishing between samples with very similar expression profiles.

Locally advanced thyroid cancer

PURPOSE OF REVIEW

The purpose of this review is to summarize existing literature with respect to locally advanced thyroid cancer and define the intricacies of preoperative evaluation, surgical management of involved sites and postoperative treatment.

RECENT FINDINGS

Locally invasive thyroid cancer is an uncommon disease process, which carries significant morbidity and mortality. Current treatment modalities include appropriate surgery, radioactive iodine treatment and external beam radiation therapy. Proper evaluation of the extent of disease, with complete gross tumor removal, is paramount in managing this difficult problem. Surgical treatment is still the mainstay for locally advanced thyroid cancer.

SUMMARY

Little progress has been made in advancing the treatment of locally advanced thyroid cancer. Patient identification, evaluation and proper surgical management with adjuvant therapy, still remain the most effective course of treatment. Aggressive surgical treatment including removal of all gross tumor and still preserving vital structures along with adjuvant therapy is likely to offer the best results. There is a very high incidence of locoregional and distant failure in this group of patients. The understanding and recognition of histopathological variations, such as poorly differentiated thyroid cancer is also important. New molecular markers are needed to help identify and predict aggressive tumor behavior.

Diagnostic Accuracy of Palpation-Guided and Image-Guided Fine-Needle Aspiration Biopsy of the Thyroid

We conducted a retrospective study to compare the sensitivity and specificity of traditional palpation-guided fine-needle aspiration biopsy (FNAB) performed by clinicians and pathologists with that of image-guided FNAB performed by radiologists for the evaluation of thyroid nodules. We reviewed the medical records of 89 patients who had undergone thyroid FNAB and subsequent surgical excision and pathology. Of this group, 58 patients had undergone palpation-guided FNAB performed by a clinician, 20 had undergone palpation-guided FNAB performed by a pathologist, and 11 had undergone image-guided FNAB performed by a radiologist. The sensitivity of the three techniques was 86, 100, and 100%, respectively, and the specificity was 78, 94, and 44%; there were no statistically significant differences in sensitivity or specificity among the three groups. Our data indicate that FNAB of the thyroid can be performed with equal reliability by clinicians, pathologists, and radiologists.

Expression profile of malignant and non-malignant diseases of the thyroid gland reveals altered expression of a common set of genes in goiter and papillary carcinomas

Using cDNA microarrays with 3800 cDNA fragments, we determined the expression profile of normal thyroid tissue, goiter, adenoma and papillary carcinoma (10 samples from each class). After background correction and statistical analysis, we identified a set of 160 genes as being differentially expressed in all pair-wise comparisons. Here we demonstrate that, at least on the basis of these differentially expressed genes, a positive correlation between goiter and papillary carcinomas could be observed. We identified a common set of genes whose expression is diminished in both goiter and papillary carcinomas as compared to normal thyroid tissue. Moreover, no genes with inverse correlation in samples from goiter and papillary carcinomas could be detected. Using Real-Time PCR and/or tissue microarrays, we confirmed the altered expression of some of the identified genes. Of notice, we demonstrate that the reduced mRNA levels of p27(kip1) observed in papillary carcinomas as compared to either goiter or normal thyroid tissues (P<0.001) is accompanied by an altered protein distribution within the cell. In papillary carcinomas, P27(KIP1) is preferentially cytoplasmic as opposed to goiter or normal thyroid tissue, where P27(KIP1) is preferentially located in the nucleus. The exploitation of the data presented here could contribute to the understanding of the molecular events related to thyroid diseases and gives support to the notion that common molecular events might be related to the frequent observation of areas of papillary carcinomas in the gland of patients with goiter.

Advances in the management of thyroid cancer

The incidence of thyroid cancer is rapidly increasing in the United States. A large number of incidentalomas are found during routine head and neck evaluations. The diagnostic workup still revolves around fine needle aspiration biopsy. Ultrasound guided fine needle aspiration biopsy is likely to yield the best results. Surgical resection offers the best treatment choice. Controversy continues in relation to total versus less than total thyroidectomy. The incidence of complications is inversely proportional to the extent of surgery and obviously related to the experience of the operating surgeon. The decision regarding the extent of thyroidectomy should be based on prognostic factors and risk groups. Prognostic factors are well defined, such as age, grade of the tumor, extrathyroidal extension, size, distant metastasis, and histology. Nodal metastasis has minimal implications. Based on prognostic factors, thyroid cancer can be divided into low, intermediate and high risk groups. In the high risk group and in selected intermediate risk patients, radioactive iodine dosimetry and ablation should be considered after total thyroidectomy. PET scanning and the use of recombinant TSH have been major advances in follow-up care for patients with thyroid cancer. Thyroglobulin appears to be a very good tumor marker for follow-up. No major breakthrough is noted in the management of anaplastic thyroid cancer, however, identification of RET mutation has been extremely helpful in evaluating the family members of the patient with medullary thyroid cancer with strong consideration given to total thyroidectomy.

Role of intraoperative frozen section in the management of thyroid nodules

BACKGROUND

The role of intraoperative frozen section in the management of thyroid nodules is controversial. Its potential benefit is to facilitate one-stage total thyroidectomy. Most literature on this topic originates from overseas tertiary referral centres with a high percentage of cancer cases and a fully resourced frozen section service. The aim of the present study was to review all patients undergoing frozen section at a typical general surgical department in New Zealand (North Shore Hospital, Auckland) to see how often frozen section altered surgical strategy.

METHODS

A retrospective review of all frozen sections between November 1999 and June 2003 was performed. Patient records, operation notes and pathology reports were reviewed.

RESULTS

Forty-seven sequential frozen sections were included in the study. Thirteen patients had thyroid carcinoma (five follicular, three Hurthle cell, and five papillary). In only one patient did the result of an intraoperative frozen section result in a total thyroidectomy being performed instead of a thyroid lobectomy. The reason for this was the rare condition of Riedel's thyroiditis. In no patients did frozen section detect a cancer that was not diagnosed on preoperative fine-needle aspirate biopsy.

CONCLUSION

The present review found little benefit in performing intraoperative frozen section in this setting. As a diagnostic test the cost of frozen section (NZ $200 for each frozen section) needs to be weighed against its low clinical benefit.

[Rational diagnosis and surgical treatment of solitary thyroid nodules]

Few subjects in endocrine surgery have generated as much controversy as the management of thyroid nodule. The controversial issues include evaluation of laboratory findings and imaging diagnostic procedures in the patient with solitary thyroid nodule. The major issue in relation to controversies is choice of optimal diagnostic workup.

Role of Fine-needle Aspiration Biopsy and Frozen Section in the Management of Papillary Thyroid Carcinoma Subtypes

Since fine-needle aspiration biopsy (FNAB) was introduced, the value of frozen section (FS) has been questioned. This study compares FNAB and FS sensitivities among the usual form of papillary thyroid cancer (uPTC) and variants of PTC such as tall cell (tcPTC), follicular (fPTC), and Hurthle cell (HcPTC). A total of 257 patients who underwent preoperative FNAB, intraoperative FS, and thyroidectomy for PTC were, randomly selected from a database of a university teaching hospital in Toronto. There were 218 females (84.8%) and 39 males (15.2%), from 19 to 89 years of age (mean of 44 years), having uPTC (n = 212), fPTC (n = 24), HcPTC (n = 14), and tcPTC (n = 7). Data were analyzed using chi2 test. Sensitivities were calculated by division of true positives and by the sum of true positives and false negatives. True positives had to reflect a conclusive diagnosis of cancer. The FNAB sensitivities were uPTC (39.2%), fPTC (25%), HcPTC (42.9%), tcPTC (85.7%), similar to FS sensitivities (p = 0.497) for uPTC (44.3%), fPTC (16.7%), HcPTC (42.9%), and tcPTC (71.4%). Use of FS following FNAB increased sensitivities for uPTC to 56.1%, fPTC to 29.2%, and tcPTC to 100%. In addition, FS did not increase FNAB sensitivity in HcPTC. Combination FNAB plus FS failed in 43.9% of uPTC, 70.8% of fPTC, and 57.1% of HcPTC. We concluded that FNAB and FS sensitivity vary with PTC subtype and are still necessary for selection and treatment. The recognition of morphologic subtypes of PTC from the FNAB could optimize the selection of patients for intraoperative FS, enhance the preoperative assessment of prognosis, facilitate the surgical planning, and simplify the preparation of postoperative adjuvant therapy.

Genome-wide profiling of papillary thyroid cancer identifies MUC1 as an independent prognostic marker

Clinicopathological variables used at present for prognostication and treatment selection for papillary thyroid carcinomas (PTCs) do not uniformly predict tumor behavior, necessitating identification of novel prognostic markers. Complicating the assessment is the long natural history of PTC and our rudimentary knowledge of its genetic composition. In this study we took advantage of differences in clinical behavior of two distinct variants of PTC, the aggressive tall-cell variant (TCV) and indolent conventional PTC (cPTC), to identify molecular prognosticators of outcome using complementary genome wide analyses. Comparative genome hybridization (CGH) and cDNA microarray (17,840 genes) analyses were used to detect changes in DNA copy number and gene expression in pathological cPTC and TCV. The findings from CGH and cDNA microarray analyses were correlated and validated by real-time PCR and immunohistochemical analyses on a series of 100 cases of cPTC and TCV. Genes identified by this approach were evaluated as prognostic markers in cPTC by immunohistochemistry on tissue arrays. CGH identified significant differences in the presence (76 versus 27%; P = 0.001) and type of DNA copy number aberrations in TCV compared with cPTC. Recurrent gains of 1p34-36, 1q21, 6p21-22, 9q34, 11q13, 17q25, 19, and 22 and losses of 2q21-31, 4, 5p14-q21, 6q11-22, 8q11-22, 9q11-32, and 13q21-31 were unique to TCV. Hierarchical clustering of gene expression profiles revealed significant overlap between TCV and cPTC, but further analysis identified 82 dysregulated genes differentially expressed among the PTC variants. Of these, MUC1 was of particular interest because amplification of 1q by CGH correlated with MUC1 amplification by real-time PCR analysis and protein overexpression by immunohistochemistry in TCV (P = 0.005). Multivariate analysis revealed a significant association between MUC1 overexpression and treatment outcome, independent of histopathological categorization (P = 0.03). Analysis of a validation series containing a matched group of aggressive and indolent cPTCs confirmed the association between MUC1 overexpression and survival (relative risk, 2.3; 95% confidence interval, 1.1-5.5; P = 0.03). Our data suggest that MUC1 dysregulation is associated with aggressive behavior of PTC and may serve as a prognostic marker and potential therapeutic target in this disease.

Implications of prognostic factors and risk groups in the management of differentiated thyroid cancer

OBJECTIVES/HYPOTHESIS

The outcome in differentiated thyroid cancer generally depends on the stage of the disease at the time of presentation; prognostic factors such as age, grade, size, extension, or distant metastasis; and risk groups (eg, low or high risk). The author has reviewed a large number of patients with differentiated thyroid cancer to analyze their hypothesis and to confirm that various risk groups have a major implication in relation to extent of the treatment and outcome. Differentiated thyroid cancers make up 90% of all thyroid tumors. The prognostic factors are well defined, such as age, size of the tumor, extrathyroidal extension, presence of distant metastasis, histological appearance, and grade of the tumor. The author has previously divided the risk groups into low-, intermediate-, and high-risk categories based on prognostic factors. The study describes the author's treatment approach related to the extent of thyroidectomy and adjuvant therapy based on various risk groups and the long-term survival.

STUDY DESIGN

Retrospective.

METHODS

In a retrospective review of 1038 patients with differentiated thyroid carcinoma, various prognostic factors were studied by univariate and multivariate analysis. The significant prognostic factors were studied in detail and, based on these prognostic factors, the patients were divided into low-, intermediate- and high-risk groups. The survival curves were plotted by Kaplan-Meier method.

RESULTS

The long-term survivals in low-, intermediate- and high-risk groups were 99%, 87%, and 57% respectively. Based on these risk groups, a decision tree was made regarding extent of thyroidectomy and adjuvant treatment. In the high-risk group and selected patients in the intermediate-risk group, aggressive surgery including removal of all gross disease and extrathyroidal extension with postoperative radioactive iodine ablation is recommended. In the low-risk group and selected patients in the intermediate-risk group, lobectomy appears to be satisfactory with excellent long-term outcome. The surgical treatment offers the best long-term results in low-risk patients, and the role of adjuvant treatment in this group is questionable.

CONCLUSION

The decisions in the management of well-differentiated thyroid cancer should be based on various prognostic factors and risk groups. The long-term survival in the low-risk group is excellent, and consideration should be given to conservative surgical resection depending on the extent of the disease. In the high-risk group and selected patients in the intermediate-risk group, total thyroidectomy with radioactive ablation is warranted. A consideration may be given to external-beam radiation therapy in selected high-risk patients. It is apparent, based on the author's clinical experience and critical retrospective analysis, that the author's hypothesis that risk groups are extremely important in the long-term outcome of patients with differentiated thyroid cancer is correct. Based on various risk groups, the author currently is able to guide the treatment policies for thyroid cancer.

Safety of Modified Radical Neck Dissection for Differentiated Thyroid Carcinoma

OBJECTIVES/HYPOTHESIS

The management of cervical metastases from differentiated thyroid carcinoma (DTC) remains controversial. Most surgeons perform a neck dissection (ND) for clinically apparent disease. The extent of nodal dissection varies from regional to comprehensive. Morbidity from ND in the setting of DTC remains high, particularly when performed in the setting of a thyroidectomy (TT). To determine complications from ND for DTC, we retrospectively reviewed our surgical experience of modified radical neck dissection for nodal metastases.

STUDY DESIGN

Retrospective chart review.

METHODS

Between 1997 and 2002, 39 consecutive patients (31 females and 8 males) underwent 44 comprehensive NDs of levels II-V for DTC. Central compartment dissection (CCD) (levels VI and VII) was also performed during 23 of these procedures. Twenty (45.5%) patients had prior treatment elsewhere. Preoperative pathology revealed papillary carcinoma in 22 patients (56.4%), tall cell variant in 11 (28.2%), and follicular variant in 6 (15.4%).

RESULTS

Ten patients (20%) underwent ND alone, whereas 6 (14%) underwent simultaneous ND and TT. Fifteen patients underwent simultaneous ND, TT, and CCD (30%). Temporary hypocalcemia occurred after 21% of NDs that were performed in the setting of either TT or CCD or both. There were no cases of permanent hypoparathyroidism. Transient regional lymph node (RLN) paresis occurred in two patients and was associated with a concomitant central compartment nodal dissection; there were no permanent RLN palsies. Transient spinal accessory nerve paresis developed after 27% of NDs performed. Two patients developed chyle leaks.

CONCLUSIONS

When ND is necessary for the treatment of thyroid malignancies, the procedure can be performed safely with acceptable morbidity.

Clinicopathologic significance of histologic vascular invasion in papillary and follicular thyroid carcinomas1 1No competing interests declared

BACKGROUND

The association of angioinvasion with tumor aggressiveness in follicular and papillary thyroid carcinoma remains unclear. This study addresses this problem focusing on clinicopathologic relevance of angioinvasion in the treatment of papillary thyroid carcinoma and follicular thyroid carcinoma.

METHODS

From a university hospital database, 358 patients with papillary thyroid carcinoma or follicular thyroid carcinoma were randomly selected. Their charts were retrospectively analyzed and divided into papillary thyroid carcinoma and follicular thyroid carcinoma groups. Each group was subdivided into angioinvasive and nonangioinvasive tumor subgroups. All data were analyzed using Student's t-test, Mann-Whitney rank sum test, chi-square test, and Fisher's exact test.

RESULTS

There were 289 women and 69 men, ages 18 to 89 years. Papillary thyroid carcinoma (86%) was more frequent than follicular thyroid carcinoma. Most patients had nonangioinvasive tumor (90.2%). After a mean followup of 43.6 months, there were no significant differences between papillary thyroid carcinoma subgroups for local recurrence (p = 0.69), persistent elevated serum thyroglobulin (p = 0.568), and distant metastasis rates (p = 0.422). No death related to the cancer was observed in both papillary thyroid carcinoma subgroups (p = 1), except for one death resulting from a concomitant nasopharyngeal cancer. The longterm prognosis was less favorable for angioinvasive papillary thyroid carcinoma based on AJCC (American Joint Committee on Cancer staging), AMES (age, distant metastasis, tumor extent, and size), and MACIS (distant metastasis, age, completeness of primary tumor resection, local invasion, and tumor size), but the angioinvasive papillary thyroid carcinoma were larger than nonangioinvasive papillary thyroid carcinomas. The short-term clinical outcomes in both follicular thyroid carcinoma, after a mean followup of 72.3 months, were comparable in terms of local recurrence (p = 0.34), persistent elevated serum thyroglobulin (p = 1), and distant metastasis (p = 0.597). There was no death related to cancer in both follicular thyroid carcinoma subgroups (p = 1). There were no significant differences between both follicular thyroid carcinoma subgroups for longterm prognosis.

CONCLUSIONS

Our results indicate that angioinvasion does not adversely influence short-term outcomes or longterm prognosis in follicular thyroid carcinoma and short-term outcomes in papillary thyroid carcinoma. Angioinvasion is a postoperative pathologic finding that does not justify an ominous prognosis or drastic therapeutic measures.

Differential expression of IGFBP-5 and two human ESTs in thyroid glands with goiter, adenoma and papillary or follicular carcinomas

Here, we describe the identification of three human genes with altered expression in thyroid diseases. One of them corresponds to insulin-like growth factor binding protein 5 (IGFBP5), which has already been described as over expressed in other cancers and, for the first time, is identified as overexpressed in thyroid tumors. The other genes, named 44 and 199, are ESTs with yet unknown function and were mapped on human chromosomes seven and four, respectively. We determined by RT-PCR the expression level of these genes in ten samples of disease-free thyroid, ten of goiter, nine of papillary carcinoma, ten of adenoma and seven of follicular carcinoma and the significance of observed differences was statistically determined. IGFBP-5 and gene 44 were significantly overexpressed in papillary carcinoma when compared to normal and goiter. Genes 44 and 199 were differentially expressed in follicular carcinoma and adenoma when compared to normal thyroid tissue.

Dipeptidyl peptidase IV expression in thyroid cytology: retrospective histologically confirmed study

Fine needle aspiration cytology (FNAC) of the thyroid gland is a well-established method. However, it has inherent limitations, especially in the diagnosis of follicular and oncocytic tumours and in distinguishing between nuclear atypia in colloid goitre with regressive changes and cystic papillary carcinoma. The aim of our study was to evaluate dipeptidyl peptidase IV (DPP IV) as a marker of malignancy in FNAC. We tested 254 thyroid specimens (intraoperative imprint smears) for DPP IV. The sensitivity was 71%, the specificity was 96%, and the diagnostic accuracy was 93%, respectively, with a threshold of 50% of positive cells. To the best of our knowledge it is the largest histologically confirmed study reported in the literature. We suggest the assessment of DPP IV as an adjunct diagnostic marker of malignancy in thyroid specimens suspicious of papillary carcinoma. However, the value of the marker in follicular lesions is very limited.

Evaluation of a thyroid nodule

Solitary thyroid nodules are common entities and the majority of these are benign. The main goal in evaluating these nodules is to identify the [figure: see text] nodules with malignant potentials. A multitude of diagnostic tests is available to the clinician. FNA biopsy is now considered the gold standard diagnostic test in the evaluation of a thyroid nodule. Ultrasound and nuclear scans are also useful tests, but are best used in conjunction with FNA. Clinical decisions are often based on the results of the FNA. A diagram of the clinical decision process based on FNA findings is presented in Fig. 1. Despite the clinical advantages that are provided by the FNA results, the clinician should not dismiss the importance of other clinical prognostic indicators to optimize timely treatment.