Clinical practice. The thyroid nodule

Nonshadowing echogenic foci in thyroid nodules: are certain appearances enough to avoid thyroid biopsy?

OBJECTIVES

The purpose of this study was to further classify nonshadowing echogenic foci and examine the association with malignancy.

METHODS

This study received Institutional Review Board approval and was Health Insurance Portability and Accountability Act compliant. A total of 371 consecutive thyroid nodules were evaluated in 189 patients (177 female and 12 male; mean age, 59 years; range, 21-92 years). Eighty-six nodules (23%) measured 5 mm or larger and contained nonshadowing echogenic foci with a mean nodule diameter of 16 mm (5-66 mm). Blinded review of these nodules 12 months later was performed. Echogenic foci were classified as follows: showing a comet tail artifact (type 1), linear and brightly echogenic (type 2), round and indeterminate (type 3), and microcalcifications (type 4). All available thyroid sonograms and pathologic data were then reviewed.

RESULTS

Nineteen nodules (22%) showed a classic comet tail artifact, with malignancy in 0 of 19. Six (32%) had negative pathologic results, and 9 (47%) had stable imaging follow-up (mean, 37 months). Twenty-nine nodules (34%) showed linear and brightly echogenic foci, with malignancy in 0 of 29. Fifteen (52%) had negative pathologic results, and 11 (38%) had stable imaging follow-up (mean, 34 months). Twenty-four nodules (28%) showed round and indeterminate echogenic foci, with 1 of 24 (4%) containing papillary carcinoma. Thirteen (54%) had negative pathologic results, and 8 (33%) had stable imaging follow-up (mean, 24 months). Fourteen nodules (16%) contained microcalcifications, with 4 of 14 (29%) containing papillary thyroid cancer. Nine (64%) had negative pathologic results, and 1 (7%) had stable imaging follow-up (63 months).

CONCLUSIONS

Nonshadowing brightly echogenic linear foci with or without a comet tail artifact may be a benign finding. Confirmatory studies are needed for this result to be applied clinically.

Fine needle aspiration of the thyroid: a contemporary experience of 3981 cases

BACKGROUND

Fine needle aspiration (FNA) is an essential tool for the management of thyroid nodules. Recently, several national organizations have recommended FNA of all thyroid nodules >1 cm. With the increase use of imaging in the practice of medicine over the last decade, the number of incidentally discovered thyroid nodules is rising. Therefore, we analyzed our experience to determine if these changes in practice led to alterations in the population of patients undergoing FNA at our institution.

MATERIALS AND METHODS

Data were collected from 981 consecutive patients who underwent thyroid FNA at our institution between 2002 and 2009. Patients were divided in two groups: the early time period 2002-2005 (group 1) and later time period 2006-2009 (group 2). Data from the two groups were analyzed with t-test and χ(2) tests (SPSS, Inc., Chicago, IL).

RESULTS

Comparing the groups, the number of FNAs performed in the later time period increased significantly by 250%. Patients in the later time period (group 2) were more likely to be female and were significantly older. With regard to FNA diagnoses, the number of benign FNAs increased, while the percentage of FNAs diagnosed as malignant and as follicular neoplasm decreased. There also appears to be an increase in the incidence of thyroiditis.

CONCLUSIONS

The use of thyroid FNA has markedly increased during this contemporary series. This rise in thyroid FNA appears to be due to biopsy of benign thyroid nodules. With time, more females and older patients have undergone FNA, possibly reflecting the increased use of imaging studies in this patient population.

Prognosis of thyroid function after hemithyroidectomy

Identify criteria and create a risk scoring system to predict hypothyroidism after hemithyroidectomy. We have retrospectively studied 216 cases of patients with goiter who had undergone hemithyroidectomy from January 2002 to December 2007 at Vilnius University Hospital Santariškių Klinikos. Patients were divided into two groups according to their thyroid function after hemithyroidectomy: 168 (77.8%) patients’ thyroid function was normal (group A), 48 (22.2%) patients had symptoms of hypothyroidism (group B). The relationship between groups and parameters such as patients’ sex, age, patient’s weight, preoperative serum thyroid-stimulating hormone (TSH) level, weight of the remnant gland, ratio of the remaining thyroid gland weight to patient’s weight was statistically analysed. The patients’ mean age was 41.6 ± 14.1 years in group A and 52.9 ± 13.9 years in group B (p=0.0002). The mean preoperative TSH level was 0.79 ± 0.5 mU/L in group A, compared with 1.42 ± 1.00 mU/L in group B (p= 0.005). The mean ratio of the remaining thyroid gland weight to patient’s weight was 0.102 ± 0.053 g/kg in group A and 0.063 ± 0.027 g/kg in group B (p=0.04). The groups did not establish a significant difference between patients’ sex, patient’s weight or weight of the remaining gland. Patient’s age, preoperative serum TSH level, ratio of the remaining thyroid gland weight to patient’s weight is the main factors of hypothyroidism after hemithyroidectomy. A risk scoring system was created to predict hypothyroidism after hemithyroidectomy before the operation.

Ultrasonographic characteristics predictive of nondiagnostic results for fine-needle aspiration biopsies of thyroid nodules

The objective of this study was to identify clinical and ultrasonographic (US) characteristics predictive of nondiagnostic results. An experienced radiologist performed an US-guided fine-needle aspiration biopsy (US-FNA) for 1493 thyroid nodules in 1419 patients. Cytological results were classified as nondiagnostic (<6 groups of cells containing more than 10 cells) or diagnostic. The clinical characteristics of patients and the US features of thyroid nodules were compared according to nondiagnostic or diagnostic results. Age and sex were not associated with nondiagnostic results. A cystic portion >50% and hypoechogenicity were independent factors for predicting nondiagnostic results in all nodules (odds ratios [OR] = 2.82 and 1.88, respectively). In 534 nodules with more than 50% of cystic portion, the size of more than 10 mm and in 813 solid nodules, the size of 5 mm or smaller increased the likelihood of nondiagnostic results (ORs = 3.61 and 1.88, respectively).

Role of ultrasound, clinical and scintigraphyc parameters to predict malignancy in thyroid nodule

Background

This study aimed to evaluate clinical, laboratory, ultrasound (US) and scintigraphyc parameters in thyroid nodule and to develop an auxiliary model for clinical application in the diagnosis of malignancy.

Methods

We assessed 143 patients who were surgically treated at a single center, 65% (93) benign vs. 35% (50) malignant lesions at final histology (1998-2008). The clinical, laboratory, scintigraphyc and US features were compared and a prediction model was designed after the multivariate analysis.

Results

There were no differences in gender, serum TSH and FT4 levels, thyroid auto-antibodies (TAb), thyroid dysfunction and scintigraphyc results (P = 0.33) between benign and malignant nodule groups. The sonographic study showed differences when the presence of suspected characteristics was found in the nodules of the malignant lesions group, such as: microcalcifications, central flow, border irregularity and hypoechogenicity. After the multivariate analysis the model obtained showed age (>39 years), border irregularity, microcalcifications and nodule size over 2 cm as predictive factors of malignancy, featuring 81.7% of accuracy.

Conclusions

This study confirmed a significant increase of risk for malignancy in patients of over 39 years and with suspicious features at US.

In thyroid fine-needle aspiration, use of bedside-prepared slides significantly increased diagnostic adequacy and specimen cellularity relative to solution-based samples

BACKGROUND

In the United States, the prevalence among adults of palpable thyroid nodules is 4%-7%, of which 5%-10% may represent thyroid carcinoma. Despite the success of fine-needle aspiration in reducing the need for thyroidectomy, aspirates are inadequate to render a diagnosis in 20% of cases. Minimizing nondiagnostic samples is an important goal in improving this technique. Our objective was to determine whether bedside-prepared slides improve diagnostic adequacy over standard solution-based samples. We further sought to determine the role of needle size.

METHODS

One hundred sixty-two patients were prospectively enrolled. For each, both bedside slides and standard cytology solutions were prepared; the order of preparation alternated from subject to subject. Needle size (21- or 25-gauge) also alternated from subject to subject. Slides were evaluated by pathologists blinded to needle size. The study took place in the endocrinology clinic at Boston Medical Center, the tertiary referral hospital of the Boston University School of Medicine. Key outcomes were diagnostic adequacy and specimen cellularity.

RESULTS

Compared to standard solution-based samples, bedside slides provided more cellular specimens (p < 0.01) and fewer nondiagnostic samples (p = 0.016). When standard solution-based samples were used as the sole method of preparation, 21-gauge needles provided improved diagnostic adequacy.

CONCLUSIONS

Bedside-prepared slides offer improved diagnostic adequacy and specimen cellularity over solution-based samples. The difference may be especially important when using smaller (25-gauge) needles to perform fine-needle aspiration. When solution-based samples are used, larger (21-gauge) needles provide more diagnostic specimens.

Thyroid nodules; interpretation and importance of fine-needle aspiration (FNA) for the clinician - practical considerations

Thyroid nodules are very common lesions. Despite that the great majority is benign, in a significant percentage of them there is an underlying malignancy. Malignant thyroid nodules should be managed surgically, while the more common benign thyroid nodules may be managed conservatively. A systemic and careful diagnostic evaluation is needed to recognize nodules (overtly malignant or with malignant potential), and to avoid unnecessary surgery in a large percentage of patients with benign disease. Fine-needle aspiration (FNA) has a central role in the diagnostic investigation of the patient with thyroid nodules. FNA is a safe, useful, and cost-effective procedure. To increase accuracy, FNA can be performed under ultrasonographic guidance (if needed). Its results may be particularly helpful in determining the indication for surgery. In contrast, the role of FNA in selecting the extent of surgery is limited today. This is due to the fact that during the last decade there is a clear trend toward radical surgical management of thyroid nodular disease (both benign and malignant) by total/near-total thyroidectomy.

Diagnostic value of elastosonographically determined strain index in the differential diagnosis of benign and malignant thyroid nodules

Elastosonography (ES) is a newly developed method that is used for the differential diagnosis of benign and malignant thyroid nodules. In different studies, ES scoring has been compared with histopathological findings, and sensitivity and specificity of the scoring were calculated. In this study, it determines the strain index (SI) as well as the ES to score thyroid nodules, and establishes the role for these parameters in the differential diagnosis of thyroid nodules using histopathological analysis as a reference standard. Real-time ES in transverse axis (TA) and longitudinal axis (LA) was performed in 391 nodules of 292 patients. ES scoring was made for all the nodules. SI in TA and LA was calculated for four times in each nodule and mean values were determined. The results were compared with final histopathological diagnoses. In histopathological examinations, 125 (31.97%) of 391 nodules were malignant and 266 (68.03%) were benign. Of these histopathologically benign nodules, 189 (%71.05) were also probably benign according to elastosonographic scoring (scores of 1, 2, or 3), while 77 (28.95%) were probably malignant (scores of 4 or 5). Among 125 histopathologically malignant nodules, 52 (41.60%) were probably benign and 73 (58.40%) were probably malignant according to elastosonographic scoring. There was a significant relation between scoring and histopathological findings (χ(2) = 36.513; P < 0.001). Accordingly, sensitivity and specificity of ES scoring were 58.4 and 71.0%, respectively. ROC analysis value obtained for strain ratios in LA (AUC: 75.5%; P < 0.001) had a higher significance compared to ROC analysis value obtained for strain ratios in TA (AUC: 66.0%). Thus, ROC analysis evaluation was applied only for SI in LA. The optimal SI cut-off value in LA for all the nodules was found to be 16.709 (sensitivity: 73.4%, specificity: 70.0%) (AUC: 75.4 ± 0.03%; 70.2-80.5%). SI cut-off value corresponding to 90% sensitivity in this axis was 4.516 (specificity: 35.7%). Sensitivity and specificity of SI values that were determined according to morphological features of nodules in gray-scale ultrasonography were higher. For hypoechoic nodules with microcalcifications and without a halo, SI cut-off value, sensitivity, and specificity were 17.020, 84.3, and 81.1%, respectively. Our study is the first clinical-wide series study that measured, used, and compared the ES scoring and SI cut-off values for the differential diagnosis of benign and malignant thyroid nodules. This study indicates that measurement of SI with ES as a noninvasive procedure may be used as an adjunctive method to the conventional methods for the differential diagnosis of thyroid nodules.

Complex thyroid nodules with nondiagnostic fine needle aspiration cytology: histopathologic outcomes and comparison of the cytologic variants (cystic vs. acellular)

Management of complex thyroid nodules (CTN) is a common dilemma due to their high prevalence and frequent nondiagnostic fine needle aspiration cytology (FNAC). In order to know the rate of malignancy, we reviewed our experience about histopathologic diagnosis of CTN with nondiagnostic FNAC, and we analyzed if cytological variants of nondiagnostic FNAC indicated different histopathologic outcomes. We conducted a review of 927 consecutive aspirations performed between 2003 and 2008. We selected patients without history of radiation, with echographic CTN, and nondiagnostic FNAC, who underwent surgery. We analyzed histopathologic results and compared patients with benign and malignant nodules, and searched for differences between patients with cystic changes in FNAC (C-FNAC), and patients with acellular or only bloody FNAC (A-FNAC). Thirty-six patients were included (mean age 45.7 ± 13 years; 30 females). Four patients had malignant nodules; all were papillary carcinomas. Patients with benign nodules had a similar profile to patients with malignant nodules. Patients with C-FNAC (n = 21) were younger (41.3 ± 12.6 vs. 51.8 ± 11.2 years; P < 0.02), had more lymphocytic thyroiditis (33.3 vs. 0%; P < 0.02), a slightly higher rate of carcinoma in the nodule (14.3 vs. 6.6%; P: ns), and also of papillary microcarcinoma outside the nodule (9.6 vs. 0%; P: ns) than patients with A-FNAC. In conclusion, we report an 11.1% malignancy rate in CTN with nondiagnostic FNAC. Nodules with C-FNAC variant had a slightly higher rate of malignancy than A-FNAC, which may be in relation with younger age and higher prevalence of lymphocytic thyroiditis in this group of patients.

An ultrasound model to discriminate the risk of thyroid carcinoma

RATIONALE AND OBJECTIVES

Thyroid nodules are common on ultrasonographic examination and are mostly benign. Ultrasound characteristics may help discriminate thyroid carcinoma (TC) from benign nodules. The aims of this study were to identify ultrasonographic characteristics associated with TC and to validate a previously proposed model based on the presence of three ultrasonographic characteristics.

MATERIALS AND METHODS

From a protocolized prospective registry of 1108 fine needle aspiration biopsies performed during a 16-month period at an ambulatory center, the ultrasonographic characteristics of TC and non-TC biopsies were compared. Adjusted odds ratios (ORs) and likelihood ratios for TC were estimated for eight combinations of three previously identified characteristics (microcalcifications, hypoechogenicity, and irregular borders).

RESULTS

Microcalcifications (OR, 6.6; 95% confidence interval [CI], 4.4-9.9), hypoechogenicity (OR, 4.7; 95% CI, 2.8-8.0), and irregular borders (OR, 4.3; 95% CI, 2.8-6.5) were independently associated with TC. When added to a logistic regression model, the three ultrasonographic characteristics remained statistically significant. In the absence of these three features, the likelihood ratio for TC was 0.1 (95% CI, 0.0-0.2), while in their simultaneous presence, the likelihood ratio was 11 (95% CI, 6.6-19.0).

CONCLUSIONS

The absence or simultaneous presence of three simple ultrasonographic characteristics generates a large change of pretest probability of TC and could avoid unnecessary fine needle aspiration biopsy.

Presentation of clinically solitary thyroid nodules in surgical patients

BACKGROUND

Thyroid nodules occupy a unique position in relation to clinical diagnosis since most patients with a thyroid nodule do not present with overt symptoms. There are, however, no good published data demonstrating the way in which clinically solitary thyroid nodules come to medical attention, with most of the literature being anecdotal. This study aims to evaluate the mode of presentation of solitary thyroid nodules, and to assess whether the presence of a malignancy influences that presentation.

METHODS

In this retrospective cohort study, data were obtained from the University of Sydney Endocrine Surgery Database and through a review of the patient records. The study cohort comprised 419 consecutive patients who presented with a clinically solitary thyroid nodule and who subsequently underwent surgery. Patient files lacking data on mode of presentation and patients in whom thyroid nodules were incidentally discovered during parathyroid surgery were excluded, leaving a total of 299 patients. Data were analyzed using a computer-based statistical software package. Continuous variables were compared using Student's t-test. Categorical variables were analyzed using Fishers exact test. Statistical significance was set at p < 0.05.

RESULTS

Solitary thyroid nodules are most commonly detected by the patients themselves (40%), followed by the incidental discovery of nodules on imaging studies performed for unrelated reasons (30%), and lastly due to third-party diagnosis by family, friends, acquaintances, or medical practitioners (30%). Nodules detected by medical practitioners were statistically more likely to be malignant (p = 0.02). No other differences between the clinical presentation of benign and malignant nodules were found.

CONCLUSIONS

Patients themselves are the ones who most commonly first become aware of the thyroid nodules that are eventually seen by thyroid surgeons. Incidental discovery on image studies is also important. Thyroid nodules detected by medical practitioners should be dealt with most urgently because they are most likely to be malignant.

Endocrine Society of India management guidelines for patients with thyroid nodules: A position statement

Thyroid nodules are common. Thyroid cancer is rarer. No guidelines exist for management of thyroid nodules in the Indian context and these recommendations are intended for this purpose. The consensus committee reviewed important articles, including previously published consensus statements. Management points were scored according to the level of evidence. These guidelines cover the clinical evaluation and include the interpretation of imaging and fine needle aspiration cytology of thyroid nodules. The guidelines also cover the management of special situations like thyroid incidentalomas, cystic thyroid lesion and nodules detected during pregnancy. The consensus guidelines represent a summary of current medical evidence for thyroid nodule management and the committee has attempted to optimize the guidelines for the clinical practice setting in India.

The utility of BRAF testing in the management of papillary thyroid cancer

This review summarizes the current literature surrounding BRAF and its significance in thyroid cancer.

Over the last decade, investigators have developed a clearer understanding of the genetic alterations underlying thyroid carcinogenesis. A number of biomarkers involved in the pathogenesis of differentiated thyroid cancer have undergone intensive study, not only for their role in tumorigenesis, but also for their potential utility as diagnostic and prognostic indicators and therapeutic targets. This review summarizes the current literature surrounding BRAF and its significance in thyroid cancer. Further, we discuss how molecular analysis can be integrated into management algorithms for thyroid nodules and papillary thyroid cancer. We also review what is known, to date, about the association of BRAF and papillary microcarcinoma as well as using targeted therapies for BRAF as adjuvant treatment for metastatic papillary thyroid cancer.

[Benign thyroid nodule or thyroid cancer?]

Thyroid nodular disease is highly frequent and affects 20-23% of the adult population in Germany. Differential diagnosis of thyroid nodules is directed at exclusion of thyroid autonomy and thyroid cancer. In addition, large nodules/nodular goiters may cause oesophageal and/or tracheal compression. Besides the patient's history and clinical examination, laboratory investigations (TSH-level, calcitonin screening), functional (scintiscan) and morphological imaging (ultrasound, in rare cases also CT without contrast media and MRI), as well as fine needle aspiration biopsy are useful tools in the differential diagnosis. In the past years, major advances have been made in the understanding of the molecular pathogenesis of thyroid tumors. This has led to the possibility of a molecular classification of thyroid tumors and may have prognostic as well as therapeutic impact.

Fine-needle aspiration biopsies for gene expression ratio-based diagnostic and prognostic tests in malignant pleural mesothelioma

PURPOSE

Malignant pleural mesothelioma (MPM) is an aggressive disease associated with median survival between 9 and 12 months. The correct diagnosis of MPM is sometimes challenging and usually requires solid tissue biopsies rather than fine-needle aspiration biopsies (FNA). We postulated that the accuracy of FNA-based diagnosis might be improved by the addition of molecular tests using a gene expression ratio-based algorithm and that prognostic tests could be similarly performed.

EXPERIMENTAL DESIGN

Two MPM and 2 lung cancer cell lines were used to establish the minimal quantity of RNA required to perform the gene ratio test. On the basis of these results, 276 ex vivo FNA biopsies from 63 MPM patients and 250 ex vivo FNA samples from 92 lung cancer patients were analyzed using previously described diagnostic and prognostic tests based on gene expression ratios.

RESULTS

We found that the sensitivity of the diagnostic test for MPM was 100% [95% confidence interval (CI): 95%-100%] and the specificity in primary lung adenocarcinoma was 90% (95% CI: 81%-95%). The FNA-based prognostic classification was concordant among 76% (95% CI: 65%-87%) of patients with the risk assignment in a subset of the matched surgical specimens previously analyzed by the prognostic test.

CONCLUSIONS

Sufficient RNA can be extracted from most FNA biopsies to perform gene expression molecular tests. In particular, we show that the gene expression ratio algorithms performed well when applied to diagnosis and prognosis in MPM. This study provides support for the development of additional RNA molecular tests that may enhance the utility of FNA in the management of other solid cancers.

Involvement of CYP1A1, GST, 72TP53 polymorphisms in the pathogenesis of thyroid nodules

Specific genotypes appear to be related to the development of thyroid disease. We examined whether polymorphisms of the genes CYP1A1, GSTM1, GSTT1, and TP53 at codon 72 are associated with increased risk for thyroid nodules. Blood samples were obtained from 122 thyroid patients with nodules and from 134 healthy control individuals from Goiânia city, GO, Brazil. We found no significant association of CYP1A1m1 and CYP1A1m2 genotypes with thyroid diseases (P > 0.05). The null genotypes of GSTM1 and GSTT1 genes were predominant in patients with nodules, indicating that individuals that possess these genotypes have a predisposition for thyroid disease. The genotype p53Arg Arg was associated with a low risk for thyroid cancer (OR = 0.15; P < 0.0001), indicating that the arginine allele in homozygosis could have a protective effect against carcinogenesis. On the other hand, the p53ArgPro genotype was significantly associated with malignant neoplastic nodules (OR = 3.65; P = 0.001). Interindividual variation in susceptibility to thyroid diseases could provide new perspectives for early diagnosis, prognosis and treatment, indicating which patients with thyroid nodules will benefit from treatment, depending on specific polymorphic profiles.

Percutaneous laser ablation of cold benign thyroid nodules: a 3-year follow-up study in 122 patients

BACKGROUND

Percutaneous laser ablation (PLA) is a proposed therapeutic procedure for the management of benign thyroid nodules. However, long-term results are unknown. The aim of this study was to evaluate retrospectively the safety and effects of PLA treatment in patients with benign nonfunctioning thyroid nodules in a 3-year follow-up.

METHODS

One hundred twenty-two patients (95 women and 27 men; age 52.2 ± 12.3 years) with benign cold thyroid solitary nodules or a dominant nodule within a normo-functioning multinodular goiter (volume range: 2.6-86.4 mL) underwent thermal Nd:YAG laser ablation of thyroid nodular tissue by 1-4 optical fibers positioned into the tissue by 21-gauge needles under ultrasound real-time assistance. The setting was an interventional suite and outpatient endocrine clinics in a community hospital in Italy. Nodule volume, ablation volume, side effects, serum thyroid-stimulating hormone (TSH), free triiodothyronine, free thyroxine (fT4), thyroglobulin (Tg), anti-Tg, anti-thyroperoxidase antibodies, symptoms, and cosmetic signs were recorded.

RESULTS

Data are mean ± standard deviation. Energy delivered was 8522  ± 5365 J with an output power of 3.1 ± 0.5 W. Three years after PLA, nodule volume decreased from 23.1 ± 21.3 to 12.5 ± 18.8 mL (-47.8%  ± 33.1% of initial volume, p ≤ 0.001). At day 1, TSH and fT4 values significantly changed (time 0 vs. day 1: TSH = 1.16  ± 1.06 vs. 0.62 ± 0.81 μU/mL, p ≤ 0.001; fT4 = 11.68 ± 1.88 vs. 13.20 ± 3.32 pg/mL, p ≤ 0.01) and normalized within 1 month. No change in free triiodothyronine, thyroperoxidase antibodies, and Tg antibodies values was observed. Symptoms improved in 89 patients (73.0%), were unchanged in 28 (22.9%), and worsened in 5 (4.1%). Cosmetic signs improved in 87 patients (71.3%), were unchanged in 29 (23.8%), and worsened in 6 (4.9%). In 11 patients (9%), nodules regrew above baseline. Two patients (1.6%) experienced delayed (12-24 hours) laryngeal dysfunction with vocal cord motility recovery after 6-10 weeks. Two patients (1.6%) became hypothyroid and two patients (1.6%) hyperthyroid after PLA.

CONCLUSIONS

After 3 years, the PLA technique achieved shrinkage of about 50% of the initial volume in a wide size range of benign cold thyroid nodules, with an improvement in local symptoms and signs. Side effects and failures were few although not negligible. PLA may be a new option for the management of benign cold thyroid nodules. Long-term controlled studies are required to establish the eligibility of patients for routine PLA.

Real-time elastography for the differentiation of benign and malignant thyroid nodules: a meta-analysis

BACKGROUND

Work-up of thyroid nodules remains challenging. Fine-needle aspiration (FNA) has been shown to be the most cost-effective way to select patients for surgery with sensitivities of 54%–90% and specificities of 60%–96% for the detection of malignant lesions. Ultrasound-based real-time elastography (RTE) enables the determination of tissue elasticity and has shown promising results for the differentiation of thyroid nodules. A meta-analysis was performed to assess the overall performance of RTE for the differentiation of thyroid nodules.

METHODS

Literature databases were searched. The inclusion criteria for studies were the use of FNA cytology histopathology of surgical specimens as the diagnostic reference standard and assessment of sensitivity and specificity of RTE. The meta-analysis was performed using an inverse variance method and the Der Simonian and Laird Random effect estimator in case of established heterogeneity.

RESULTS

Eight studies that included a total of 639 thyroid nodules were analyzed. The overall mean sensitivity and specificity for the diagnosis of malignant thyroid nodules by RTE of the eight studies was 92% confidence interval 88–96 and 90% confidence interval 85–95, respectively. A significant heterogeneity was found for specificity of the different studies.

CONCLUSIONS

RTE has a high sensitivity and specificity in the evaluation of thyroid nodules. This technique might be useful in conjunction or even instead of FNA to select patients with thyroid nodules for surgery.

Proteomic study of thyroid tumors reveals frequent up-regulation of the Ca2+ -binding protein S100A6 in papillary thyroid carcinoma

BACKGROUND

The accurate diagnosis of thyroid tumors is challenging. Proteomics has emerged as a promising approach for the discovery of molecular diagnostic markers as a potential complement to routine diagnostics.

METHODS

Protein fractions from 29 frozen thyroid tumor tissue samples (10 papillary carcinomas, 9 follicular carcinomas, and 10 follicular adenomas) as well as from normal thyroid tissue were analyzed by surface enhanced laser desorption/ionization time-of-flight mass spectrometry followed by validation by Western blotting and immunohistochemistry.

RESULTS

A Ca2+ binding protein belonging to the S100 family, S100A6, was differentially expressed between papillary and follicular thyroid tumors. Moreover, two posttranslationally modified forms of S100A6 were observed and verified by liquid chromatography-coupled tandem mass spectrometry. Validation by Western blotting displayed a significantly higher expression of S100A6 in papillary thyroid carcinoma (PTC) in comparison with the other tumor groups or normal tissue (p < 0.05). Immunohistochemical analysis on 98 tumors showed that PTC cases had a significantly stronger cytosolic staining and a larger proportion of stained nuclei than follicular tumors. BRAF gene mutation was not significantly associated with S100A6 protein levels.

CONCLUSION

This study supports a role of S100A6 in thyroid tumorigenesis and as a potential aid in the discrimination between follicular thyroid tumors and PTC.

Role of ultrasonography in thyroid disease

Ultrasonography (US) is the single-most valuable imaging modality in the evaluation of the thyroid gland. This review discusses the US appearances of thyroid nodules, emphasizing sonographic features associated with potentially malignant or, at the other end of the spectrum, likely benign nodules. Diffuse thyroid abnormalities have also been reviewed. The technique of ultrasound-guided fine-needle aspiration biopsy and the emerging role of elastography in characterizing thyroid nodules have also been addressed.

Fine-needle aspiration in the work-up of thyroid nodules

Fine-needle aspiration (FNA) is the crucial diagnostic test used for the evaluation of patients with a thyroid nodule. The result of an FNA determines if a patient can be followed with repeated examinations or referred for surgery. The value of FNA can be enhanced by attention to technical details. Communication between operator and pathologist is essential. A pathologist's interpretation is aided if essential clinical information is provided on a requisition form. Although reporting terminology has been varied and confusing in the past, a proposal for a uniform reporting system provides 6 clearly defined and clinically relevant reporting categories and promises to standardize the reporting of thyroid FNA results.

Surgeon-performed ultrasound in patients referred for thyroid disease improves patient care by minimizing performance of unnecessary procedures and optimizing surgical treatment

BACKGROUND

Ultrasonography has become an indispensable tool in the evaluation of thyroid nodular disease, and most patients will have had a thyroid ultrasound prior to initial surgical evaluation. This study examines the added benefit of office-based, surgeon-performed ultrasonography in patients referred for thyroid disease.

METHODS

All patients referred to a single endocrine surgeon for evaluation of thyroid disease over a 2-year period were reviewed. Outside ultrasonographic findings were compared to the surgeon-performed ultrasound that was used to formulate treatment decisions.

RESULTS

Of 286 consecutive patients referred for surgical evaluation of thyroid disease, 261 had an outside ultrasound available for comparison. There were 239 women and 47 men. Mean age was 54.7 +/- 16.6. In 46 patients (17.6%), differences between the two ultrasounds were significant enough to alter treatment plans. For 18 patients no distinct nodule was identified and biopsy was avoided. Nine of these patients had ultrasound characteristics of Hashimoto's disease. In five patients the nodule was significantly smaller than reported and biopsy was not warranted. Twelve patients had nonpalpable, enlarged lymph nodes not previously identified; these were biopsied. Three were positive for metastatic thyroid cancer, which prompted the addition of neck dissection to the operative procedure. In 8 of 132 patients undergoing thyroidectomy, the surgical procedure was significantly altered by the ultrasound findings.

CONCLUSIONS

This study demonstrates a clear advantage for patients who undergo a surgeon-performed ultrasound. For many, unnecessary procedures were prevented. For others, substantial modifications to the extent of surgery were made when new ultrasonographic findings were identified during the preoperative investigation.

Malignancy risk for fine-needle aspiration of thyroid lesions according to the Bethesda System for Reporting Thyroid Cytopathology

Fine-needle aspiration (FNA) is an important test for triaging patients with thyroid nodules. The 2007 National Cancer Institute Thyroid Fine-Needle Aspiration State-of-the-Science Conference helped instigate the recent publication of The Bethesda System for Reporting Thyroid Cytopathology. We reviewed 3,080 thyroid FNA samples and recorded interpretations according to the proposed standardized 6-tier nomenclature, and pursued follow-up cytology and histology. Of the 3,080 FNAs, 18.6% were nondiagnostic, 59.0% were benign, 3.4% were atypical follicular lesion of undetermined significance (AFLUS), 9.7% were "suspicious" for follicular neoplasm (SFN), 2.3% were suspicious for malignancy (SM), and 7.0% were malignant. Of 574 cases originally interpreted as nondiagnostic, 47.9% remained nondiagnostic. In 892 cases, there was follow-up histology. Rates of malignancy were as follows: nondiagnostic, 8.9%; benign, 1.1%; AFLUS, 17% (9/53); SFN, 25.4%; SM, 70% (39/56), and malignant, 98.1%. Thus, classification of thyroid FNA samples at the University of Virginia Health System, Charlottesville, according to The Bethesda System yields similar results for risk of malignancy as reported by others. Universal application of the new standardized nomenclature may improve interlaboratory agreement and lead to more consistent management approaches.

BRAFV600E mutation analysis in fine-needle aspiration cytology specimens for evaluation of thyroid nodule: a large series in a BRAFV600E-prevalent population

BACKGROUND

The BRAFV600E mutation is highly specific to papillary thyroid carcinoma. A test for this mutation may increase the diagnostic accuracy of fine-needle aspiration cytology (FNAC), especially in a BRAFV600E mutation-prevalent population.

METHODS

This prospective study enrolled 1074 patients with thyroid nodules who underwent both FNAC and BRAFV600E mutation analysis by dual-priming oligonucleotide (DPO)-based multiplex PCR in FNA specimens.

RESULTS

The ancillary test for BRAFV600E significantly improved the sensitivity of FNA procedure, from 67.5% with FNAC alone to 89.6% with FNAC and the DPO-based multiplex PCR analysis combined. Diagnostic accuracy increased from 90.9 to 96.6%. Nine cases of papillary thyroid carcinoma were detected only by BRAFV600E mutation analysis. Unexpectedly, the preoperative DPO-based multiplex PCR produced five false-positive results, which surgery showed to represent benign nodules.

CONCLUSIONS

Molecular testing for the BRAFV600E mutation in FNA thyroid nodule specimens increases diagnostic value when applied in a BRAFV600E mutation-prevalent population. However, when using this potentially powerful technique, we must consider both its strengths and its weaknesses.

Benefit of measuring basal serum calcitonin to detect medullary thyroid carcinoma in a Danish population with a high prevalence of thyroid nodules

BACKGROUND

Routine measurement of serum calcitonin to detect medullary thyroid carcinoma (MTC) continues to be fiercely debated, although less attention has been paid to the positive predictive value (PPV) of this method.

METHODS

We collected data from 959 patients with nontoxic nodular goiter; thyroidectomy was performed in 307 of these patients.

RESULTS

Thirty-nine patients had elevated serum calcitonin; 6 of these patients had MTC detected by the initial diagnostic setup. No additional patient in the cohort was registered in the Danish Thyroid Cancer Database, reflecting that all patients with MTC were classified correctly initially. The sensitivity of serum calcitonin for detection of MTC was 100%, the specificity was 95.3%, the positive predictive value was 15.4%, and the negative predictive value was 100%.

CONCLUSION

Serum calcitonin has high sensitivity and specificity for detection of MTC. The low PPV might lead to unnecessary thyroid surgery. Thus, the result of serum calcitonin measurement should always be interpreted in the context of other clinical variables.

The use of endobronchial ultrasonography with transbronchial needle aspiration to sample a solitary substernal thyroid nodule

Solitary thyroid nodules (STNs) are frequently encountered in clinical practice. When sampling of an STN is deemed necessary, ultrasound-guided fine needle aspiration biopsy (US-FNAB) is the procedure of choice. In substernal STNs, US-FNAB is not feasible, and the patients are usually offered either more invasive diagnostic testing (mediastinoscopy or surgical excision) or follow-up imaging studies based on the clinical suspicion of malignancy. We report a case in which a substernal STN was sampled using endobronchial ultrasonography with transbronchial fine needle aspiration (EBUS-TBNA). Our patient is a 74-year-old woman who was admitted with an asthma exacerbation. She underwent a chest CT scan with intravenous contrast (CTA) to rule out pulmonary embolism (PE). The CTA was negative for PE but showed a substernal STN that was successfully sampled by EBUS-TBNA without complications. The cytology was consistent with a colloid adenoma. EBUS-TBNA can sample substernal STNs that are not amenable to US-FNAB.

Calcitonin screening and pentagastrin testing: predictive value for the diagnosis of medullary carcinoma in nodular thyroid disease

CONTEXT

Serum calcitonin (hCT) measurement may be useful for detecting medullary thyroid carcinoma (MTC), but the routine use of hCT after pentagastrin stimulation to screen patients with nodular thyroid disease remains controversial.

PATIENTS

A total of 1007 patients (567 females and 440 males) with nodular thyroid disease and a mean age of 55+/-14 (mean+/-S.D.) years were included in the study. All patients did not have impaired renal function, bacterial infection, alcohol and drug abuse, pseudohypoparathyroidism, or proton-pump inhibitor therapy. Individuals referred with known elevation of hCT, Graves' disease, or autoimmune thyroid disease were not considered or included in this investigation.

METHODS

Serum hCT levels were determined under basal conditions, and when basal values were >or=10 and <100 pg/ml, testing was repeated after pentagastrin stimulation. Patients with basal or stimulated levels >100 pg/ml were referred for surgery.

RESULTS

hCT levels >10 pg/ml were increased in 17 patients (1.7%). One patient had a basal hCT level of 4400 pg/ml with a histological confirmation of a MTC. In this patient, pentagastrin test was not performed. Sixteen patients with basal hCT between 10 and 100 pg/ml underwent pentagastrin-stimulated hCT measurement. Of 16 patients, 4 had stimulated hCT>100 pg/ml. Of 17 patients with hCT>10 pg/ml, 2 had MTC, and of 17 patients, 3 had C-cell hyperplasia. In total, two patients (0.20%) had a histologically verified MTC.

CONCLUSIONS

Basal hCT measurement together with pentagastrin-stimulated hCT measurement in cases of basal hCT>10 pg/ml detects MTC in 0.20% of patients with nodular thyroid disease. Whether this high incidence of MTC has major implications or not has to be discussed, but it should be considered as a useful and recommended tool for early detection of MTC and to save patients' life.

Ultrasound-guided fine-needle aspiration of thyroid nodules: stratification of malignancy risk using follicular proliferation grading, clinical and ultrasonographic features

OBJECTIVE

To evaluate the diagnostic value of fine-needle aspiration (FNA) cytology and the additive contribution brought by clinical and ultrasound (US) features.

METHOD

Cytological and histological diagnoses were compared in a series of 924 patients who underwent US-guided FNA before surgery. We additionally developed a grading system for follicular proliferation (FP) FNA diagnosis, and investigated its impact on the malignancy risk as well as the additive contribution of clinical and US features by means of decision tree analysis.

RESULTS

Excluding FP cases (n=395), our data demonstrated that strictly benign or malignant FNA diagnoses exhibit great concordance with benign or malignant histological diagnoses (97.8% accuracy). Our grading system that was applied to the 395 FP cases revealed that grades 1, 2 and 3 were associated with a 7.7, 17.7 and 45.7% incidence of malignancy respectively. Decision tree analysis resulted in a classification model which involved FP grade, patient's age, serum thyroglobulin level, nodule size and nodule uniqueness. This model identified a subgroup of patients with grade 1 FP nodules who were older than 50 years, and who had a higher risk of malignancy (17.9%). In addition, high serum thyroglobulin levels were associated with a very high malignancy risk (75.0%) for patients with grade 3 FP nodules. Finally, among grade 2 FP patients, unique and large nodules were associated with a high malignancy risk of 36.1%.

CONCLUSIONS

The integration of FP grade, clinical and US features allows the stratification of patients with FP cytology according to their risk of malignancy.

The diagnostic accuracy of the immunocytochemical markers in the pre-operative evaluation of follicular thyroid lesions

Aim of the study was to consider the diagnostic accuracy of galectine-3 (GAL3) in the pre-operative cytological evaluation of follicular lesions.

MATERIALS AND METHODS

We retrospectively evaluated 100 patients suffering from thyroid nodular disease submitted to thyroidectomy from 2006 to 2007 in our Institution. Before surgery all patients underwent fine needle aspiration biopsy. The immunocytochemical analysis was performed on fine needle aspiration specimens using species-specific monoclonal antibodies and a biotin-free detection system. Based on preoperative cytological reports, 40 patients had pre-operative malignant results, and 60 patients (46 females and 14 males) showed follicular lesions. The sensitivity, specificity, positive and negative predictive values, and diagnostic accuracy of GAL3 was evaluated.

STATISTICAL ANALYSIS

Chi-square test was used to compare frequencies of GAL3 expression between the different hystopathological groups.

RESULTS

GAL3 proved to have 55% sensitivity, 100% specificity, 70% negative predictive value, and 78% diagnostic accuracy. The GAL3 expression in neoplastic and benign lesions was significantly different (GAL3+ in 16 out of 29 neoplastic lesions, GAL3+ 0 out of 31 benign lesions, p<0.01). Even comparing the GAL3 positivity between the follicular adenomas (0 GAL3+ out of 20) and the group of follicular carcinomas (5 GAL3+ out of 6), we found a statistically significant difference (p<0.01).

CONCLUSIONS

Based on the data from our experience, the patients with a cytological diagnosis of GAL3 positive follicular neoformation should be referred for surgery without any further immunocytological testing.

Towards high performance cell segmentation in multispectral fine needle aspiration cytology of thyroid lesions

Thyroid nodule is a common cancer of the thyroid gland that affects up to 20% of the world population and approximately 50% of 60-year-old persons. Early detection and screening of the disease, especially analysis by fine needle aspiration cytology (FNAC), has led to improved diagnosis and management of the disease. Simultaneously, advances in imaging technology has enabled the rapid digitization of large volumes of FNAC specimen leading to increased interest in computer assisted diagnosis (CAD). This has led to development of a variety of algorithms for automated analysis of FNAC images, but due to the large scale memory and computing resource requirements, has had limited success in clinical use. In this paper, we present our experiences with two parallel versions of a code used for texture-based segmentation of thyroid FNAC images, a critical first step in realizing a fully automated CAD solution. An MPI version of the code is developed to exploit distributed memory compute resources such as PC clusters. An OpenMP version is developed for the currently emerging multi-core CPU architectures, which allow for parallel execution on every desktop system. Experiments are performed with image sizes ranging from 1024 x 1024 pixels up to 12288 x 12288 pixels with 21 spectral channels. Both versions are evaluated for performance and scalability.

Multispectral microscopy and cell segmentation for analysis of thyroid fine needle aspiration cytology smears

This paper discusses the needs for automated tools to aid in the diagnosis of thyroid nodules based on analysis of fine needle aspiration cytology smears. While conventional practices rely on the analysis of grey scale or RGB color images, we present a multispectral microscopy system that uses thirty-one spectral bands for analysis. Discussed are methods and results for system calibration and cell delineation.

Are endogenously lower serum thyroid hormones new predictors for thyroid malignancy in addition to higher serum thyrotropin?

It is well known that TSH plays a major role in the secretion of thyroid hormones, maintenance of thyroid specific gene expression, and gland growth. In this study, we aimed to evaluate association between tests of thyroid functions (fT3, fT4, TSH) and differentiated thyroid carcinoma. 441 patients operated for nodular goiter between 2005 and 2008 were analyzed. Thyroid functions were studied in the period of 1-30 days prior to surgery. In postoperative histopathological examination, differentiated thyroid carcinoma and benign thyroid disease were detected in 166 (37.6%) and 275 (62.4%) patients, respectively. Patients with thyroid malignancy had significantly lower serum fT3 (P = 0.001), lower fT4 (P = 0.022), and higher TSH levels (P < 0.001) compared to patients with benign disease, although all analytes were within the normal range. We subdivided by quartile serum fT3, fT4, and TSH in normal limits into three groups. The odds ratio (ORs) for the risk of thyroid cancer with a serum TSH between 0.63 and 1.67 μIU/ml and 1.68-4.00 μIU/ml, compared with a serum TSH between 0.40 and 0.62 μIU/ml were calculated as 2.60 (95% CIs 1.49-4.54) and 6.50 (95% CIs 3.51-12.03), respectively. There was also a greater risk of thyroid cancer in patients with fT3 levels of 1.57-3.00 pg/ml, compared with patients with fT3 levels of 3.89-4.71 pg/ml (OR 2.95, 95% CIs 1.68-5.20). For fT4, OR for the risk of thyroid cancer between 0.85 and 1.17 ng/dl compared with 1.48-1.78 ng/dl was 2.14 (95% CIs 1.22-3.74). In conclusion, lower fT3, fT4, and higher TSH concentrations within normal limits were related with increased thyroid cancer independent from sex and nodule type. Particularly, the association between lower fT3, fT4 levels and a diagnosis of thyroid cancer is a novel finding.

Evaluation of a thyroid nodule

The thyroid specialist frequently evaluates thyroid nodules because they may represent malignancy. Nodules are typically found on physical examination or incidentally when other imaging studies are performed. Malignant or symptomatic nodules that compress nearby structures warrant surgical excision. Yet, the majority of thyroid nodules are asymptomatic and benign, so the thyroid surgeon must rely on diagnostic studies to determine when surgery is indicated. Ultrasound is the preferred imaging modality for thyroid nodules, and the ultrasound guided fine-needle aspiration biopsy (FNAB) is the preferred method of tissue sampling. Nodules 1 cm or larger or nodules with suspicious sonographic appearance warrant cytologic analysis to better quantify the risk for malignancy. Molecular biomarkers are a powerful adjunct to cytology. Detecting malignancy preoperatively allows total thyroidectomy in a single operation without the need for frozen section or a second operation for completion of a thyroidectomy if malignancy is found during the initial thyroid lobectomy.