Fine-needle aspiration cytology of thyroid nodules: how useful is it?

The Similarities and Differences between Liquid-based and Conventional Methods in Evaluation of Thyroid Fine Needle Aspiration Cytologies

Aims

Thyroid nodules are one of the most frequent medical issues in endocrinology in our country and around the world. The appropriate evaluation of the nodule is critical in the management of patients. Fine needle aspiration cytology (FNAC) is one of the most accurate tools for evaluating these nodules. Conventional and liquid-based (LB) methods are available for thyroid FNAC. In this paper, we aim to determine the best cytological method for the evaluation of thyroid fine needle aspiration materials.

Settings and Design

Fine needle aspiration (FNA) materials obtained and prepared by conventional and LB methods from 310 patients were evaluated. These slides were compared in terms of 12 cytological parameters in a three-tiered system, and the kappa coefficient was calculated.

Methods and Material

Two slides were prepared from FNA samples, and the rest of the material was left in protective solution for LB cytology. Surepath was used as a LB technique. Conventional slides (CS) were left to dry in the air and stained with May Grunwald Giemsa. Slides prepared by two different techniques were compared in 12 cytomorphological parameters, and Kappa coefficients and correlations were calculated.

Statistical Analysis Used

Kappa statistics.

Results

In comparison of LB and CS, the highest kappa coefficient was in chromatin texture (ĸ:0.738) and inflammatory cells (ĸ: 0.482). On other parameters, fair or poor agreement was observed.

Conclusions

Although there are some superiorities to LB cytology, co-application of these two methods is more favorable in thyroid fine needle aspiration.

Role of fine-needle aspiration cytology in evaluating thyroid nodules. A retrospective study from a tertiary care center of Western region, Saudi Arabia

OBJECTIVES

To evaluate the accuracy and e cacy of ne-needle aspiration cytology (FNAC) in diagnosing thyroid nodules, correlating it with the histopathological findings.

METHODS

A retrospective evaluation of 314 patients was undertaken at a tertiary referral center of King Abdullah Medical City (KAMC), Makkah, Kingdom of Saudi Arabia, between 2010-2019. Patients who presented with thyroid swellings underwent ultrasonography and FNAC. If indicated, surgery was performed. The FNAC findings were compared to the final histopathological reports.

RESULTS

The findings for FNAC from our data set of 314 patients showed a sensitivity value of 79.8%, specificity of 82.1%, accuracy of 74.8%, positive predictive value of 74.8%, and negative predictive value of 85.9%. Conclusion: Our study showed that FNAC has high sensitivity and speci city in the initial evaluation of patients with thyroid nodules. When guided by ultrasonography, the accuracy can be markedly improved. Molecular markers once widely available can improve the diagnostic power of FNAC to be no less than the histopathologic evaluation of thyroid tissue.

The importance of using fine-needle aspiration cytology in the diagnosis of thyroid nodules

Background

Thyroid nodules are common diseases, frequent in middle-aged women; only 5%–30% are malignant. Fine needle aspiration cytology is a simple, rapid and non invasive diagnostic test, performed to predict malignancy and avoid unnecessary surgery.

The aim of this study is to evaluate the accuracy of fine needle aspiration in the management of thyroid lesions.

Materials and methods

Our study was retrospective, including all cases of thyroid fine needle aspiration between January 2010 and December 2017, which were verified by microscopic examination, Data was obtained from the files of Pathology and ENT Department of Farhat Hached Hospital of Sousse and from nuclear medicine department of Sahloul Hospital of Sousse, Tunisia.

Results

A total of 58 cases were studied, the main age was 40 ± 15,57 years and the sex ratio was 0.03 with female predominance. Concordance between fine needle aspiration and histology was seen in 45 cases. The sensitivity was 60% and the specificity was 100%. The negative and positive predictive values were 100 and 92%, respectively. The concordance index Kappa was of 0.67.

Conclusion

Thyroid fine needle aspiration in experienced hands is an easily performed diagnostic procedure with very little associated risk. It should be performed in suspect nodules for treatment stratification.

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The thyroid nodules are a frequent disease.

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We present a serie case of 58 thyroid nodules to enhance the importance of using of fine needle cytology to predict malignancy and avoid unnecessary surgery.

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We describe clinical, gross and microscopic examinations for diagnosis and treatment.

The Role of the ThyroSeq v3 Molecular Test in the Surgical Management of Thyroid Nodules in the Canadian Public Health Care Setting

Background: Although the current gold standard for diagnosing thyroid nodule malignancy is ultrasound-guided fine-needle aspiration (FNA) cytology, about 20-25% of cytological evaluations are considered indeterminate for malignancy. This limitation has led to the emergence of next-generation sequencing panels, for example, ThyroSeq v3 (TSv3), which recognize highly diagnostic genetic mutations of common thyroid carcinomas in FNA samples and classify them as test-negative or test-positive, helping optimize treatment for indeterminate thyroid nodules (ITNs). Our goals were to evaluate the benign call rate (BCR) of TSv3 and assess its diagnostic performance and clinical utility while highlighting the points of consideration for a public Canadian institution. Methods: This is a single-center study conducted at the Royal Victoria Hospital (McGill University Health Centre) in Montreal, Canada, between January and February 2019. Patients were offered TSv3 following the McGill algorithm for ITN workup, a novel protocol developed at our institution to select only diagnostic surgery candidates to minimize waste of public resources, considering the single-payer health care system. Patient demographics, cytopathology results, TSv3 data, treatment plan, and final histopathology result were reviewed. Results: A total of 50 ITNs underwent TSv3 testing; molecular analysis yielded 20 (40%) "positive" results and 24 (48%) "negative" results. Six (12%) results were classified as "currently negative" or "negative but limited." "Currently negative" results indicate a low-risk mutation that alone is insufficient for development of a malignant lesion. "Negative but limited" results indicate a sample that is nondiagnostic for malignancy due to low cell count. BCR was calculated as ("negative" and "currently negative")/total, resulting in a BCR of 58%. Twenty-three (46%) patients were scheduled for surgery and 27 (54%) patients continued with surveillance. Ninety-one percent (20 of 22) of the resected target nodules were malignant on final pathology. Conclusions: TSv3 proved beneficial in classifying ITNs as positive or negative, avoiding surgery in the latter cases. We found a lower reduction rate in surgery and BCR than the previously published studies, which is attributable to the criteria of the McGill algorithm. In the Canadian public health care system, preventing unnecessary surgery represents significant cost savings for the provincial government while also improving patient quality of life.

Positive central lymph-nodes are underdiagnosed in patients with Bethesda V cytology in an endemic goiter region

Background

Fine needle aspiration (FNA) is a significant diagnostic procedure for detecting malignancy in patients with nodular thyroid disease. A high proportion of patients with cytological diagnosed follicular neoplasia (Bethesda IV and V) ultimately have thyroid cancer. The aim of this study was to evaluate the incidence of preoperatively undiagnosed central lymph node metastasis in patients with multinodular goiter (MNG).

Methods

Patients who underwent FNA and were classified as Bethesda IV/V were included. Applying a radical approach, all patients underwent (hemi)thyroidectomy and prophylactic unilateral central neck dissection.

Results

During our study period 2009-2013, 60 patients (19.7%) were classified as Bethesda IV and 21 (6.9%) Bethesda V. Final histopathological results revealed malignancy in 35 (43.2%) of 81 Bethesda IV/V nodules. Of the nodules classified as Bethesda IV, 20 (33.3%) showed malignancy in the final histology. Ten patients (16.7%) had papillary micro-carcinoma (mPTC, <10 mm), 4 (6.6%) PTC and 6 (10%) follicular thyroid cancer. Fifteen of 21 (71.4%) Bethesda V nodules were revealed as PTC of whom seven (33.3%) patients also had lymph-node metastases.

Conclusions

While 33.3% of the patients with PTC, preoperatively classified as Bethesda V, had previously undetected positive lymph-nodes, only one patient with Bethesda IV had lymph-node metastasis.

A Comparison of the Diagnostic Efficiency of Guided Fine Needle Aspiration Cytology Versus Conventional Fine Needle Aspiration Cytology of the Thyroid

Fine needle aspiration cytology (FNAC) is possibly the most useful investigation for the thyroid. However, conventional FNAC (C-FNAC) is limited by a high rate of inadequate samples. Ultrasound guided FNAC (US-FNAC) has been proposed as an alternative. This study aims to estimate the measures of diagnostic accuracy of FNAC as well as to compare US-FNAC against C-FNAC. Patients who underwent FNAC at our for a period of 5 years were selected. This comprised of 237 C-FNAC cases and 173 US-FNAC cases. Out of these 410 cases, 129 cases had cyto-histological correlation. The proportion of inadequate samples, malignant cases as well as indeterminate cases were compared between US-FNAC and C-FNAC. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), likelihood ratios for positive and negative results and odds ratio were estimated for overall FNAC as well as US-FNAC and C-FNAC patients. US-FNAC has a significantly lower proportion of inadequate samples (0.58 vs. 15.19%), as well as a lower proportion of indeterminate samples (1.7 vs. 7.6%) and a higher proportion of malignant cases (6.4 vs. 2.1%). When the inadequate samples were excluded, the results for tests of diagnostic effectiveness for overall FNAC, US-FNAC and C-FNAC respectively ranged between 66.67 and 80% for sensitivity, between 86.05 and 100% for specificity, between 45.45 and 100% for PPV and between 97.37 and 98.7% for NPV. FNAC is a useful test for differentiating malignant from benign lesions. When inadequate samples are excluded, both US-FNAC and C-FNAC are accurate diagnostic tests. However, US-FNAC is a more useful test since it results in a lower number of inadequate samples. Also, US-FNAC results in a greater yield of malignancy and a lower percentage of indeterminates, possibly due to additional information received from ultrasound examination.

Preoperative Staging of Differentiated Thyroid Carcinomas: Comparison of USG and CT with Intraoperative Findings and Histopathology

To study the efficacy of USG and CECT in preoperative staging of differentiated thyroid carcinomas in comparison to the intraoperative and histopathological findings. A prospective, observational study was conducted in a tertiary care hospital over a period of one and a half years where USG and CECT of 23 subjects with histopathologically proven differentiated thyroid malignancy were analysed to study the characteristics of the primary tumour, lymphatic metastasis and evaluate the sensitivity and specificity of the radiological investigations in comparison to the intra-operative and histopathological findings. When compared with intraoperative and histopathological T-staging, USG had an accuracy of 69.5% and 73.9% and CECT had an accuracy of 78.2% and 73.9% respectively. The sensitivity and specificity of USG and CECT in determining a malignant nodule was 71.4% and 33.3% and 52.4% and 66.7% respectively. The N-staging according to the histopathological examination findings was in agreement with that of USG in 65.2% and CECT in 65.2% patients. The sensitivity and specificity of USG was 94.4% and 41.7% and that of CECT was 92.2% and 44.4% respectively in detecting lymphatic metastasis. The sensitivity and specificity of USG was 94.4% and 44.4% and that of CECT was 92.2% and 27.3% respectively in detecting lateral compartment lymphatic metastasis. USG identifies the characteristics of the malignant nodules better and CECT has a higher identifying central compartment lymphatic metastasis. CECT should be used as an adjunct to ultrasound to determine the extent of lymphatic metastasis and staging of disease.

Predictivity of clinical, laboratory and imaging findings in diagnostic definition of palpable thyroid nodules. A multicenter prospective study

PURPOSE

To assess the role of clinical, biochemical, and morphological parameters, as added to cytology, for improving pre-surgical diagnosis of palpable thyroid nodules.

METHODS

Patients with a palpable thyroid nodule were eligible if surgical intervention was indicated after a positive or suspicious for malignancy FNAC (TIR 4-5 according to the 2007 Italian SIAPEC-IAP classification), or two inconclusive FNAC at a ≥3 months interval, or a negative FNAC associated with one or more risk factor. Reference standard was histological malignancy diagnosis. Likelihood ratios of malignancy, sensitivity, specificity, negative (NPV), and positive predictive value (PPV) were described. Multiple correspondence analysis (MCA) and logistic regression were applied.

RESULTS

Cancer was found in 433/902 (48%) patients. Considering TIR4-5 only as positive cytology, specificity, and PPV were high (94 and 91%) but sensitivity and NPV were low (61 and 72%); conversely, including TIR3 among positive, sensitivity and NPV were higher (88 and 82%) while specificity and PPV decreased (52 and 63%). Ultrasonographic size ≥3 cm was independently associated with benignity among TIR2 cases (OR of malignancy 0.37, 95% CI 0.18-0.78). In TIR3 cases the hard consistency of small nodules was associated with malignity (OR: 3.51, 95% CI 1.84-6.70, p < 0.001), while size alone, irrespective of consistency, was not diagnostically informative. No other significant association was found in TIR2 and TIR3.

CONCLUSIONS

The combination of cytology with clinical and ultrasonographic parameters may improve diagnostic definition of palpable thyroid nodules. However, the need for innovative diagnostic tools is still high.

Ultrasound-guided fine needle aspiration of thyroid nodules: factors affecting diagnostic outcomes and confounding variables

Background The incidence of thyroid cancer is increasing in men and women. Fine needle aspiration (FNA) is an accepted technique to assess thyroid nodules but is associated with a high rate of non-diagnostic sampling. Purpose To assess the diagnostic performance of ultrasound-guided FNA of thyroid nodules and identify factors associated with non-diagnostic sampling. Material and Methods A retrospective review of thyroid FNAs was performed between 2006 and 2013. Patient demographics, nodule characteristics, procedural technique, cytology, and complications were recorded. Cytology was categorized THY1-5 based on the British Thyroid Association guidelines. Descriptive and multivariable analysis were conducted to identify factors associated with non-diagnostic sampling. Results A total of 724 procedures were identified with 597 (82.5%) in women, and an overall mean age of 40 years (age range, 17-87 years). Factors associated with a non-diagnostic outcome in the multivariable regression analysis included increasing lesion depth (OR, 1.05 per mm; 95% confidence interval [CI], 1.007-1.10), age (OR, 1.012 per year; 95% CI, 1.0-1.025) and number of FNA passes (1 vs. 4+; OR, 6.07; 95% CI, 2.27-16.21). The complication rate was 1.1% related to perilesional hematomas and vaso-vagal episodes. Conclusion Thyroid FNA is a safe and reliable procedure for cytological assessment of thyroid nodules. Deeper nodules and older patients are more likely to have non-diagnostic samples.

Improving Access to Image-guided Procedures at an Integrated Rural Critical Access Hospital: Ultrasound-guided Thyroid Biopsy Program

PURPOSE

Critical access hospitals face difficulty providing all services locally and may need to refer patients off-site for additional care. Providing on-site minimally invasive biopsies, may obviate visits to tertiary or quaternary care centers. This study aims to assess feasibility and outcomes of an ultrasound-guided thyroid biopsy program in a critical access hospital.

METHODS

In this HIPAA compliant, IRB approved study, the Interventional Radiology (IR) database of a 19-bed, island, rural, critical access hospital without onsite pathology services affiliated with our quaternary care institution was retrospectively reviewed to identify all thyroid biopsies that were performed on site since inception of the service in April 2014 through August 2016. A specialized biopsy and specimen collection protocol was created as each specimen was transferred to and analyzed by the pathology department at our affiliated quaternary care institution.

RESULTS

Two IR physicians carried out thyroid biopsies on 34 nodules in 29 patients during the study period. The mean age of patients was 56.5 ± 14.0, with a range of 35-85 and 86% female, 14% male. 94.1% of nodules had adequate material for interpretation on the first biopsy and 97.1% upon repeat biopsy. Ultimately, 5 patients (with 6 nodules) underwent surgical resection at the integrated quaternary care center. Surgical resection identified one atypical follicular adenoma, one follicular variant of papillary thyroid carcinoma, two papillary carcinomas, and two Hürthle cell tumors.

CONCLUSION

IR thyroid biopsy services may be successfully provided in the rural setting without onsite pathology analysis and adequacy checks, enhancing patient access and streamlining care while also expanding the reach of tertiary care centers.

Comparison of 1869 thyroid ultrasound-guided fine-needle aspiration biopsies between general surgeons and interventional radiologists

BACKGROUND

Thyroid nodules are commonly encountered problems in clinical practice. For patients who have a thyroid nodule, the fine-needle aspiration biopsy (FNAB) is the most important test, as it is the most reliable diagnostic method for distinguishing between benign thyroid nodules and cancerous nodules. FNAB is able to be performed either via an ultrasound (USG) or alone and is the first choice when it comes to diagnosing thyroid nodules, given that it is cheap, safe and provides accurate results.

OBJECTIVE

In this study-a retrospective analysis of FNAB via USG - our aim is to evaluate the multiple variables related to FNAB procedures, including the experience of the person performing the biopsy, the age and gender of the patient, the number of nodules, the size of the nodule(s) and the number of lams recorded from the cytopathology report on non-diagnostic rates, conducted at an invasive radiology clinic and at a general surgery clinic.

MATERIALS AND METHODS

A total of 1062 patients involving 1869 nodules, examined using FNAB via USG, were reviewed retrospectively from records dated between November 2011 and July 2014 and from pathology reports taken from the ANEAH General Surgery clinic and Interventional Radiology clinic. Cytopathology results were classified according to the 2007 Bethesda System for Reporting. Gender, age, number of nodules, diameter of the nodules, biopsied nodules, location of the nodules, number of lams, symptoms and the date of biopsies were the parameters used to examine the factors involved in non-diagnostic cytopathology invasive radiology. These parameters were inspected at both of the clinics (ANEAH General Surgery clinic and Interventional Radiology clinic). In analyzing the results, the statistical significance level was set at 0.05, where in cases that the p value was under 0.05 (p < 0.05), it was determined that no significant relationship existed. In this study, data were analyzed using SPSS 20 software.

RESULTS

Of the nodules reviewed, 1620 were found on females and 249 on males. The age of the patients ranged from 10 to 87 years, with the mean age being 50 years. In the general surgery clinic, 470 nodules of 341 patients were aspirated, and in the interventional radiological clinic, 1399 nodules of 721 patients were aspirated. In the literature review conducted to compare statistical assessments of FNAB via USG, no significant difference was found between the ANEAH General Surgery clinic and the Invasive Radiology clinic (p > 0.05). In the invasive radiology clinic, non-diagnostic rates decreased with the increase in experience of the person who conducted the biopsy (p = 0.001).

CONCLUSION

The results from both of the clinic's rates of non-diagnostic FNAB, performed via USG, were found to be acceptable. Our study also demonstrates that USG-guided FNAB can be performed with a low non-diagnostic rate as experience grows.

Thyroid fine needle aspiration biopsy: do nodule volume and cystic degeneration ratio affect specimen adequacy and cytological diagnosis time?

BACKGROUND

A fine needle aspiration biopsy (FNAB) of thyroid nodules - the least invasive and most accurate method used to investigate malignant lesions - may yield non-diagnostic specimens even under ultrasonographic guidance.

PURPOSE

To evaluate the effects of thyroid nodule volume and extent of cystic degeneration on both the non-diagnostic specimen ratio as well as cytopathologist's definitive cytological diagnosis time.

MATERIAL AND METHODS

In this single center study, FNAB was performed on 505 patients with single thyroid nodules greater than 10 mm. Nodule volume was calculated prior to FNAB and cystic degeneration ratio was recorded. All biopsies were performed by a single radiologist who also prepared specimen slides. Specimen adequacy and final diagnosis were made in the pathology laboratory by a single-blinded cytopathologist based on the Bethesda system. Definitive cytological diagnosis time was recorded upon reaching a definitive diagnosis.

RESULTS

The specimen adequacy ratio was 85.3%. The mean nodule volume of adequate specimens was larger than those of non-diagnostic samples (6.00 mL vs. 3.05 mL; P = 0.001). There was no correlation between nodule volume and cytopathologist's definitive cytological diagnosis time (r = 0.042). Biopsy of predominantly solid nodules yielded better specimen adequacy ratios compared to predominantly cystic nodules (87.8% vs. 75.3%; P = 0.028). Definitive cytological diagnosis times were longer in predominantly cystic nodules compared to predominantly solid nodules (376 s vs. 294 s; P = 0.019).

CONCLUSION

Predominantly cystic nodules are likely to benefit from repeated nodular sampling until the specimen is declared adequate by an on-site cytopathologist. If a cytopathologist is not available, obtaining more specimens per nodule may achieve desired adequacy ratios.

Renal clear cell carcinoma with thyroid and parotid metastases: A case report

The present study reports a rare case of a renal clear cell carcinoma with thyroid and parotid metastases. A 56-year-old female, with a painless, right preauricular mass present for 6 months was referred to Renji Hospital (Shanghai, China). Physical examination revealed a mass of 3×3 cm, which was smooth, firm, immobile and non-tender. There was no accompanying facial weakness. Parotid ultrasonography revealed a hypoechoic mass within the right parotid gland, which was potentially a parotid mixed tumor. In July 2011, the patient underwent a superficial parotidectomy with preservation of the facial nerve. Pathology confirmed as right parotid clear cell carcinoma (metastasis). The patient's relevant medical history included a right radical nephrectomy for renal clear cell carcinoma (clinical stage III) in 2004. Additionally, in 2009, the patient underwent a resection of thyroid metastatic renal cell carcinoma. To the best of our knowledge, no similar case has previously been reported in English-language literature. The present study discusses a case report, and investigates the clinical features and treatment strategy.

Fine needle aspiration: an atraumatic method to diagnose head and neck masses

Background

Patients presenting with a mass require tissue biopsy for histological diagnosis and treatment. Fine needle aspiration (FNA) is offered as an atraumatic, well tolerated, and inexpensive method for obtaining a biopsy from these lesions.

Objectives

In this study we evaluated the accuracy of FNA as an atraumatic method among patients with nonthyroidal masses for diagnosis of neoplastic masses compared to open surgery.

Patients and Methods

In a cross-sectional study, 65 patients with a head and neck masses (nonthyroidal) referred to us from 2004 to 2009. Those who had both FNA and open biopsy (the gold standard) were assessed for specificity, sensitivity, positive and negative predictive values of FNA in diagnoses.

Results

Sixty-five cases with both definite diagnoses of open biopsy and FNA were assessed. The mean (± standard deviation) age of patients was 39.96 ± 19.69 years (range 10 to 82 years). Twenty-five (40.8%) subjects were categorized as malignant neoplasms, 16 (19.4%) as benign neoplasms, and 24 (39.8%) as non-neoplastic lesions. The sensitivity, specificity, positive and also negative predictive values of FNA in the diagnosis of neoplastic masses were 95%, 85%, 92.68%, and 91.66% respectively, and the diagnostic accuracy was 92.3%.

Conclusions

It seems that FNA is a useful atraumatic diagnostic technique with a high diagnostic accuracy which can provide a highly sensitive diagnosis with low false positive diagnoses in patients with nonthyroidal masses.

Prevalence and Prediction for Malignancy of Additional Thyroid Nodules Coexisting with Proven Papillary Thyroid Microcarcinoma

Objective

To investigate the clinical efficacy of ultrasonographic (US) classification of additional thyroid nodules coexisting with proven papillary thyroid microcarcinoma (PTMC).

Study Design

Historical cohort study.

Setting

Tertiary care institution.

Subjects and Methods

In addition to the prevalence of additional thyroid nodules based on an US classification, the diagnostic accuracy and predictive factors for malignancy were assessed in 300 nodules randomly selected from 300 patients with cytologically proven PTMC who underwent total thyroidectomy.

Results

The most common thyroid nodules were “indeterminate nodules,” 68.0%, followed by “probably benign nodules,” 20.7%, and “suspicious malignant nodules,” 11.3%. For indeterminate nodules, the malignancy rate was 16.6% (34/204) with disregard to its location, either on the contralateral (15.1%, 16/106) or ipsilateral side (18.4%, 18/98) of the known PTMC ( P = .53). According to univariate and multivariate analyses of clinical and US findings for predictive variables of malignancy in indeterminate nodules, hypoechogenicity was proven to be the sole predictive factor for malignancy (odds ratio 5.62, 95% CI, 2.29-13.72).

Conclusion

US-based classification of additional thyroid nodules is a useful tool for decision making of the surgical extent in patients with a single PTMC.

Cost-effectiveness of using a molecular diagnostic test to improve preoperative diagnosis of thyroid cancer

OBJECTIVE

Fine-needle aspiration biopsy (FNAB) is a safe and inexpensive diagnostic procedure for evaluating thyroid nodules.Up to 25% of the results from an FNAB, however, may not be diagnostic or may be indeterminate, leading to a subsequent diagnostic thyroid surgery. A new molecularly based diagnostic test could potentially reduce indeterminate cytological results and, with high accuracy, provide a definitive diagnosis for cancer in thyroid nodules. The aim of the study was to estimate the cost-effectiveness of utilizing a molecular diagnostic (DX) test as an adjunct to FNAB, compared with NoDX, to improve the preoperative diagnosis of thyroid nodules.

METHODS

We constructed a patient-level simulation model to estimate the clinical and economic outcomes of using a DX test compared with current practice (NoDX) for the diagnosis of thyroid nodules. By using a cost-effectiveness framework, we measured incremental clinical benefits in terms of quality-adjusted life-years and incremental costs over a 10-year time horizon.

RESULTS

Assuming 95% sensitivity and specificity of the Dx test when used as an adjunct to FNAB, the utilization of the DX test resulted in a gain of 0.046 quality-adjusted life-years (95% confidence interval 0.019-0.078) and a saving of $1087 (95% confidence interval $691-$1533) in direct costs per patient. If the cost of the Dx test is less than $1087 per test, we expect to save quality-adjusted life-years and reduce costs when it is utilized. Sensitivity of the DX test, compared with specificity, had a larger influence on the overall outcomes.

Investigating the value of fine needle aspiration cytology in thyroid cancer

Background:

Current guidance recommends the use of fine needle aspiration cytology (FNAC) as an essential investigation in patients presenting with a thyroid lump. Current literature suggests that the sensitivity of FNAC in thyroid nodules ranges between 80-90%. However, only very few studies have looked specifically at the sensitivity of FNAC in solely thyroid cancer patients.

Aims:

The aim of our study was to investigate the value of FNAC as a first-line investigation in patients with thyroid cancer. We aimed specifically to assess the sensitivity of FNAC within this group.

Materials and Methods:

Patients diagnosed with thyroid cancer between 2000-08 were identified from a local histopathology database. Sixty-seven case notes were retrieved, retrospectively reviewed and analyzed. Analysis included results of FNAC, ultrasound scanning and final histopathological diagnosis.

Results:

Analysis of the 56 patients who underwent FNAC revealed that a cytological grading of thy3 or greater was only given to 31 cases (55.3%).

Conclusion:

In this study, FNAC findings of thy3 or greater were reported only in 55.3% of proven thyroid cancer cases. This study highlights the greater diagnostic difficulties of thyroid cancer compared to other thyroid nodules. Our findings suggest that clinicians must interpret the results of this initial investigation with caution and consider the routine use of ultrasound scanning to help guide FNAC.

The impact of implementation of the Bethesda System for Reporting Thyroid Cytopathology on the quality of reporting, "risk" of malignancy, surgical rate, and rate of frozen sections requested for thyroid lesions

BACKGROUND

The Bethesda System for Reporting Thyroid Cytopathology (TBSRTC) has been anticipated to improve communication between pathologists and clinicians and thereby patient outcomes. In the current study, the impact of TBSRTC on various quality and outcome measures was assessed.

METHODS

The current study included all patients who underwent fine-needle aspiration (FNA) of the thyroid between April 2006 and April 2009. Before implementation, the authors used generic diagnostic categories; after implementation, TBSRTC was used. Quality of reporting, diagnostic categories, rate of surgery, rates of frozen section, the "risk" of malignancy after a cytologic diagnosis, and errors before and after implementation of TBSRTC were compared using the chi-square and Fisher exact tests. Multilevel likelihood ratios and the receiver operating characteristic were used to compare the accuracy of FNA before and after implementation.

RESULTS

A total of 1671 FNAs (957 obtained before and 714 obtained after implementation of TBSRTC) were obtained from 1339 patients. Of these, 301 patients (191 before and 110 after implementation) underwent subsequent surgical resection. Before implementation, the reports were more ambiguous (3.7% vs 0.5%; P < .05) and implicit (5.1% vs 2.7%; P < .05) than after implementation. The overall rate of surgery decreased after implementation of TBSRTC (24.5% vs 19.6%; P < .05). The overall risk of malignancy did not appear to be affected by implementation of TBSRTC, but it decreased significantly after a benign FNA diagnosis compared with a diagnosis of an atypical lesion or follicular neoplasm. The rate of frozen section remained unchanged. The diagnostic accuracy was not found to be significantly different before compared with after implementation of TBSRTC.

CONCLUSIONS

Implementation of TBSRTC appears to improve the quality of reporting by lowering the number of ambiguous and implicit diagnoses and decreases the overall surgery rates, particularly for benign lesions, but it does not appear to have any effect on the accuracy of FNA of the thyroid, false-positive rates, or the frequency of intraoperative consultations.

Predictive value of cytologic atypia in indeterminate thyroid fine-needle aspirate biopsies

BACKGROUND

Fine-needle aspiration (FNA) biopsies are the most accurate method for diagnosis of thyroid nodules. Unfortunately, biopsies are indeterminate 15-30% of the time and surgery is thus required for a definitive diagnosis. We aimed to determine whether specific descriptors of cytologic atypia mentioned in indeterminate FNA reports were associated with malignancy on final histopathology.

METHODS

Retrospective review of 1000 surgery patients identified 466 indeterminate FNA lesions that underwent either a hemi- or total thyroidectomy between 1998 and 2009. We screened FNA reports for specific descriptors of nuclear atypia. Univariate and multivariate analyses were performed to evaluate the independent effect of cytologic atypia descriptors on the risk of malignancy.

RESULTS

Nuclear atypia on FNA conferred a risk of malignancy of 42% (P < 0.0001). Risk of malignancy increased from 17% for zero descriptors to 81.2% when four or more descriptors of atypia were described. Nuclear grooves and inclusions together conferred a risk of malignancy, specificity, and false positive rate of 79.3%, 98.2% and 1.8% respectively.

CONCLUSIONS

The presence of four or more descriptors of cytologic atypia or the presence of both nuclear inclusions and grooves together confers a high risk of malignancy on final histopathology and a low false positive rate. These findings should be taken into consideration when interpreting FNA reports and total thyroidectomy should be considered for those patients at higher risk.

The role of fine-needle aspiration cytology in the surgical management of thyroid cancer

BACKGROUND

Diagnosis of thyroid malignancy relies on clinical assessment, imaging and fine-needle aspiration cytology 'FNAC' of thyroid nodules. The purpose of this study was to evaluate how effective synoptically reported FNAC is in clinical practice in diagnosing thyroid cancer. We also examined the effectiveness of using preoperative FNAC results to plan the type of operation for treating thyroid cancer.

METHOD

A retrospective case series of all patients undergoing thyroid surgery from 1993 to 2008 was analysed. All data were collected prospectively and recorded in a dedicated endocrine surgery database. Data analysed included age, sex, preoperative FNAC result, type of surgery, final histology and complications. Cytology was reported based on a five-tiered classification system.

RESULTS

There were 1373 patients in total and 125 patients with a final diagnosis of thyroid cancer. Female to male ratio was 3:1. Cytology reported as 'malignant' was confirmed as thyroid cancer in 100% of the cases. Of the patients, 47% with 'suspicious' cytology report and 14% with 'follicular/indeterminate' cytology report had a final diagnosis of cancer. Thyroid cancer subtypes were 90 patients with papillary thyroid cancer 'PTC', 24 with follicular 'FTC', eight with medullary 'MTC' and two with anaplastic cancer. Cytology was suggestive of cancer in 89% of the patients with PTC >10 mm, 75% with FTC and 88% with MTC. Transient hypocalcaemia was the commonest complication occurring in 7.2%. There were no cases of permanent hypoparathyroidism. Recurrent laryngeal nerve neuropraxia occurred in 2.4% with a permanent palsy occurring in 0.8%. There were three cancer-related deaths.

CONCLUSIONS

Preoperative synoptically reported FNAC is effective when used in diagnosing and planning surgery for thyroid cancer.

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.

‘Ad Hoc Sternal-Split Safely Replaces Full Sternotomy for Thyroidectomy Requiring Thoracic Access

Mediastinal goiter (MG) removal occasionally needs sternotomy, mainly in case of subaortic extension. We aimed to test the hypothesis that sternal-split may safely replace full sternotomy for MG removal (through total thyroidectomy) when thoracic access is required. We conducted a prospective observational cohort study comparing 15 subaortic MGs receiving sternal-split with 87 MGs undergoing cervicotomy alone between January 1997 and June 2009. Among 15 cases requiring sternal incision, sternal-split was extended to the angle of Louis in nine patients (60%), to the third intercostal space (IS) in one of five (20%) cases of MGs with anterior mediastinum involvement, and in five of 10 (50%) cases with posterior involvement ( P = 0.6). Full sternotomy was never necessary. The median hospitalization was 5 days (range, 4-8 days) after sternal access as compared with 3 days (range, 2–4 days) after cervicotomy ( P = 0.04). Complications were similar in these two study groups: one postoperative bleeding in each group and three recurrent laryngeal nerve palsies after cervicotomy ( P = 0.5). There was no operative mortality, blood transfusion, tracheotomy requirement, wound infection, or persistent hypoparathyroidism. Proper extension of sternal-split to the second or third IS allows an adequate approach to both the anterior and to the posterior mediastinum, thus permitting safe management of MGs requiring thoracic access.

A New Fine-Needle Aspiration System

Background. The main reasons for fine needle aspiration (FNA) failure are insufficient number of cells in the sample, nonrepresentative samples, and contamination of samples. The aim of this study was to measure the number of cells harvested by a new needle system with an aeration aperture (Thyrosampler) in comparison with a conventional FNA system (C-FNA). Methods. Under a double-blind setting, 30 aspirations, 15 with each system (C-FNA, Thyrosampler), were done in randomized order and recorded. Results. The median total number of cells was 59 680 cells/mL with C-FNA and 396 400 cells/mL with Thyrosampler. The needle system with the aeration aperture led to a significantly higher cell amount (564% more cells than the conventional system; P < .005) in needle aspiration biopsy. Conclusion. The new system with the vacuum release feature leads to a significantly higher cell amount in needle aspiration biopsy, which is a well-defined benefit.

Correlation of fine needle aspiration cytology with histopathology in the diagnosis of solitary thyroid nodule

Background. Fine needle aspiration cytology is considered the gold standard diagnostic test for the diagnosis of thyroid nodules. Fine needle aspiration cytology is a cost effective procedure that provides specific diagnosis rapidly with minimal complications. Based on the cytology findings, patients can be followed in cases of benign diagnosis and subjected to surgery in cases of malignant diagnosis thereby decreasing the rate of unnecessary surgery. Purpose of the present study was to correlate the fine needle aspiration cytology findings with histopathology of excised specimens. Material and Methods. This was a prospective study conducted on 75 consecutive patients between January 2003 and December 2005. All patients with clinically diagnosed solitary thyroid nodule who were clinically and biochemically euthyroid were included for study. Patients with multinodular goitre and who were hypothyroid or hyperthyroid were excluded from the study. Results. The sensitivity, specificity, accuracy, false positive rate, false negative rate, positive predictive value, and negative predictive value of FNAC for the diagnosis of neoplastic solitary thyroid nodules were 80%, 86.6%, 13.3%, 20%, 80%, and 86.6%, respectively. Commonest malignancy detected was papillary carcinoma in 12 patients. Conclusions. Fine needle aspiration cytology is a simple, easy to perform, cost effective, and easily repeated procedure for the diagnosis of thyroid cancer. It is recommended as the first line investigation for the diagnosis of solitary thyroid nodule.

Indeterminate thyroid nodules: a challenge for the surgical strategy

BACKGROUND

Because no clinical parameter can establish the final status of a cytologically indeterminate thyroid nodule (ITN) or nodal-metastases in case of malignancy, the initial surgical strategy should define an oncologically adequate procedure with low morbidity.

METHODS

The prognostic relevance of sex, age, tumor sizes, multifocality, thyroid function, and recurrence was analyzed in 156 consecutive patients according to the presence of malignancy and nodal metastases. The accuracy of frozen sections to reveal malignancy was determined. Clinical parameters were compared with regard to their ability to identify malignancy and nodal metastases in an ITN to determine an appropriate initial operative strategy.

RESULTS

One hundred and eighteen (75.6%) patients underwent (total) thyroidectomy, 37 (23.7%) patients underwent hemithyroidectomy, and 1 patient underwent isthmus resection. Fifty-five (35.3%) patients showed malignancy. First step lymphadenectomy (lymph node dissection along the recurrent laryngeal nerve before removing the thyroid lobe) was performed in 142 patients documenting 10 nodal metastases. Comparing benign and malignant ITN, no association was found for sex (P = .17), age (P = 1.0), tumor sizes (P = .33, P = .12, P = .19 for < or =30 mm, < or =40 mm, and < or =50 mm, respectively), or thyroid function (P = .26). The determination of malignancy by frozen section showed a sensitivity of 30.9% and a specificity of 100%. No permanent hypoparathyroidism or recurrent laryngeal nerve palsy was observed postoperatively.

CONCLUSION

Because of the failure of available clinical parameters to predict malignancy in cytologically ITN, hemithyroidectomy in unilateral goiter and thyroidectomy in bilateral goiter is recommended. Ipsilateral "first step central neck dissection" on the side of ITN offers the advantages of oncologically adequate resection and staging with a low morbidity, as well as avoids reoperation.

How to approach thyroid nodules with indeterminate cytology

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

How to interpret thyroid biopsy results: a three-year retrospective interventional radiology experience

Results of thyroid biopsy determine whether thyroid nodule resection is appropriate and the extent of thyroid surgery. At our institution we use 20/22-gauge core biopsy (CBx) in conjunction with fine-needle aspiration (FNA) to decrease the number of passes and improve adequacy. Occasionally, both ultrasound (US)-guided FNA and CBx yield unsatisfactory specimens. To justify clinical recommendations for these unsatisfactory thyroid biopsies, we compare rates of malignancy at surgical resection for unsatisfactory biopsy results against definitive biopsy results. We retrospectively reviewed a database of 1979 patients who had a total of 2677 FNA and 663 CBx performed by experienced interventional radiologists under US guidance from 2003 to 2006 at a tertiary-care academic center. In 451 patients who had surgery following biopsy, Fisher's exact test was used to compare surgical malignancy rates between unsatisfactory and malignant biopsy cohorts as well as between unsatisfactory and benign biopsy cohorts. We defined statistical significance at P = 0.05. We reported an overall unsatisfactory thyroid biopsy rate of 3.7% (100/2677). A statistically significant higher rate of surgically proven malignancies was found in malignant biopsy patients compared to unsatisfactory biopsy patients (P = 0.0001). The incidence of surgically proven malignancy in unsatisfactory biopsy patients was not significantly different from that in benign biopsy patients (P = 0.8625). In conclusion, an extremely low incidence of malignancy was associated with both benign and unsatisfactory thyroid biopsy results. The difference in incidence between these two groups was not statistically significant. Therefore, patients with unsatisfactory biopsy specimens can be reassured and counseled accordingly.

Quality improvement by standardization of procurement and processing of thyroid fine-needle aspirates in the absence of on-site cytological evaluation

BACKGROUND

Thyroid nodules are relatively common and are routinely evaluated by fine-needle aspiration cytology, usually performed by clinicians. We noticed qualitative and/or quantitative variability in samples submitted to the cytopathology laboratory from clinicians, for example, the number of glass slides submitted (2-25) and air-dried smears versus alcohol-fixed slides, with variability in specimen adequacy and interpretability. The objective of this study was to standardize the preanalytic variables to determine if there is an improvement in the specimen quality.

METHODS

We standardized the method of collection (ultrasound-guided, 25-gauge needle, four passes) and preparation of samples (four total smears: two air-dried, two fixed, with liquid-based preparation and/or cell block) and personnel involved.

RESULTS

Standardization of thyroid nodule fine-needle aspiration and sample preparation by clinical staff resulted in an overall improvement in the quality of sample (odds ratio = 3.82, 95% confidence interval 2.02-7.24, p < 0.0001) with an increased proportion of satisfactory samples from 67% prestandardization to 89% poststandardization.

CONCLUSIONS

Standardization resulted in a significant improvement in specimen interpretability.

Fine-needle aspiration biopsies in the management of indeterminate follicular and Hurthle cell thyroid lesions

Objectives: To determine the value of fine-needle aspiration biopsies (FNABs) of the thyroid and stratify the risk of malignancy within the indeterminate FNAB diagnostic category at our institution.

Study design: Case series with chart review of preoperative FNABs of consecutive patients who underwent total thyroidectomy between 2005 and 2007.

Subjects and Methods: A total of 115 cases were reviewed, and FNABs were categorized into four groups: benign, positive or suspicious for malignancy, indeterminate (follicular or Hurthle cell lesions), and nondiagnostic. Cytohistologic correlation was then established.

Results: The accuracy of FNAB in detecting thyroid malignancy was 88 percent with false-negative and false-positive rates of 13 percent and 7 percent, respectively. Overall, 52 percent of the indeterminate cases were carcinomas (48 percent of follicular lesions and 62 percent of Hurthle cell lesions). In the presence of cytologic atypia, the rate of malignancy increased to 75 percent and 83 percent for the follicular and Hurthle cell lesions, respectively.

Conclusions: FNAB is an accurate and helpful method for the evaluation of thyroid nodules with results directly correlating with management. Surgery should be considered for FNABs categorized as indeterminate, especially in the presence of cytologic atypia. Because of the high false-negative rate, benign FNABs require close follow-up with ultrasound examination and periodic biopsies.

A comparative study of fine needle aspiration and fine needle non-aspiration biopsy on suspected thyroid nodules

Ultrasonography-guided fine needle aspiration (FNA) and fine needle non-aspiration (FNNA) biopsy were performed consecutively on 104 patients (mean age 50 +/- 15 years) affected by multinodular and uninodular goiter. Both techniques were executed on the same patients in the same clinical session beginning with the first (FNA) on half of the patients (randomly selected) and vice versa. The cytological findings on cell samples were divided into four groups: colloidal (benign), follicular (suspicious), malignant, and inadequate. The overall cytologic findings obtained with the two techniques were as follows (FNA % vs FNNA %): inadequate, 16.3% vs 5.8%; colloidal, 69.2% vs 76.9%; follicular, 9.6% vs 10.5%; and malignant, 4.8% vs 6.7%. A statistically significant difference between FNA and FNNA cytology was found only on the number of inadequate results (p = 0.015). Interestingly, the frequency of inadequate specimens for FNNA showed a significantly different distribution depending on the sequence (first or second) in which the technique was executed. In conclusion, FNA and FNNA are useful and cost-effective techniques for the pre-operative assessment of patients with thyroid nodules. However, due probably to its minimally invasive procedure, FNNA produces specimens of better quality and reduces inadequate results. For these reasons FNNA should be preferable to FNA for the cytological evaluation of thyroid nodules.

A diagnostic predictor model for indeterminate or suspicious thyroid FNA samples

BACKGROUND

The management of patients with thyroid fine-needle aspiration (FNA) specimens that are neither benign nor malignant still remains problematic. Efforts to improve their management have focused on identifying risk factors that predict malignancy. This study seeks to identify clinical and tumor characteristics that predict thyroid malignancy among patients with indeterminate or suspicious FNA and to develop a diagnostic predictor model.

METHODS

The records of 639 patients with an indeterminate or suspicious thyroid FNA between January 1995 and April 2005 were reviewed. Patient and tumor characteristics were evaluated for their potential to predict malignancy in the final surgical histopathology. A diagnostic predictor model was designed based on statistically significant predictors. Patients seen between April 2005 and April 2007 were used to validate the model.

RESULTS

Patient age, nodule size, and FNA cytopathology were identified as risk factors. Patients at extremes of age were at increased risk. Patients 50 years of age had the lowest risk of malignancy. For patients less than age 50, the risk increased 3% for each year decrease in age (p = 0.001). After 50, the risk increased 3.4% for each year increase in age (p = 0.016). Nodules 2.5 cm had the lowest likelihood of malignancy. For smaller nodules, the risk increased 53% per cm decrease in size (p < 0.001). For larger nodules, the risk increased 39% per cm increase (p < 0.001). Patients with FNA cytology suspicious for papillary thyroid carcinoma had the greatest risk of malignancy (p < 0.001).

CONCLUSIONS

A predictor model was created using the variables age, nodule size, and FNA cytology to predict thyroid malignancy.

Immunohistochemical staining for thyroid peroxidase (TPO) of needle core biopsies in the diagnosis of scintigraphically cold thyroid nodules

BACKGROUND

Cold thyroid nodules are common, in particular in iodine-deficient areas, but only a minority of them are malignant requiring surgery. Thyroid peroxidase (TPO) immunostaining of fine-needle aspiration cytology (FNAC) material has proven helpful in diagnosing cells from malignant lesions, but the procedure has its limitations in a routine setting.

PURPOSE

To improve diagnosis and reduce surgery rate, the FNAC procedure was replaced by needle core biopsy (NCB), which was routinely stained for TPO by the monoclonal antibody mAb 47.

MATERIALS AND METHODS

During a 5-year period 427 consecutive patients with a cold thyroid nodule were evaluated by ultrasound-guided NCB, which had been routinely stained for TPO in an automated immunostainer. Sensitivity and specificity and predictive values of the TPO immunostaining were estimated, based on the final diagnosis obtained from surgical resection.

RESULTS

The majority of nodules with benign NCB diagnosis were not surgically removed, and thus a subgroup of 140 operated nodules formed the basis for the calculations. Sensitivity and specificity for benign and malignant lesions were 100% if the oxyphilic variant of adenomas and minimally invasive follicular carcinomas were excluded. By inclusion of these, the values fell to 89% and 97%, respectively. The predictive value of a positive test was 96% and the predictive value of a negative test was 97%.

CONCLUSION

TPO immunostaining was found to be a valuable adjunct to morphology in the diagnosis of cold thyroid nodules of the nonoxyphilic type.

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.

Fine-needle aspiration may miss a third of all malignancy in palpable thyroid nodules: a comprehensive literature review

BACKGROUND

Fine-needle aspiration (FNA) is currently the primary diagnostic procedure in diagnosing thyroid malignancy and guides surgeons on patient selection for thyroidectomy for thyroid nodules. Diagnostic sensitivity is reported to be approximately 80%; however, patients with negative FNA results do not necessarily undergo surgery and are often not considered in statistical analysis. This may lead to bias in previous reported sensitivity of FNA. The aim of this study was to assess the diagnostic performance attributes of FNA based on a comprehensive review and summary of previous literature.

METHODS

A comprehensive review of published literature from 1966 to 2005 was performed, using structured selection and appraisal methods to include all studies that have assessed the sensitivity of FNA for detecting thyroid malignancy in palpable thyroid nodules. A statistical modeling study was designed to estimate the possible true sensitivity and specificity of FNA.

RESULTS

Twelve studies fulfilled inclusion criteria and were included in the review. Only 1 study had greater than 25% of patients with negative FNA results who proceeded to thyroidectomy. Statistical modeling indicated that the sensitivity of FNA is highly dependent on the risk of malignancy in the patients with negative FNA results who did not undergo thyroidectomy; in the "same risk" scenario, where the risk of malignancy in the whole group with negative FNA result was assumed to be the same as that in patients with negative FNA results who underwent surgical biopsy; sensitivity could be as low as 66% (confidence interval [CI]: 65-68%).

CONCLUSION

Based on existing reports, the true diagnostic attributes of FNA for thyroid malignancy in palpable nodules are uncertain and FNA could miss up to a third of all thyroid malignancy. Further research is required to investigate the incidence of malignancy in FNA negative cases and to determine the additive effect of clinical judgment.

Needle track dissemination of follicular thyroid carcinoma following fine-needle aspiration biopsy: report of a case

Few reports have been concerned with the risk of needle track dissemination of tumor cells following fine-needle aspiration biopsy, especially for follicular thyroid nodules. A 61-year-old woman who underwent fine-needle aspiration biopsy and surgery 5 years previously for follicular thyroid adenoma presented with nodules that had developed in the sternocleidomastoid and omohyoid muscles of the anterior neck. These nodules were located along a line from the skin to the thyroid that coincided with the needle track of the previous biopsy. Following surgical resection, histological diagnosis determined the nodules to be follicular carcinoma. The clinical course and linear arrangement of the lesions were highly suggestive of needle track dissemination of tumor cells following fine-needle aspiration biopsy. Although fine-needle aspiration biopsy is a useful tool for the diagnosis of thyroid nodules, it is important to consider the risk of tumor cell dissemination.

Contemporary diagnostic approach to the thyroid nodule

Thyroid nodules are common, with an estimated incidence of 5%-10% in the United States. The current gold standard for diagnosis is fine needle aspiration biopsy (FNAB). The incidence of indeterminate diagnoses varies from 10% to 25%. Surgical resection is usually indicated to exclude the diagnosis of cancer in these patients. However, only a minority (about 20%) of indeterminate thyroid nodules actually harbor a malignancy, resulting in surgery for diagnostic purposes alone in many patients. The increased detection of benign nodules and microcarcinomas reinforces the need for improved non-operative methods to differentiate benign from malignant disease and discriminate low-risk from high-risk cancers. In this article we present a current, rational diagnostic approach to the patient with a thyroid nodule, evaluate new advances including thyroid genomic and predictor models, and propose the development of prospective trials to incorporate these new additions into clinical decision making. Given how many questions still exist for patients with thyroid nodules, partnership and collaboration, or the "bench to bedside" concept should find its way into most every thyroid surgeon and endocrinologist's lexicon.