Evaluation of the fine needle aspiration biopsy in the preoperative selection of cold thyroid nodules

Association between diagnostic efficacy of acoustic radiation force impulse for benign and malignant thyroid nodules and the presence or absence of non-papillary thyroid cancer: A meta-analysis

Purpose

The aim of this study was to investigate the diagnostic efficacy of Acoustic Radiation Force Impulse (ARFI) for benign and malignant thyroid nodules in the presence and absence of non-papillary thyroid cancer (NPTC) and to determine the cut-off values of Shear Wave Velocity (SWV) for the highest diagnostic efficacy of Virtual Touch Quantification (VTQ) and Virtual Touch Tissue Imaging and Quantification (VTIQ).

Methods

The diagnostic accuracy of ARFI for benign and malignant thyroid nodules was assessed by pooling sensitivity, specificity and area under the curve (AUC) in each group in the presence and absence of both non-papillary thyroid glands, using histology and cytology as the gold standard. All included studies were divided into two groups according to VTQ and VTIQ, and each group was ranked according to the magnitude of the SWV cutoff value to determine the SWV cutoff interval with the highest diagnostic efficacy for VTQ and VTIQ.

Results

A total of 57 studies were collected on the evaluation of ARFI for the diagnosis of benign and malignant thyroid nodules. The results showed that the presence of non-papillary thyroid carcinoma led to differences in the specificity of VTIQ for the identification of benign and malignant thyroid nodules, and the differences were statistically significant. In addition, the diagnostic efficacy of VTQ was best when the cutoff value of SWV was in the interval of 2.48-2.55 m/s, and the diagnostic efficacy of VTIQ was best when the cutoff value of SWV was in the interval of 3.01-3.15 m/s.

Conclusion

VTQ and VTIQ have a high diagnostic value for benign and malignant thyroid nodules; however, when the malignant nodules in the study contain non-papillary thyroid carcinoma occupying the thyroid gland, the findings should be viewed in a comprehensive manner.

Optimierung der Schilddrüsen- Feinnadelpunktion

Objective: Optimization of a specially developed automatic microaspirator for fine-needle aspiration of suspicious thyroid nodules. Patients, method: In a preliminary test biopsy effectiveness was evaluated in 20 native resected thyroid glands in vitro with both a Cameco® gun and a specially designed microaspirator respectively. In addition in both techniques two different needles (21-G and 27-G) were used to evaluate the influence of these two cannula. Subsequently, 103 thyroid nodules were biopsied in vivo and compared the results with a preliminary series of the same physician. In the workup and evaluation of the cytology the ThinPrep® technology was used. Results: In vitro the automatic microaspirator was superior to Cameco gun in both when using the 21-Gauge and the 27-Gauge needle. In terms of needle sizes a statistically significant difference at the 95% confidence level was evident for both comparisons in favor of 21-gauge needle. In vivo, 91% of punctures with the microaspirator were usable, while in the pre-series only 84% were usable (p > 0.05). Conclusion: The automatic microaspirator is superior to the manual aspiration. Moreover, under sonographic control it is more convenient, to biopsy even very small nodules and lesiosn (down to 4 mm in diameter)

Fine-needle Aspiration Biopsy of the Thyroid

Fine-needle aspiration biopsy is of primary importance in the screening of thyroid nodules. This report summarizes the results of a 7-year personal experience, compre hensive of 1,936 biopsies from 1,881 patients with single or multiple nodules. Ade quate material was obtained in 1,862 cases (96.2%) and interpreted as "negative," "suspicious," or "positive" for malignancy. Histological assessment in 311 operated cases revealed 6 false negatives and 3 false positives. The sensitivity, specificity, and accuracy of the test were 88.0%, 98.4%, and 96.2%, respectively. The predictive value was also high. These findings offer further evidence of the reliability of fine-needle aspiration biopsy in the evaluation of thyroid nodules, especially when the procedure is performed by experienced operators and close cooperation between clinicians and pathologists is established. Int J Surg Pathol 1 (3):171-176, 1994

Strain US Elastography for the Characterization of Thyroid Nodules: Advantages and Limitation

Thyroid nodules, with their high prevalence in the general population, represent a diagnostic challenge for clinicians. Ultrasound (US), although absolutely reliable in detecting thyroid nodules, is still not accurate enough to differentiate them into benign and malignant. A promising novel modality, US elastography, has been introduced in order to further increase US accuracy. The purpose of this review article is to assess the thyroid application of US strain elastography, also known as real-time elastography or quasistatic elastography. We provide a presentation of the technique, and of up-to-date literature, analyzing the most prominent results reported for thyroid nodules differentiation. The practical advantages and limitations of strain elastography are extensively discussed herein.

The use of endobronchial ultrasound-guided transbronchial needle aspiration in the diagnosis of thyroid lesions

BACKGROUND

Non-palpable thyroid nodules can be difficult to access by conventional ultrasound-guided fine needle aspiration, particularly when they are intrathoracic. Many of these patients are subject to multiple follow up scans or invasive diagnostic procedures such as mediastinoscopy or surgical resection. We aim to describe the feasibility of endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) for diagnosis of thyroid lesions.

METHODS

All EBUS-TBNA performed at our institutions from February 2010 to February 2013 were screened, and those in which a thyroid biopsy was performed were reviewed.

RESULTS

We identified 12 cases of EBUS-TBNA thyroid biopsy. Nine patients had an indication for EBUS in addition to their thyroid lesions. The median age was 64 years (range 44 to 84 years), and 10 patients were male. Median lesion size was 22.5 mm (range, 10 to 43 mm). Five lesions were strictly intrathoracic. All cases were sampled with a 22G needle and rapid on-site cytologic examination. Adequate samples were obtained in all 12 cases. Malignancy was identified in 3 of the 12 patients (metastatic breast adenocarcinoma, large B-cell lymphoma, and metastatic lung adenocarcinoma). The remaining 9 samples were deemed to be benign nodules. Seven of these were confirmed by clinical follow-up (n = 3), biopsies (n = 3), or surgery (n = 1).There were no EBUS-related complications.

CONCLUSIONS

EBUS-TBNA might be a safe and effective alternative for sampling thyroid lesions, particularly useful for those located below the thoracic inlet. Further prospective studies are required to compare its diagnostic yield and safety profile with standard techniques.

Interobserver agreement of Thyroid Imaging Reporting and Data System (TIRADS) and strain elastography for the assessment of thyroid nodules

Background

Thyroid Imaging Reporting and Data System (TIRADS) was developed to improve patient management and cost-effectiveness by avoiding unnecessary fine needle aspiration biopsy (FNAB) in patients with thyroid nodules. However, its clinical use is still very limited. Strain elastography (SE) enables the determination of tissue elasticity and has shown promising results for the differentiation of thyroid nodules.

Methods

The aim of the present study was to evaluate the interobserver agreement (IA) of TIRADS developed by Horvath et al. and SE. Three blinded observers independently scored stored images of TIRADS and SE in 114 thyroid nodules (114 patients). Cytology and/or histology was available for all benign (n = 99) and histology for all malignant nodules (n = 15).

Results

The IA between the 3 observers was only fair for TIRADS categories 2–5 (Coheńs kappa = 0.27,p = 0.000001) and TIRADS categories 2/3 versus 4/5 (ck = 0.25,p = 0.0020). The IA was substantial for SE scores 1–4 (ck = 0.66,p<0.000001) and very good for SE scores 1/2 versus 3/4 (ck = 0.81,p<0.000001). 92–100% of patients with TIRADS-2 had benign lesions, while 28–42% with TIRADS-5 had malignant cytology/histology. The negative-predictive-value (NPV) was 92–100% for TIRADS using TIRADS-categories 4&5 and 96–98% for SE using score ES-3&4 for the diagnosis of malignancy, respectively. However, only 11–42% of nodules were in TIRADS-categories 2&3, as compared to 58–60% with ES-1&2.

Conclusions

IA of TIRADS developed by Horvath et al. is only fair. TIRADS and SE have high NPV for excluding malignancy in the diagnostic work-up of thyroid nodules.

Acoustic radiation force impulse imaging for differentiation of thyroid nodules

BACKGROUND

Acoustic Radiation Force Impulse (ARFI)-Imaging is an ultrasound-based elastography method enabling quantitative measurement of tissue stiffness. The aim of the present study was to evaluate sensitivity and specificity of ARFI-imaging for differentiation of thyroid nodules and to compare it to the well evaluated qualitative real-time elastography (RTE).

METHODS

ARFI-imaging involves the mechanical excitation of tissue using acoustic pulses to generate localized displacements resulting in shear-wave propagation which is tracked using correlation-based methods and recorded in m/s. Inclusion criteria were: nodules ≥5 mm, and cytological/histological assessment. All patients received conventional ultrasound, real-time elastography (RTE) and ARFI-imaging.

RESULTS

One-hundred-fifty-eight nodules in 138 patients were available for analysis. One-hundred-thirty-seven nodules were benign on cytology/histology, and twenty-one nodules were malignant. The median velocity of ARFI-imaging in the healthy thyroid tissue, as well as in benign and malignant thyroid nodules was 1.76 m/s, 1.90 m/s, and 2.69 m/s, respectively. While no significant difference in median velocity was found between healthy thyroid tissue and benign thyroid nodules, a significant difference was found between malignant thyroid nodules on the one hand and healthy thyroid tissue (p = 0.0019) or benign thyroid nodules (p = 0.0039) on the other hand. No significant difference of diagnostic accuracy for the diagnosis of malignant thyroid nodules was found between RTE and ARFI-imaging (0.74 vs. 0.69, p = 0.54). The combination of RTE with ARFI did not improve diagnostic accuracy.

CONCLUSIONS

ARFI can be used as an additional tool in the diagnostic work up of thyroid nodules with high negative predictive value and comparable results to RTE.

Endobronchial ultrasonography with transbronchial needle aspiration to sample a solitary substernal thyroid nodule: a new approach

Sampling of solitary thyroid nodules (STNs) is a common procedure performed for cytological diagnosis. The easiest and safest method is ultrasound guided fine needle aspiration biopsy (US-FNAB). This technique is usually performed under local anaesthesia in an office setting. In contrast, sampling a substernal STN could prove to be more difficult and problematic, and sometimes requires more invasive procedures. We describe a case of substernal thyroid nodule, where malignancy was excluded using endobronchial ultrasonography with transbronchial fine needle aspiration (EBUS-TBNA). We emphasise the feasibility and safety of EBUS-TBNA in sampling retrosternal thyroid nodules. In appropriate settings, this procedure can help avoid more invasive testing, and subsequently decrease the cost and complications.

Acoustic Radiation Force Impulse-Imaging for the evaluation of the thyroid gland: a limited patient feasibility study

PURPOSE

Real-time tissue elastography, a qualitative elastography method, has shown promising results in the diagnostic work up of thyroid nodules. However, to our knowledge no study has evaluated a quantitative elastography method in the thyroid gland. The present study is a feasibility study evaluating Acoustic Radiation Force Impulse-Imaging, a novel quantitative elastography method in the thyroid gland.

METHODS

ARFI-imaging involves the mechanical excitation of tissue using short-duration acoustic pulses to generate localized displacements in tissue. The displacements induce a lateral shear-wave propagation which is tracked using multiple laterally positioned ultrasound "tracking" beams. Inclusion criteria were: thyroid nodules ≥1cm, non-functioning or hypo-functioning on radionuclide scanning, and cytological/histological assessment of thyroid nodule as reference method. All patients received conventional ultrasound, and examination of the thyroid gland including Power Doppler Ultrasound using a 9MHz linear transducer, in addition real-time elastography (RTE) was performed at 9MHz frequency and ARFI-imaging was performed at 4MHz using Siemens (ACUSON S2000) B-mode-ARFI combination transducer.

RESULTS

Sixty nodules in 55 patients were analyzed. Three nodules were papillary carcinoma. The stiffer the tissue the faster the shear wave propagates. The results obtained indicated that the shear wave velocity in thyroid lobes ranged between 0.5 and 4.9m/s. The median velocity of ARFI-imaging in the healthy nodule-free thyroid gland, as well as in benign and malignant thyroid nodules was 1.98m/s (range: 1.20-3.63m/s), 2.02m/s (range: 0.92-3.97m/s), and 4.30m/s (range: 2.40-4.50m/s), respectively. While no significant difference in median velocity was found between healthy thyroid tissue and benign thyroid nodules, a significant difference was found between malignant thyroid nodules on the one hand and healthy thyroid tissue (p=0.018) or benign thyroid nodules (p=0.014) on the other hand. Specificity of ARFI-imaging for the differentiation of benign and malignant thyroid nodules was comparable with RTE (91-95%).

CONCLUSIONS

ARFI can be performed in the thyroid tissue with reliable results.

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.

An Audit Study of the Sensitivity and Specificity of Ultrasound, Fine Needle Aspiration Cytology and Frozen Section in the Evaluation of Thyroid Malignancies in a Tertiary Institution

Introduction: The aim of this study was to conduct an audit of the sensitivity and specificity of ultrasound, fine needle aspiration cytology (FNAC) and frozen section in the evaluation of thyroid malignancies in our practice. Materials and Methods: The medical records of all the patients who underwent thyroid surgery in a tertiary institution’s General Surgery Department between January 2005 and December 2007 were retrospectively reviewed using a standardised data collection template. Results of the ultrasounds, FNACs and frozen sections were compared with the final histological diagnosis. Results: A total of 112 patients underwent thyroid surgery in the 3-year study period. Thyroid malignancy constituted 34 (30%) of all patients who underwent thyroid surgery. The most popular diagnostic tools used were ultrasound (81%), FNAC (69%) and frozen section (59%). The sensitivity of ultrasound, FNAC and frozen section were 41.4%, 86.4% and 68.8%, respectively. FNAC was shown to be a superior diagnostic test in detecting malignancy compared to ultrasound. FNAC was able to pick up 53% of thyroid cancers missed by ultrasound. Frozen section was able to pick up 33% of thyroid cancers that were missed by both ultrasound and FNAC. Conclusion: FNAC is the most reliable tool in detecting malignancies and ought to form the mainstay for investigation of thyroid nodules. The utilisation of ultrasonographic features in the evaluation of thyroid nodules might not necessary improve the detection rate of thyroid malignancy. Frozen section helps to improve the detection ate of thyroid malignancy but further studies into its cost-effectiveness ought to be performed. Key words: Investigations, Thyroid lesions

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.

Absence of microfollicular basement membrane: a new indicator in the diagnosis of follicular carcinoma thyroid

The thyroid follicles represent a biological continuum. Each follicle is closely related to the follicle that is next to it. The important feature of a follicular carcinoma is a microfollicular pattern. We report a case of follicular carcinoma in a 48-year-old female that demonstrates microfollicles which are larger in size and contain more number of follicular cells in cytologic smears (20-29 cells) in contrary to the literature definition of microfollicles containing approximately 6-12 cells. We also demonstrate absence of basement membranes in these microfollicles in histologic sections by Silver Methanamine Stain, which may be an indicator to search for vascular and capsular invasion. This case report also describes postoperative positron emission tomography scan findings.

An updated audit of fine needle aspiration cytology procedure of solitary thyroid nodule

This study was conducted to see the sensitivity, specificity, and accuracy of fine needle aspiration cytology (FNAC) for solitary thyroid nodules and to compare our experience with that of other regions of the world. It was a prospective cross sectional study conducted on 76 thyroid samples submitted and reported at the Department of Pathology, King Edward Medical University, Lahore. There were 65 (85.5%) females and 11 (14.5%) males. Male to female ratio was 1:5.9. Ages of the patients ranged from 10 to 60 year with mean age 35.37 +/- 12.17. Thirty-three (43.42%) samples were indeterminate. There were 30 cases (39.47%) of benign lesions, comprising of colloid goiter, follicular adenoma, and diffuse hyperplasia. The final reports of these cases were almost the same. On FNAC, 13 cases were declared as malignant (6 cases) or suggestive of malignancy (3 cases) or suspicious for malignancy [4 cases (5.26%)]. Only 9 cases (11.84%) were clearly committed as malignant lesions, comprising of papillary carcinoma, anaplastic carcinoma and suggestive of follicular carcinoma. Comparison of malignant cases on histopathology (14 cases) was close to that of FNAC (13 cases). After comparison of FNAC results with histopathology, overall sensitivity of FNAC was found to be 90%, specificity 87.5%, and accuracy 87%, while positive predictive value (PPV) was 93% and negative predictive value (NPV) was 79.5%. In conclusion, we recommend this procedure in the light of views of other experts as a primary investigation of thyroid lesions. We strongly recommend the suggestion that in a patient with one or more thyroid nodule, FNAC should be advised for every patient for exclusion of cancer. We will also encourage the clinicians to embrace this procedure in the initial management of patients. As FNAC is inexpensive, sensitive, specific, and an accurate procedure it should be adapted as an initial investigation of thyroid diseases in all tertiary hospitals in developing countries like Pakistan.

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.

Differential Diagnosis of Radiologically Diagnosed Thyroid Masses: Two Unusual Case Studies

Two cases of neck masses in adults are presented. In each case, imaging suggested diagnosis of a thyroid mass. Further investigation eventually found this to be at variance with the true pathology. These cases are published to illustrate the difficulties that can be encountered in delineating the organ of origin for certain neck tumours.

Incidence of Cancer in Nodular Goitres

Introduction: Nodular goitres occur commonly in the population and this paper aims to determine the incidence of thyroid cancer found in these goitres. Materials and Methods: This is a retrospective, consecutive analysis of the histology of 268 nodular goitres that had been operated on, from 2002 to 2004, in a single tertiary hospital in Singapore. Results: Fifty-seven goitres (21.2%) with multiple nodules were found to contain a malignancy. Forty-four thyroid cancers (77%) were of the papillary type. The mean age of presentation for benign nodular goitres was 47.9 years. The mean age of presentation for malignant thyroid tumours was 49.25 years. Conclusion: The incidence of cancer is significant in nodular goitres and these malignant tumours are usually of the papillary type. Key words: Goitres, Malignancy, Thyroid

Errors in thyroid gland fine-needle aspiration

Scant published data exist on redesigning pathology practice based on error data. In this first step of an Agency for Healthcare Research and Quality patient safety project, we measured the performance metrics of thyroid gland fine-needle aspiration, performed root cause analysis to determine the causes of error, and proposed error-reduction initiatives to address specific errors. Eleven cytologists signed out 1,543 thyroid gland aspirates in 2 years, and surgical pathology follow-up was obtained in 364 patients. Of the 364 patients, 91 (25.0%) had a false-negative diagnosis and 36 (9.9%) a false-positive diagnosis. Root cause analysis showed that major sources of error were pre-analytic (poor specimen quality) and analytic (interpretation of unsatisfactory specimens as nonneoplastic and lack of diagnostic category standardization). We currently are evaluating the effectiveness of error reduction initiatives that target pre-analytic and analytic portions of the diagnostic pathway.

High incidence of thyroid cancer in long-standing goiters with thyroglobulin mutations

In this paper, we report the high prevalence of thyroid malignancy in patients with thyroglobulin mutations in Japan. Mutations of the thyroglobulin gene cause defective thyroid hormone synthesis, resulting in congenital hypothyroidism. Since our report in 1999 on the thyroglobulin mutations C1264R and C1996S, we have identified 14 adult patients (7 males and 7 females) from 9 unrelated families. They visited hospitals for treatment of huge goiters that first appeared in childhood. Persistent growth of the thyroid gland, probably caused by thyrotropin (TSH) stimulation, partially compensated thyroid hormone production, resulting in lowered serum TSH concentrations in turn. Consequently, many patients had to undergo multiple operations. Of 11 patients who had undergone surgery, 7 had thyroid cancers. Of five patients whose thyroid tissue was available, we found a heterozygous activating mutation, either V599E or K600E, in cancerous tissue from each of 2 patients. From these observations, we conclude that goiter resulting from thyroglobulin mutations is associated with thyroid cancer.

Reporting thyroid fine-needle aspiration: Literature review and a proposal

Reporting schemes for thyroid fine-needle aspirations in the literature were reviewed and classified according to the number of categories in the scheme and the significance of each category. The sensitivity, specificity, and positive predictive and negative values were determined for each scheme, if possible. A reporting scheme based on the probability of finding carcinoma on histology is proposed.

Neural network analysis for evaluating cancer risk in thyroid nodules with an indeterminate diagnosis at aspiration cytology: identification of a low-risk subgroup

Thyroid nodules with a predominant follicular structure are often diagnosed as indeterminate at fine-needle aspiration biopsy (FNAB). We studied 453 patients with a thyroid nodule diagnosed as indeterminate at FNAB by using a feed-forward artificial neural network (ANN) analysis to integrate cytologic and clinical data, with the goal of subgrouping patients into a high-risk and in a low-risk category. Three hundred seventy-one patients were used to train the network and 82 patients were used to validate the model. The cytologic smears were blindly reviewed and classified in a high-risk and a low-risk subgroup on the basis of standard criteria. Neural network analysis subdivided the 371 lesions of the first series into a high-risk group (cancer rate of approximately 33% at histology) and a low-risk group (cancer rate of 3%). Only cytologic parameters contributed to this classification. Analysis of the receiver operating characteristic (ROC) curves demonstrated that the ANN model discriminated with higher sensitivity and specificity between benign and malignant nodules compared to standard cytologic criteria (p < 0.001). This value did not show degradation when ANN predictions were applied to the validation series of 82 nodules. In conclusion, neural network analysis of cytologic data may be a useful tool to refine the risk of cancer in patients with lesions diagnosed as indeterminate by FNAB.

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

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

Thyroid nodular lesion: analysis of cancer risk based on Kuma Hospital experience

It is a difficult question, whether it is malignant or not, when you follow up patients with thyroid nodular lesions. Cytological examination helps to solve this issue more accurately but a cancer risk still exists in patients with a negative cytology, non-diagnostic or suspicious follicular neoplasms. Analysis of cancer risk in patients with benign thyroid nodular lesions was carried out among 1044 cases who underwent thyroid surgery at Kuma Hospital, Kobe, Japan, in 2000. The purpose of this study was to provide evidence of cancer risk in those patients in Japan. Among the 356 cases with benign nodular lesions, 99 cases of papillary carcinoma were found in the thyroid parenchyma. Seventy-nine of the 99 cases were clinical cancer and were found preoperatively by cytology, while 20 out of 277 (7.22%) cases were found postoperatively as incidental carcinoma. The incidence of follicular carcinoma of a minimally invasive type in the index nodule was 22 out of 279 (7.89%) cases in patients who were surgically treated.

The value of frozen section in intraoperative surgical management of thyroid follicular carcinoma

BACKGROUND

Preoperative and intraoperative diagnosis of follicular carcinoma (FC), resulting in one-stage surgical treatment of follicular thyroid tumors, is an important issue in thyroid surgery.

METHODS

In the 10-year period there were 4158 operations performed on thyroid gland. There were 1559 patients with follicular tumors, 70 (4.4%) of them having FC. We analyzed the groups of patients with FC determined on frozen section (FS) and permanent section (PS) according to duration of clinical symptoms, ultrasound (US) examination, tumor size, patient gender and age, intensity of invasion, localization, and multiple or solitary occurrence of tumor.

RESULTS

FC was diagnosed in 39 (55.7%) patients on frozen section (FS). Among the encapsulated (minimal invasion) carcinomas, the FS was accurate in 19 of 33 (57.6%) FC and in 5 of 15 (27.8%) Hürthle cell carcinomas (HCC); among extensively invasive carcinoma in 11 of 14 (78.6%) FC and in 4 of 5 (80.0%) HCC. FC was significantly more common in men (p <.001) and in the right lobe (p <.05). We did not find statistically significant differences concerning duration of symptoms, US examination, tumor size, patient age, and multiple or solitary occurrence of the tumor between the patients with FC diagnosed on FS and the patients with FC diagnosed on PS.

CONCLUSIONS

The intraoperative diagnosis of FC is difficult. Although the percentage of false-negative results was relatively high (44.3%), there were no false-positive results. This means that the second operation was avoided in 55.7% of the patients, and no unnecessary thyroidectomies were performed. FS biopsy is an important method in surgery of follicular tumors. Improved technical support and the ability to analyze a greater number of slides will increase the accuracy of the method.

Metastasis to the thyroid gland: a case report and review of the literature

Metastatic cancer to the thyroid is uncommon. Although the thyroid is richly supplied with blood, there are a few reports of metastatic cancer spreading to this gland. The overall incidence in autopsy series has been quite varied, with rates from 1.2 to 24% of malignant tumors. Most of this metastases are not detected in clinical practice. The majority of these patients had widespread metastases and, as a result, had very short survival times. Although detection of metastases to the thyroid gland often indicates poor prognosis, aggressive surgical and medical treatment may be effective, especially for renal carcinoma. In this report, we present a case of renal carcinoma with thyroid metastases and a review of the literature.

Polymerase chain reaction in the detection of tumor cells: new approaches in diagnosis and follow-up of patients with thyroid cancer

Thyroid cancers are the most common endocrine malignancies and are being diagnosed with increasing frequency. In addition to other measures, diagnosis is based on fine-needle aspiration cytology examination. Recently, new assays using reverse transcription-polymerase chain reaction (PCR) are being tested to improve sensitivity and specificity of primary diagnosis and detection of recurrent thyroid cancer. In the preoperative diagnosis of thyroid cancer, several tissue- and/or tumor-specific mRNA have been described and in several cases, a higher sensitivity and specificity could be achieved using molecular techniques compared to conventional methods. In the postoperative follow-up of patients with thyroid cancer, conflicting data have been published and the use of PCR techniques revealed several problems of the molecular approach, which are based on some technical as well as biologic limitations. Despite these problems, which are discussed in detail in this review, molecular techniques may nevertheless improve the sensitivity and accuracy of fine-needle aspiration of thyroid nodules, fine-needle aspiration of metastases, and detection of recurrent disease in peripheral blood samples.

Can Fine-Needle Aspiration Biopsy of Thyroid Nodule Help in Determining the Extent of Surgery in Follicular and Hurthle Cell Neoplasm at a Community Teaching Institution?

Fine-needle aspiration biopsy (FNAB) was used to evaluate cold thyroid nodules in 179 patients treated between 1990 and 1998. The purpose of this study was to see whether FNAB findings of follicular or Hurthle cells could help in planning the extent of thyroid surgery. Group I patients (47) had findings suggestive of follicular or Hurthle cell neoplasm. Group II patients (132) had inconclusive results. In group I FNAB was 100 per cent correct in diagnosing follicular or Hurthle cell neoplasm with a high percentage of malignant findings (malignancy 85 per cent and benign adenoma 15 per cent). In Group II malignancy was found in 16 per cent and benign pathology in 84 per cent. Women were more likely to have malignancy than men. The average age was over 50 years in patients with either malignant or benign nodules. In addition there was no significant difference in average size of benign or malignant nodules (2.9 vs 2.6 cm respectively). When an FNAB finding was suggestive of neoplasm malignancy was found in 85 per cent. On the other hand when an FNAB was inconclusive malignancy was present in 16 per cent. Thus we conclude that using FNAB finding can guide surgical resection and recommend performing total or subtotal thyroidectomy when FNAB is suggestive of neoplasm and lobectomy when FNAB is inconclusive.

Does frozen section have a role in the intraoperative management of thyroid nodules?

BACKGROUND

Frozen section in thyroid surgery is used to make an intraoperative pathological diagnosis of malignancy in a thyroid nodule at the time of hemithyroidectomy. A positive diagnosis allows completion of thyroidectomy, thus avoiding reoperation. However, the use of fine needle aspiration cytology in making a preoperative diagnosis of cancer has resulted in the lack of a defined role for frozen section. We examined the role of frozen section as an adjunct to fine needle aspiration cytology in determining which cytological subset will benefit from frozen section.

METHODS

All patients who underwent thyroidectomy between 1992 and 2000 by a single endocrine surgeon were reviewed.

RESULTS

Two hundred and nine frozen sections were performed, of which 144 underwent preoperative fine needle aspiration cytology. Frozen sections reported 135 benign nodules, 59 follicular neoplasms, five specimens with suspicious histology and 10 cancers. Ten out of 20 thyroid cancers were correctly identified by frozen section (sensitivity: 50%; specificity: 100%), eight cancers were reported on frozen section as indeterminate and two benign. Of 144 fine needle aspiration cytological procedures, frozen section on seven suspicious aspirates identified two cancers, and frozen section on 70 follicular aspirates identified four cancers, allowing intraoperative conversions to total thyroidectomy. Frozen section on seven malignant aspirates confirmed four cancers but resulted in reoperation for three because of the indeterminate frozen section reports. There were no cancers found on 135 benign aspirates.

CONCLUSIONS

Frozen section on benign aspirates is unhelpful in the management of thyroid nodules. It need not be performed for cytologically proven malignant thyroid nodules. Selective use of frozen section complements fine needle aspiration cytology findings of suspicious or follicular lesions, especially in the subset with papillary cancer, allowing one-stage total thyroidectomy.

Influence of iodine intake on the diagnostic power of fine-needle aspiration cytology of the thyroid gland

In order to determine whether the iodine intake influences the diagnostic power of ultrasound-guided fine-needle aspiration cytology (US-FNAC), patients with nontoxic nodular goiter from an area with sufficient iodine intake (IS) (n = 938, median iodine excretion [MIE] = 103 microg/L) and from an iodine-deficient (ID) area (n = 3,601, MIE = 75 microg/L) were investigated. Elevated rates of multinodularity (59.6% vs. 49.6%, p < 0.001), nonpalpable nodules (47.6% vs. 37.3%, p < 0.001) and nondiagnostic US-FNACs (8.8% vs. 5.1%, p = 0.008), and a lower malignancy rate (1.2% vs. 2.3%, p = 0.006) were found in the ID area. Follicular tumors were encountered among positive findings. Cytohistologic comparison (ID, n = 416; IS, n = 97) revealed that the sensitivity, specificity, and diagnostic accuracy of US-FNAC were similar in the two areas (95.5% vs. 92.3%, 78.3% vs. 71.1%, 82.4% vs. 80.6%, IS vs. ID area, respectively), while a lower malignancy rate and a higher ratio of benign to malignant tumors were observed in the ID than in the IS area (10.1% vs. 22.6%, p < 0.001, and 4.38 vs. 1.50, p < 0.001, respectively). This resulted in a lower positive predictive value of US-FNAC in the ID (36/106) than in the IS area (21/36, p = 0.001), because the rate of false US-FNAC was higher in benign (67/184) than in malignant tumors (4/61, p < 0.001).

Role of fine-needle aspiration biopsy and frozen-section evaluation in the surgical management of thyroid nodules

BACKGROUND

The role of routine frozen section (FS) in the surgical management of thyroid nodules remains uncertain. This study reviewed the role of FS in the presence of an adequate fine-needle aspiration biopsy (FNAB).

METHODS

FNAB and FS were evaluated in 206 patients who had surgery for a thyroid nodule. Cytological specimens were classified as benign, malignant or suspicious. The FS diagnoses were benign, malignant or deferred.

RESULTS

A cytological diagnosis was obtained in 93 nodules; the remaining 113 were classified as suspicious, of which 21 were malignant on definitive examination. The overall accuracy of FNAB was 53 per cent. FS evaluation identified 165 lesions as benign; the diagnosis was deferred until definitive histological evaluation in only eight. The overall accuracy, therefore, was 96 per cent. Routine use of FS was cost-effective; lowering the number of reoperations led to an estimated saving of about 40 per cent.

CONCLUSION

These data suggest that FS remains an important tool in the surgical management of thyroid nodules and can reduce the number of patients requiring reoperation.

Fine needle aspiration cytology of thyroid nodules: how accurate is it and what are the causes of discrepant cases?

Fine-needle aspiration cytology (FNAC) is widely accepted as the most accurate, sensitive, specific and cost-effective diagnostic procedure in the assessment of thyroid nodules and helps to select people preoperatively for surgery. The purpose of this study was to evaluate the results of thyroid FNAC in our institution and to determine the reasons for discrepancies between the cytological and histological diagnosis. We evaluated the cytological and histological results of 254 FNACs obtained from 231 patients who underwent subsequent thyroid surgery. All of the material was blindly reviewed for quality control, by one experienced cytopathologist. All FNACs were carried out under ultrasound guidance. The cytological diagnosis was classified as benign, suspicious, malignant or unsatisfactory. The definitive histological study showed benign lesions in 195 of the 231 patients (84%). A benign diagnosis based on FNAC was correct in 105 of the 108 benign cases (97%). FNACs diagnosed as 'suspicious' resulted in a distribution of 49 benign (79%) and 13 malignant (21%) diagnoses. FNAC showed malignancy in 34 cases (13%) and in only one case did the final histology differ from cytology (correlation 97%). The percentage of FNACs that were inadequate for diagnosis was 20%. Review of cytological and histological slides did not lead to any change in the original diagnosis. Our study revealed a cytological-histological discrepancy (2%) in only 4 out of 231 cases over a period of 10 years, due to either a diagnostic or sampling error.

Efficacy of ultrasound-guided fine-needle aspiration biopsy in the diagnosis of complex thyroid nodules

Cystic thyroid nodules are considered to be one of the major causes of nondiagnostic and false-negative results on conventional fine-needle aspiration biopsy, thus limiting the potential of this method for the evaluation of complex (solid-cystic) thyroid nodules. Although ultrasound-guided fine-needle aspiration biopsy has emerged as a highly effective diagnostic method for the assessment of nonpalpable and difficult to palpate nodules, its role in complex nodules has not yet been carefully evaluated. In this study, we report the efficacy of ultrasound-guided fine-needle aspiration biopsy in 124 complex nodules in 113 patients. This method proved to be highly effective, yielding a satisfactory specimen for cytological evaluation in 94% of the nodules, suggesting that it is an excellent modality for the evaluation of complex nodules and also for the reevaluation of those nodules with a nondiagnostic result on conventional fine-needle aspiration biopsy.

Immunostaining for Met/HGF receptor may be useful to identify malignancies in thyroid lesions classified suspicious at fine-needle aspiration biopsy

The receptor for hepatocyte growth factor (Met) is not expressed in the normal thyroid but it is overexpressed in most thyroid carcinomas. We evaluated whether Met immunostaining of cytological smears from fine-needle aspiration biopsy (FNAB) may be useful for the preoperative diagnosis of thyroid cancer. Notably, routine cytological examination often fails to distinguish well-differentiated follicular carcinomas and a proportion of papillary carcinomas (low-grade papillary carcinomas and papillary carcinomas follicular variant [FVPTC]) from benign lesions: all these lesions are usually classified as suspicious. We examined 80 thyroid lesions diagnosed as suspicious at cytology that had subsequently undergone surgery. The histologic diagnosis had been: papillary carcinomas (n = 14), FVPTC (n = 11), follicular carcinomas (n = 25), atypical follicular adenomas (n = 5), follicular adenomas (n = 20), and nodular goiters (n = 5). We also studied typical papillary carcinomas (n = 30) and nodular goiters (n = 10), all correctly diagnosed at cytology. In lesions classified suspicious at routine cytology, Met immunostaining was positive in 12 of 14 (85.7%) papillary carcinomas, 8 of 11 (72.7%) FVPTC, 7 of 25 (28%) follicular carcinomas, and 5 of 5 atypical adenomas. In contrast, none of the 25 lesions cytologically suspicious but benign at histology were positive. These data suggest that Met immunostaining of suspicious cytological smears are useful for identifying malignant lesions, especially those with a papillary histotype.

Fine-needle aspiration biopsy of the thyroid

The routine use of thyroid FNAB caused profound changes in the management of thyroid nodules. FNAB allows a prompt identification and treatment of thyroid malignancies and avoids unnecessary surgery in patients with benign lesions, improving quality of life in patients with thyroid nodules. Furthermore, FNAB provides guidance for the type of surgery and reduces costs of care. On average, standard FNAB is nondiagnostic in 25% to 40% of cases, which include inadequate specimens and indeterminate (suspicious) diagnoses. In addition, a small percentage of false-negative diagnoses occur, which are unavoidable and raise concern of a late diagnosis of cancer. To minimize the limitations of FNAB, every center should reach and maintain a high standard of expertise in all of the steps of smear preparation and interpretation. Alternative modes of sampling or sample preparation may result in a reduction of nondiagnostic samples and better accuracy. Every center should set up clinical guidelines tailored to their own FNAB results and including the evaluation of clinical data. More work is needed to increase the accuracy of FNAB in suspicious cases. Toward this goal a variety of molecular markers have been evaluated; although none of them are ideal, some are promising. More studies need to be carried out in larger series to further evaluate the accuracy of these markers in identifying specific cancer histotypes within the group of suspicious lesions. It is hoped that, in the near future, the routine use of a combination of these markers will cost-effectively improve the diagnosis of malignant nodules classified as suspicious on traditional cytology. Statistical methods such as bayesian analysis or neural networks can be advantageously used to integrate different relevant information derived from family and personal history, clinical data, cytologic results, and evaluation of molecular markers.

Multiple endocrine neoplasia type iia: report of a family with a study of three generations in qatar

OBJECTIVE

To study the pattern of multiple endocrine neoplasia type IIA (MEN IIA) and describe the clinical features and results of genetic testing and treatment in 21 members of the first reported family with MEN IIA in Qatar.

METHODS

After identification of the proband, we screened all her family members (21 members) with genetic testing for the RET proto-oncogene mutation. Those subjects with the mutation were further assessed for pheochromocytoma by measurement of the 24-hour urinary vanillylmandelic acid, metanephrines, and catecholamines, and those with high levels underwent a metaiodobenzylguanidine scan and adrenalectomy. The serum calcium was measured in a effort to detect hyperparathyroidism. Those family members who had the mutation and were eligible for surgical treatment underwent total thyroidectomy and central compartment dissection. In those patients with high postoperative calcitonin levels, residual disease was sought with radiologic imaging, and follow-up was done with pentagastrin stimulation tests.

RESULTS

Of the 21 family members screened, 10 had the RET proto-oncogene mutation (codon 634, TGC->GGC) (5 females and 5 males; 6 adults and 4 children). All the adults had bilateral medullary thyroid carcinoma (MTC); four of them had lymph node metastatic lesions, and one had metastatic involvement of the liver. Two adults had pheochromocytomas. Two family members were reported to have parathyroid hyperplasia, although both were normocalcemic.

CONCLUSION

This family with MEN IIA showed classic mendelian autosomal dominant inheritance. All adult patients had MTC, two had pheochromocytomas, and two had parathyroid hyperplasia. Although one child had a high stimulated calcitonin level, the histopathologic findings were normal; another child with high stimulated calcitonin levels showed C-cell hyperplasia on histopathologic examination.

An evaluation of thallium imaging for detection of carcinoma in clinically palpable solitary, nonfunctioning thyroid nodules

OBJECTIVE

An evaluation of thallium imaging for differentiating benign from malignant lesions in clinically palpable solitary, nonfunctioning, thyroid nodules.

METHODS

Seventy-eight patients presenting with a clinically palpable solitary nonfunctioning thyroid nodule were imaged with 3 mCi thallium-201 with a pinhole acquisition at 20 minutes and 3 hours after injection. Thallium uptake was assessed as grade 1, less than the rest of the gland; grade 2, same as the rest of the gland; and grade 3, more than the rest of the gland. All patients underwent surgery and the histology was compared with the thallium scan results.

RESULTS

Of the 78 patients presenting with solitary thyroid nodule, 13 were malignant and 65 were benign. Twenty-four patients with benign disease showed no uptake of thallium at 3 hours (grade 1). Thirty-two patients with benign disease and 2 patients with malignant lesion had grade 2 uptake at 3 hours. Eleven patients with malignant disease and 9 with benign disease had grade 3 uptake at 3 hours.

CONCLUSIONS

All malignant lesions had at least grade 2 and most had grade 3 uptake at 3 hours. All lesions with grade 1 uptake at 3 hours were benign, enabling malignancy to be excluded in one-third of cases. Thallium imaging is a useful adjunct to fine-needle cytology in evaluation of solitary thyroid nodules especially when the latter is inconclusive.

Thyroid nodules: pathogenesis, diagnosis and treatment

Thyroid nodules are very frequently found and their prevalence steadily increases with age. The discovery of such lesions by high-resolution radiological imaging procedures that have been performed for other indications raises the problem of how incidentally discovered thyroid nodules should be investigated in a cost-effective manner to identify the rare patient with a clinically significant malignancy. In this review the clinical criteria that prompt the evaluation of thyroid nodules are discussed, as is the currently recommended diagnostic approach, which principally relies on fine needle aspiration biopsy. The clinical implications of the different cytological diagnoses are discussed, with a special emphasis on the management of indeterminate, microfollicular lesions. Finally, the evidence for and against suppressive thyroid hormone therapy for benign thyroid nodules and multinodular goitres is discussed, with particular consideration of high-risk patients with prior external radiation therapy to the neck region.

Role of scintigraphy with tumor-seeking agents in the diagnosis and preoperative staging of malignant thyroid nodules

The commonly used procedure for the diagnosis of thyroid nodule malignancy is based on high resolution thyroid ultrasonography (US) combined with US-guided fine needle aspiration cytology (FNAC). The other imaging procedures have a limited role in malignancy diagnosis. However, nuclear medicine procedures, particularly scintigraphy with tumor-seeking agents such as 201-thallium (201-TI), 99mTc-methoxy-isobutyl-isonitrile (99mTc-MIBI) and 99mTc-tetrofosmin may play an important role in the differential diagnosis between benign and malignant thyroid nodules in cases of non-diagnostic or inadequate FNAC. This type of scintigraphy can also be used in the follow-up of patients with cytologically 'high'-risk thyroid nodules such as Hurtle cell adenomas and follicular adenomas. Furthermore, scans with tumor-seeking agents can be helpful in determining the preoperative staging of thyroid carcinoma patients with locally advanced disease, and in accurately evaluating the extent, and consequently, the surgical management of the disease.

Sensitivity and specificity of the fine needle aspiration biopsy of the thyroid: clinical point of view

INTRODUCTION

The rates of sensitivity and specificity of fine needle aspiration biopsy (FNAB) for the diagnosis of thyroid malignancy differ considerably among various reported series. These values are influenced by three factors: (a) whether only clearly positive and negative results are considered, or whether the commonly encountered 10-20% of indeterminate/suspicious ones are included; (b) whether adenomas are considered as neoplasms in one group with carcinomas; and (c) whether only histologically proven cases are used in calculations or whether patients with benign clinical follow-up are included.

AIM

The aim of the study was to evaluate the sensitivity and specificity of FNABs performed at this institution in the last 7 years from the clinical point of view, considering only benign vs. suspicious/malignant FNAB results (indicating surgery), and benign (including adenomas) vs. malignant definitive histology.

STUDY DESIGN

Retrospective study comparing pre-operative FNAB results with definitive histological examination after operation.

PATIENTS

A total of 2492 FNABs were performed in 2100 patients (1875 women and 225 men); their ages ranged from 9 to 85 years, with a median of 46 years. Clinical diagnosis was multinodular goitre in 1330, single nodule in 591, Hashimoto's thyroiditis in 147 and subacute thyroiditis in 32 cases. In 148 instances, the nodule was cystic. A history of previous treatment for carcinoma of the thyroid was present in 12 patients. Five hundred and thirty-six patients subsequently underwent thyroid surgery.

STATISTICS

The values of sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and diagnostic accuracy were calculated.

RESULTS

The sensitivity was 86%, specificity 74%, PPV 34%, NPV 97% and diagnostic accuracy 75%.

CONCLUSIONS

The specificity and positive predictive value are low when fine needle aspiration biopsy results are divided into two categories only (these being indication for surgery or not), and when only suspicious/malignant fine needle aspiration biopsies with subsequent malignant histology are considered to be true positive. Nevertheless, the ability to discriminate 11.7% of patients with a 34% probability of malignancy (suspicious/malignant cytology) from 81.2% of patients (benign cytology) with a probability of only 3% is very helpful.

A method for guideline development: assessing practical feasibility and adaptation of thyroid nodule guidelines

The objective of this study was to assess adaptation and feasibility of practice guidelines for thyroid nodule management. For one month physicians completed a self-administered semi-structured questionnaire concerning a draft version of the guidelines for each consecutive patient. A sample group of 20 endocrinologists, 20 surgeons and 120 general practitioners from all parts of France took part in this study. The main outcome measures were whether the case description was found by the physicians, and whether recommendations were found and agreement with these recommendations were assessed. We found that two hundred and fifty-three patients (of whom 85% were women) were included in the study: 52% were seen for a surgical decision; 20% for diagnosis or screening and 28% for follow-up. Four percent of the women were pregnant; 2% of the patients had a large nodule; and 2%, a retrosternal nodule. These last three situations had not been well identified in the draft guidelines. The patient's case description was appropriately identified in 75% of the responses. Most cases reported as being not found were, however, covered by the guidelines. Physicians in private practice were less likely than the others to identify their patient's cases. Physicians agreed with the recommendation in 77% of cases. General practitioners were more likely and endocrinologists less likely than surgeons to disagree. Most disagreements and alternative proposals were not evidence-based. Our conclusion is that this study shows that the draft guidelines were applicable, and allowed minor improvements of the final version. Adapting guidelines to practice could improve their use and, consequently, the quality of health care.

Aspiration needle biopsy in preoperative selection of thyroid nodules defined at fine-needle aspiration as microfollicular lesions

The palpable thyroid nodules that are diagnosed as microfollicular by fine-needle aspiration cytologic analysis are usually excised for the low probability that the nodule is a well-differentiated follicular cancer. The authors retrospectively assess the use of aspiration needle biopsy (either 16- or 18-gauge needles) in the preoperative selection of the nodules diagnosed as microfollicular at fine-needle aspiration (either 20- or 22-gauge needles). Aspiration needle biopsy is a type of large needle biopsy that is a relatively easy and innocuous method of obtaining tissue fragments for preoperative histologic examination of palpable thyroid nodules. From 1980 through 1996, 6,314 patients with palpable thyroid nodules were examined by fine-needle aspiration; 29.5% of these nodules were also examined preoperatively by aspiration needle biopsy. Of all the patients with nodules, 6% received a fine-needle aspiration diagnosis of microfollicular nodule. Two hundred sixty of the 380 nodules (68%) that were diagnosed as microfollicular at fine-needle aspiration were also examined by aspiration needle biopsy; inadequate specimens were obtained in 17% of cases; pure microfollicular structure was confirmed by aspiration needle biopsy in 35% of the nodules; and aspiration needle biopsy showed the remaining 48% to contain a macrofollicular component suggesting a benign hyperplastic lesion. Seventeen nodules that were found to be microfollicular at fine-needle aspiration cytologic analysis and micromacrofollicular at aspiration needle biopsy were excised and the postoperative result was benign in all cases. Twenty-five nodules diagnosed as microfollicular either on both fine-needle aspiration and aspiration needle biopsy were excised and the postoperative diagnoses were benign (20 nodules) or malignant (5 nodules). These data indicate that aspiration needle biopsy can be used for preoperative selection of the nodules that are microfollicular at fine-needle aspiration by identifying the nodules with high probability of being malignant and thus contributing to the reduction in the number of surgical operations for benign nodules.

Value of re-aspirations in benign nodular thyroid disease

Fine-needle aspiration cytology (FNAC) is the most useful procedure for the evaluation of thyroid nodules. The requirement for repeated aspirations in the follow-up of benign nodular thyroid disease, however, is controversial. To determine the value of re-aspirations in benign nodular thyroid disease, we studied 457 fine-needle reaspirations performed on 216 patients (197 female, 19 male) aged 42.9+/-12 years with uninodular (n = 65) and multinodular (n = 151) thyroid disease. Two hundred fifty-seven of these were second, 137 were third, 46 were fourth, and 17 were fifth re-aspirations of the same nodule, performed in a mean follow-up time of 43.9+/-31 (3-156) months. FNAC results were benign in 407 (89%), insufficient for diagnosis in 31 (6.8%), suspicious in 16 (3.5%), and papillary carcinoma (PC) in 3 (0.7%). An initial benign diagnosis did not change after multiple aspirations in 213 (98.61%) of the cases. Three patients with initial aspirations read as benign had a diagnosis of PC from their second biopsies, (diagnosis confirmed at surgery). Re-examination of the initial FNAC revealed atypical features in 1 of the 3 patients. These 3 patients likely represent a false-negative result of the initial FNAC rather than benign nodular disease transformed to a malignant one during the follow-up period. In conclusion, a second aspiration of clinically suspicious nodules may correct a few initial false-negative results, but routine additional re-aspirations are not useful for clinically stable disease.

Pattern of thyroid lesions and role of fine needle aspiration cytology (FNA) in the management of thyroid enlargement: a retrospective study from a teaching hospital in Riyadh

The study aims to determine the cytological pattern of thyroid lesions, in addition to the utility and accuracy of fine needle aspiration (FNA) cytology as an initial diagnostic method in the investigation of these lesions among Saudi patients. Four hundred and seventy-nine (479) FNAs were performed on patients presenting with diffuse or nodular thyroid enlargement to the endocrinology clinic at King Khalid University Hospital in Riyadh during the period September 1993 to September 1996. The results of the FNA and the 125 histological diagnoses obtained from the subsequent partial and subtotal thyroidectomies were retrospectively and independently reviewed and compared by two cytopathologists. The results of the FNA cytological diagnosis showed that 372 patients (77.7%) had benign lesions, 24 (5%)) had lesions which were suspected of malignancy, 25 (5.2%) had malignant neoplasms, and 58 (12.1%) had FNAs which were inadequate for cytological assessment. Colloid and adenomatous nodules were the most common benign lesions reported (47.8%). Papillary carcinoma was the most common malignant neoplasm (4.2%). Despite the relatively limited number of patients who underwent surgery, cytohistopathology combined with statistical analysis of the results showed that our FNA accuracy rate is in the region of 94.4% with a sensitivity of 78% and a specificity of 100%. In addition, the negative predictive value (NPV) and the positive predictive value (PPV) of FNA thyroid cytology were 93% and 100% respectively. Our findings indicate that FNA cytology can be used effectively in the evaluation of both nodular and diffuse thyroid lesions whilst cytopathologist should be aware of the potential diagnostic pitfalls and the limitations of the procedure in the diagnosis of follicular, cystic, and small neoplasms, the positive identification of thyroiditis and most cases of neoplasia by itself provides justification for FNA.