Histopathologic Assessment of Capsular Invasion in Follicular Thyroid Neoplasms-an Observer Variation Study.

The assessment of capsular invasion is an essential but challenging step in the diagnosis of encapsulated follicular thyroid neoplasms. Therefore, interobserver agreement in the assessment of capsular invasion in these tumors was investigated among 11 thyroid pathologists by using virtual slides of 20 cases in which the original diagnosis considered the differential diagnosis of definite capsular invasion versus questionable capsular invasion. The assessment of capsular invasion was divided into three categories: (1) non-invasive, (2) questionable invasive, and (3) clear-cut invasive. The interobserver agreements for clear-cut invasive and non-invasive categories were fair (Kappa value = 0.578 and 0.404, respectively), whereas agreement for the questionable invasion was poor (Kappa value = 0.186). Disagreements in the assessment of invasion resulted in variable final pathological diagnoses. For example, the agreement for a diagnosis of malignancy was only fair (Kappa value = 0.545). Moreover, pathologists did not have a uniform approach for rendering a final diagnosis in cases with questionable capsular invasion, though nine of 11 pathologists did use the follicular tumor of uncertain malignant potential diagnosis as proposed by the World Health Organization classification of endocrine organs published in 2017. In conclusion, this study revealed considerable interobserver variation in the evaluation of capsular invasion, especially in follicular neoplasms with questionable invasion.

Is Vocal Cord Assessment before Total Thyroidectomy Required for All Patients?

We investigated whether laryngoscopy should be performed before total thyroidectomy on all patients without a history of neck surgery. A total of 2523 patients who underwent total thyroidectomy between January 1, 2013, and March 18, 2018, were retrospectively examined. Preoperative vocal cord examination was performed on 2070 of these patients by the otorhinolaryngology department using indirect laryngoscopy. Patients with a history of neck or thyroid surgery were not included in the study. The patients were evaluated in terms of age, gender, symptom (hoarseness/dyspnea), comorbidity, surgical history, biopsy, nodule diameter, pathological diagnosis, and tracheal deviation. Preoperative vocal cord paralysis was detected in 0.8 per cent of the patients (17/2070). Four patients (23.5%) were male and 13 patients (76.5%) were female. The mean age was 62 (range, 25-82) years. Seven of the 17 patients (41%) were symptomatic, with complaints of dyspnea in five and hoarseness in two. The univariate analysis revealed that a nodule diameter >30 mm and the presence of dyspnea were associated with vocal cord damage. Furthermore, the multivariate analysis showed that dyspnea alone was an independent variable (P = 0.011). It is recommended that preoperative vocal cord evaluation should be performed only in patients with severe symptoms, such as dyspnea.

Semiquantitative assessment of cytomorphologic features can predict mutation status of thyroid nodules with indeterminate cytologic diagnosis.

Molecular diagnostics increasingly direct the management of thyroid nodules with an indeterminate cytologic diagnosis. This study was undertaken to correlate cytomorphologic features with the molecular profiles in an effort to identify features predictive of molecular aberrations. One hundred eighty-nine thyroid nodules with an indeterminate thyroid cytology diagnosis (atypia of undetermined significance, suspicious for follicular lesion, and suspicious for malignancy) with an adequate sample submitted for targeted mutation detection by polymerase chain reaction or next-generation sequencing were assessed semiquantitatively for the following cytomorphologic parameters: cellularity, Hurthle cell changes, microfollicles, nuclear elongation, nuclear grooves, nuclear enlargement, nuclear atypia, extent of atypia, and colloid. Based on this evaluation, a cumulative cytomorphologic score (CCS) and a more simplified overall atypia score (OAS) were assigned to each case. Associations among mutational status and each of the aforementioned parameters, CCS, and OAS were determined. Of the 189 nodules with indeterminate cytology, 63 (33.3%) harbored at least 1 mutation. RAS and BRAF were the most common mutations, found in 34 (18.0%) and 13 (6.9%) cases, respectively. Both CCS and OAS were highly associated with the presence of all mutations (P < .0001) and with the presence of BRAF and RAS mutations in particular (all P < .01). Semiquantitative assessment of various cytomorphologic features in indeterminate thyroid cytology cases showed a strong association of higher OAS and CCS and incidence of BRAF and RAS mutations. Using a more objective approach to thyroid cytology can potentially decrease the overall number of indeterminate diagnoses, leading to fewer repeat procedures and unnecessary surgical procedures.

Processing the entire capsule in thyroid follicular lesions improves diagnostic accuracy.

BACKGROUND: There is contradictory evidence in literature with respect to diagnosis and management of follicular lesions of the thyroid gland. From surgical pathology stand point, pathologists require submission and processing of entire capsule for microscopic evaluation. This can be extremely challenging especially in larger lesions. METHOD: We studied the impact of submitting entire capsule on final pathologic diagnosis in cases on which only representative sections were submitted initially and entire capsule was submitted subsequently. RESULTS: A total of 80 specimens were identified. Mean size of the nodule in these cases was 4.4 ±â€¯1.9 cm. Mean initial tissue sections submitted were 11.6 ±â€¯3.6. Entire capsule was submitted subsequently in an additional 12.6 ±â€¯13.3 sections. Submission of entire capsule contributed to final diagnosis in 3 (3.8%) cases whereby foci of capsular microinvasion were identified. There was no significant difference in the requirement of subsequent sections in specimens grossed by residents compared to those grossed by pathologist assistants (10.4 ±â€¯10.8 vs. 14.4 ±â€¯14.9, p = 0.18). The processing cost of additional sections of capsule was $ 4143 in these cases. CONCLUSION: Processing of entire capsule in thyroid follicular lesions has a definitive yield that comes at a high cost. Thin slicing and looking for areas of gross abnormality such as mushrooming may be more practical especially in larger lesions.

Ultrasound Risk Assessment Combined with Molecular Markers of Galectin-3, c-MET, HBME-1 and CK19 for Diagnosis of Malignant and Benign Thyroid Nodules.

To investigate the effect of ultrasound combined with expression of Galectin-3, c-Met, HBME-1 and CK19 in differentiating malignant from benign thyroid nodules. Forty-six patients with thyroid nodules were studied with ultrasound and immunohistochemical staining of excised thyroid nodules. The data were classified and compared. The immunohistochemical staining revealed 8 benign and 41 malignant thyroid lesions. In ultrasound risk assessment, the malignancy risk was low in four nodules, medium in five and high in 37 with lymphatic metastasis in 26. A significant (P < 0.05) association existed in the expression of Galectin-3 with nodule boundary and lymphatic metastasis, in HBME-1 with nodule micro-calcification and in c-Met with nodule micro-calcification and lymphatic metastasis. CK19 expression was not significantly (P > 0.05) associated with any of ultrasound features of nodule. Galectin-3, c-Met, HBME-1 and CK19 were significantly (P < 0.05) different in malignant and benign thyroid lesions, with a significant (P < 0.01) tendency in all the molecular markers in predicting the malignant from benign lesions. The ultrasound characteristics could significantly (P < 0.001) predict malignant nodules with a significant (P < 0.05) prediction tendency. The scores of Galectin-3, c-Met and CK19 significantly (P < 0.05) increased with increase of ultrasound malignancy risk degree. In malignant and benign lesions differentiated by ultrasound, no significant (P > 0.05) difference existed in HBME-1 expression, however, with ultrasound malignancy risk increase, the score of HBME-1 expression increased significantly (P = 0.03). Galectin-3, c-Met, HBME-1 and CK19 have significantly greater expressions in thyroid malignant than benign lesions and their expression increases with increase of ultrasound malignancy risk. The combination of both ultrasound and molecular markers can be used to differentiate malignant and benign thyroid lesions.

Complementary Role of Elastography Using Carotid Artery Pulsation in the Ultrasonographic Assessment of Thyroid Nodules: A Prospective Study.

Objective: The aim of this study was to evaluate the diagnostic performance of gray-scale ultrasonography (US), Doppler scan, and elastography using carotid artery pulsation in the diagnosis of thyroid nodules and to find a complementary role of elastography. Materials and Methods: A total 197 thyroid nodules with 91 malignant and 106 benign pathologic results from 187 patients (41 males and 146 females; age range, 20-83 years; mean age, 49.4 years) were included in this prospective study. The gray-scale, Doppler US images, elastography with elasticity contrast index (ECI), and stiffness color were assessed. The diagnostic performances of each dataset were assessed in order to differentiate benign from malignant thyroid nodules. Results: The optimal cut-off value of the ECI was 1.71. The area under receiver operating characteristic curve (Az value) was 0.821 for gray-scale US, 0.661 for the ECI, 0.592 for stiffness color, and 0.539 for Doppler US. The Az value for a combined assessment of gray-scale US and the ECI was higher than that for the gray-scale US alone; however, there was no statistical difference between the two (p = 0.219). The median ECI values of follicular thyroid carcinoma (FTC) and follicular variant of papillary thyroid carcinoma (FVPTC) were significantly lower than those of the other malignant lesions (p = 0.005). Meanwhile, the diffuse sclerosing variant of PTC and a metastatic nodule showed the two highest median values of the ECI. Conclusion: For differentiating thyroid nodules, the diagnostic performances of the combination of gray-scale US and elastography with the ECI were similar to, but not superior, to those of gray-scale US alone. FVPTC and FTC have a significantly lower ECI value than those of the other malignant lesions.

Use of a low-cost telecytopathology method for remote assessment of thyroid FNAs.

BACKGROUND: Rapid on-site evaluation is a great tool for optimizing the adequacy and quality of cytologic samples. The objective of the current study was to analyze a low-cost telecytopathology method for the remote assessment of thyroid fine-needle aspiration biopsies (FNABs), with comparison of the primarily rendered adequacy and diagnosis with the final conventional analysis. METHODS: Material collected from thyroid FNABs was immediately smeared onto glass slides and stained with Diff-Quik. A conventional microscope attached to a smart device was operated on-site by either a medical student or a pathology resident for Wi-Fi transmission of the images by Skype. The cytopathologist would remotely guide the screening of the slides, zooming in and out of areas of interest. Remote assessment included an analysis of material adequacy and a preliminary diagnosis. The quality of the transmission and the number of slides also were recorded. After a washout period of 3 weeks, final diagnosis and adequacy were assigned by conventional microscopy. RESULTS: The final agreement rate for adequacy between remote and conventional analysis was 90.5%. For diagnosis, the final agreement rate was 83.3%. The diagnosis agreement rate varied, depending on the quality of transmission: there was 88% agreement when the quality was excellent, 77.8% agreement when it was good, and 62.5% agreement when it was poor. CONCLUSIONS: Low-cost telecytopathology is an efficient method for the remote assessment of thyroid FNAB adequacy and diagnosis. The wide use of such technology in low-resource or remote centers may have a positive impact on the number of adequate or satisfactory samples, optimizing the management of patients who have thyroid nodules.

Iodine deficiency a persisting problem: assessment of iodine nutrition and evaluation of thyroid nodular pathology in Portugal.

BACKGROUND: The goal of eliminating iodine deficiency (ID) by the year 2000 has still not been achieved in several countries. More than 2 billion people worldwide (over 260 million school age children) remain ID. In Europe, there are still countries, such as Portugal, without national general population data on iodine nutrition (IN). This study aims at evaluating combined complementary data of the IN of the general population through urinary iodine concentration (UIC) and the thyroid histology profile from the inland region of Beira Interior (BI), in Portugal. METHODS: UIC from a population sample of 214 volunteers (131 females and 83 males), with ages ranging from 8 to 97 years (mean 51.5 years ± SD 20.74 years), from BI was determined; the thyroid histology pattern in BI (6-year period) was evaluated; and the iodine content of the largest surface water reservoir of BI, never previously reported, was measured. RESULTS: Median UIC of 62.6 µg/L was measured. Over 92 % of the population had UIC less than 100 µg/L. From 279 histology reports evaluated, the incidence of the different types of thyroid nodular pathology in BI was established. There were 60 histologic diagnoses of malignancy. The observed ratio of papillary to follicular carcinoma relatively close to 1 and the fairly high percentage of anaplastic carcinomas are characteristic of ID areas. CONCLUSIONS: The findings of this first general population study on IN from the inland region of BI, Portugal, document significant ID. This problem, with its serious public health implications, could be corrected by having affordable iodised salt widely and generally available and by promoting a proactive population attitude generated by ample public information and educational programs as to the negative consequences of ID.

Pathological aspects of the assessment of head and neck cancers: United Kingdom National Multidisciplinary Guidelines.

This is the official guideline endorsed by the specialty associations involved in the care of head and neck cancer patients in the UK. It introduces the current best practice in histopathology and cytopathology as it pertains to head and neck and thyroid cancers. Recommendations • Accurate diagnosis of the type of malignancy is a key component of effective management. (R) • Surgeons and oncologists should understand the scope and limitations of cellular pathology in order to inform multidisciplinary discussions. (R) • A clinically suspected diagnosis of malignancy should be confirmed by biopsy or cytology before operation. (R) • Cytopathological diagnoses should be discussed with surgeons and radiologists to maximise the information gained from each modality of investigation. (R) • Pathological investigations are the basis for accurate cancer staging and stratification of clinical outcomes. (R).

Incidental thyroid nodules and thyroid cancer: considerations before determining management.

The worldwide incidence of thyroid cancer is increasing substantially, almost exclusively attributable to small papillary thyroid cancers. Increased use of diagnostic imaging is considered the most likely explanation for this reported rise, but other factors may also be contributing. The increase in health care expenditures related to managing these presumably low-risk cancers, without a clear patient benefit, has resulted in a backlash against the early detection of thyroid cancer. Currently, there is no way to confidently predict which incidentally detected thyroid nodule may be the precursor to a more aggressive process. Predictions such as these would require more accurate characterization of the biology of individual thyroid cancers than is currently possible. With time, we might prove our ability to confidently differentiate low-risk from high-risk thyroid cancers, but until that happens, routine screening for thyroid cancer by imaging billed as a "health checkup" should not be performed. However, incidentally detected thyroid nodules should be reported, and a clear medical team management plan should be developed. Our ethical responsibility is to provide patients with objective, evidence-based information about their disease status, not to assume that we know what is best for them by selectively withholding information. In addition, providing patients with psychosocial assistance will help them process the information necessary to make informed decisions that will provide them with the most value when a small thyroid nodule or cancer is incidentally identified. Herein, we summarize the epidemiological data for disease incidence, discuss some controversies in disease management, and outline the key elements and ethical considerations of informed decision making as they apply to managing incidentally detected thyroid nodules and thyroid cancer.

Atypia of undetermined significance and follicular lesions of undetermined significance: sonographic assessment for prediction of the final diagnosis.

OBJECTIVES: To determine whether radiologic assessment of thyroid nodules can potentially help guide clinical management after a cytologic diagnosis of atypia of undetermined significance or a follicular lesion of undetermined significance. METHODS: We identified 41 patients with 41 thyroid nodules initially diagnosed as atypia or follicular lesions of undetermined significance on fine-needle aspiration that were subsequently definitively diagnosed by either surgical resection or repeated fine-needle aspiration. All sonograms of nodules were reviewed by 2 blinded board-certifiedradiologists. Lesions were assessed in 3 ways: (1) Mayo pattern classification as benign, indeterminate, or worrisome for malignancy (Ultrasound Q 2005; 21:157-165); (2) thyroid imaging reporting and data system scores (scale of 1-5) based on 2 different previously published scoring criteria (Park et al [Thyroid 2009; 19:1257-1264] and Kwak et al [Radiology 2011; 260:892-899]); and (3) binary classification as benign or malignant. RESULTS: Of the 41 nodules, 25 had benign histologic findings, and 16 were malignant. Mayo pattern classification was 100% accurate for the benign score. Lesions with a Mayo score of indeterminate were malignant in 21% of cases (6 of 28) and benign in 79% (22 of 28). Lesions with a Mayo score of malignant were malignant in 91% of cases (10 of 11) and benign in 9% (1 of 11). Thyroid imaging reporting and data system scores had area under the receiver operating characteristic curve values of 0.827 for Park scores and 0.822 for Kwak scores. Radiologist binary classification of thyroid nodules showed 88% overall accuracy. CONCLUSIONS: Radiologist assessment of thyroid nodules in cases of atypia of undetermined significance or follicular lesions of undetermined significance is highly predictive of the final diagnosis and can help guide management of thyroid nodules of these pathologic types.

Imaging, genetic testing, and biomarker assessment of follicular cell-derived thyroid cancer.

Thyroid carcinoma is the most common endocrine malignancy worldwide, and its incidence continues to increase. As such the approach to a recently identified thyroid nodule is important to understand. The relevant imaging, examination, and need for fine-needle aspiration biopsy (FNA) are discussed. In approximately 25% of nodules, the diagnosis cannot be established with FNA-based cytology, and surgical excision is necessary for definitive diagnosis. Recent advances in genetic and molecular testing may increase the diagnostic accuracy of FNA in managing thyroid nodules.

Disparities in the initial presentation of differentiated thyroid cancer in a large public hospital and adjoining university teaching hospital.

BACKGROUND: Healthcare disparities associated with insurance and socioeconomic status have been well characterized for several malignancies, such as lung cancer. To assess whether there are healthcare disparities in thyroid cancer, this study evaluated the stage on initial presentation of patients with differentiated thyroid cancer (DTC) in a public versus university teaching hospital. METHODS: A retrospective chart review was performed to identify patients with a new diagnosis of DTC from January 1, 2007, to January 1, 2010, in a large public and adjoining university teaching hospital at a single academic medical center. Medical records were reviewed for demographics, pathology, and American Joint Committee on Cancer tumor-node-metastasis stage at initial presentation. RESULTS: There were 49 cases of well-DTC (96% papillary and 4% Hürthle) in the public hospital and 370 cases (95% papillary, 2% Hürthle, and 3% follicular) in the university teaching hospital. Median age (years) at presentation was 50 in the public versus 48 in the university teaching hospital (p=0.39). Ninety-six percent of public hospital patients were from ethnic minorities compared with 16% of university teaching hospital patients (p<0.0001). Only 1 (2%) public hospital patient had private insurance compared with 85% of university teaching hospital patients. Tumor status (p=0.002) and stage (p=0.03) were more advanced and extrathyroidal extension (p=0.02) was more prevalent among public hospital patients compared with university teaching hospital patients. In a multivariable analysis, public hospital, male gender, increasing age, advanced tumor status, and the presence of lymphovascular invasion were the best predictors of more advanced disease stage. Public hospital patients were 3.4 times more likely to present with advanced DTC than university teaching hospital patients of the same age, gender, tumor status, and lymphovascular invasion status (95% confidence interval 1.29-8.95). CONCLUSIONS: In a public hospital, where the patient population is defined primarily by insurance status, patients were more likely to present with advanced-stage DTC than patients presenting to an adjacent university teaching hospital. These results suggest a disparity in the stage on initial presentation of DTC, possibly resulting in a delayed diagnosis of cancer.

Intraoperative pathologic examination: cost effectiveness and clinical value in patients with cytologic diagnosis of cellular follicular thyroid lesion.

OBJECTIVE: Routine use of intraoperative pathologic examination (IOPE), including frozen section (FS) and scrape preparation cytology (SPC), during diagnostic thyroid lobectomy continues to be a source of controversy. We sought to better delineate the usefulness and cost-benefit ratio of IOPE in the context of cytologically diagnosed cellular follicular lesion (CFL) or follicular neoplasm (FN). DESIGN: Records of 205 patients who underwent thyroidectomy for cytologically diagnosed FN or CFL between 1997 and 2005 were retrospectively reviewed. IOPE results, patient demographics, and tumor characteristics were correlated to final histopathologic diagnoses. Sensitivity, specificity, predictive values, accuracy, and costs of IOPE were calculated. MAIN OUTCOME: IOPE correctly identified 3 of 16 follicular carcinomas and 9 of 36 papillary carcinomas. Sensitivity, specificity, and accuracy were 23%, 99%, and 78%, respectively. On univariate analysis, malignancy risk among follicular nodules did not correlate with age, gender, or nodule size. On multivariate analysis, nodule size was predictive of malignancy (p < 0.05). Over the entire patient series, routine IOPE resulted in a net cost savings of $74,304.33. CONCLUSIONS: IOPE reduced costs and limited the number of completion thyroidectomies necessary. IOPE is specific, cost effective, and of minimal additional risk when performed routinely for patients with CFL or FN.

[Assessment of VEGF and VEGF receptor concentrations in patients with benign and malignant thyroid tumors]. / Ocena stezen naczyniowo-sródblonkowego czynnika wzrostu (VEGF) oraz jego rozpuszczalnych receptorów (sVEGFR-1,sVEGFR-2) w surowicy krwi u chorych z lagodnymi i zlosliwymi guzami tarczycy.

Neoangiogenesis is a significant event in a cascade of growth and progression of solid tumors. Assessment of the tissue expression and measurement of the concentrations of angiogenic and antiangiogenic factors, contributing to this process, in body fluids, can be used not only for an early diagnosis of tumors and their staging but also as an important parameter of treatment efficiency evaluation. The aim of this study is to evaluate the concentrations of crucial angiogenic cytokine VEGF and its soluble receptors in peripheral blood of patients with benign and malignant thyroid tumors. The study comprised 35 patients with thyroid cancer and 10 patients with follicular neoplasm, both diagnosed by means of ultrasound-guided fine-needle aspiration biopsy. For these patients surgical treatment was instituted. The examined angiogenic factors were determined preoperatively and 4 weeks after the surgical procedures. The results were compared with the control group which comprised 10 healthy individuals. Analysing obtained results, we demonstrated high VEGF concentrations and low soluble VEGF receptor concentrations in patients with benign and malignant thyroid tumors. This fact confirms a vital role of VEGF in angiogenesis of thyroid tumors and a hypothetical antiangiogenic activity of its soluble receptors. Disequilibrium of the above-mentioned angiogenic factor concentrations is probably essential for the growth and progression of benign and malignant thyroid tumors.

[Detection of thyroid pathology during surgical exploration of the neck for primary hyperthyroidism]. / Detección de patología tiroidea durante exploración quirúrgica de cuello por hiperparatiroidismo primario.

OBJECTIVE: Our objective was to determine prevalence of incidental thyroid pathology during surgical treatment of primary hyperparathyroidism and to compare sensitivity and specificity of surgical neck exploration with histologic study of resected thyroid gland to confirm unsuspected pathologies. MATERIAL AND METHODS: This was prospective cohort study performed at the Specialty Hospital's Department of Endocrine Surgery at the Mexican Institute of Social Security's (IMSS's) Centro Médico de Occidente in Guadalajara, Jalisco State between 1995 and 2003. All were submitted to bilateral neck exploration under general anesthesia. According to the surgeon's criteria, any suspected thyroid anomaly was resected for transoperative frozen sections as well as definite histopathologic study. RESULTS: Preoperatively from a total of 44 cases of hyperparathyroidism, only four cases with thyroid anomalies were detected with neck ultrasound and/or computer tomography (CT) scan; additionally, 13 patients had thyroid anomalies found during neck exploration according to surgeon criteria. All were biopsied. Final study revealed thyroid disease in 16 cases; three had well-differentiated thyroid carcinoma and the remaining 13 patients had different benign entities. In one case, the thyroid specimen was considered normal. Sensitivity and specificity of surgeon criteria were 100 and 96%, respectively, to establish thyroid disease during neck exploration for another purpose. CONCLUSIONS: Association of hyperparathyroidism and benign and malignant thyroid disease is a common phenomenon. Independently of the ability of preoperative imaging procedures to detect unsuspected findings, we suggest exploration neck bilaterally and resection of any suspicious lesion.

The value of ultrasound-guided fine-needle aspiration cytology for thyroid nodules: an assessment of its diagnostic potential and pitfalls.

This study was conducted to assess the diagnostic potential and pitfalls of performing fine-needle aspiration cytology (FNAC) for thyroid nodules. We retrospectively analyzed 1,012 aspirated samples obtained from 806 thyroid nodules by the ultrasound (US)-guided method. Of these 806 nodules, 226 (31%) had been surgically treated, 152 (67%) of which were histologically diagnosed as malignant. The rate of sufficient aspirate was 82%, being lower in nodules with a diameter of less than 5mm (73%, P = 0.10); either calcified (77%, P = 0.043) or benign (72%, P = 0.0002). The accuracy of FNAC was 75%, the rate of indeterminate diagnosis was 16%, the false negative rate was 13%, and the positive malignancy rate was 99%. The rate of indeterminate diagnosis was higher in adenomatous goiter, follicular carcinoma, and malignant lymphoma, at P = 0.015, P = 0.0008, and P = 0.035, respectively. The accuracy was lower in follicular carcinoma and malignant lymphoma (both at P = 0.013). Sufficient aspirate was finally obtained from 701 (87%) of the 806 nodules by repeated aspiration. Of 152 malignant nodules, 28 (18%) were diagnosed after two or more aspirations, and the accuracy was improved to 81% by repeating the procedure. These findings indicated that repeated aspiration may be a simple and effective method of improving the diagnostic potential of FNAC.

Total thyroidectomy or thyroid lobectomy in patients with low-risk differentiated thyroid cancer: surgical decision analysis of a controversy using a mathematical model.

There is a general consensus that total or near-total thyroidectomy is the optimal treatment for patients with high risk differentiated thyroid cancer (DTC), but the optimal extent of thyroidectomy in patients with low risk DTC continues to be controversial. To determine the optimal extent of thyroidectomy in patients with low risk DTC, we used decision analysis to compare the trade-offs of total thyroidectomy (TT) to thyroid lobectomy (TL). The decision analysis model included the probabilities of thyroidectomy complications, risk of DTC recurrence, and death from DTC. This information was obtained from the literature and from outcome data for patients with low risk DTC from our institution. In addition, the concept of utilities was used in the analysis. To determine the utility of each health outcome state (thyroidectomy complication, DTC recurrence, and DTC mortality for low risk patients) a survey was conducted. Overall, prospective patients viewed DTC recurrence as less desirable than thyroidectomy complication. The utilities assigned by the survey participants varied over a wide range, with 61.5% of the individuals viewing the occurrence of a thyroidectomy complication as better than DTC recurrence. At baseline utilities and probabilities, TT had a higher expected utility than TL. One-way sensitivity analysis varying the rates of (1) thyroidectomy complication, (2) DTC recurrence, and (3) DTC mortality over the possible range showed that complication from initial thyroidectomy was the most important factor that determined the preferred extent of thyroidectomy. TL was the preferred surgical approach only if a complication rate of > 33:1, TT/TL complication rate ratio, was assumed. When no differences in DTC recurrence between the two approaches was assumed in the model, TL had a higher expected utility using the baseline utilities of thyroidectomy complication and DTC mortality. The analysis indicates that TT in patients with low risk DTC is preferable to TL. However, TL is preferred if (1) no difference in the DTC recurrence rate between the two approaches is assumed, (2) a higher complication rate for TT is used (> 33 times higher), or (3) the utility ratio of thyroidectomy complication to DTC recurrence is < 0.8 TL. We believe this decision analysis model provides an objective approach that others can use to select the optimal extent of thyroidectomy based on patient preference of health outcome states, institution-specific outcome data for DTC recurrence or mortality, and the surgeon-specific complication rate.