Sonographic Features of Atypical and Initially Missed Parathyroid Adenomas: Lessons Learned From a Single-Center Cohort.

CONTEXT: Awareness of typical and atypical ultrasonographic (US) features of parathyroid adenomas (PAs) is crucial since US is the most widely used first-line imaging modality. OBJECTIVE: The purpose of this study was to describe the atypical features of PAs on US and other possible factors leading to a false negative examination in a large single-center cohort. MATERIALS AND METHODS: The US records of 457 PAs in 445 patients with biochemically proven primary hyperparathyroidism (PHPT) were evaluated in a prospectively maintained database. Atypical size, composition, shape, echogenicity, location, and vascular pattern on US were noted. For patients who previously had at least one negative US examination in referring centers, the main possible reason was defined accordingly. RESULTS: The study group included 359 female and 86 male patients with PHPT. Typical sonographic features were observed in 231 PAs (51%), whereas 226 (49%) had at least one atypical US feature. The most common atypical features were atypical size (29%), followed by atypical echogenicity (19%), shape (8%), location (7%), and composition (7%), respectively. There were 122 initially missed PAs in all groups. The most frequent main atypical US features leading to false negative examinations were atypical size (22.1%) and atypical location (18.8%). Inexperience was third most common reason (16.3%) for false negative US examinations. CONCLUSIONS: Almost half of PAs have at least one atypical feature on US. Awareness of the high prevalence of atypical US features could increase the accuracy of US examination and potentially decrease demand for more expensive second-line imaging modalities.

The sonographer's and pathologist's perspective of echogenic microfoci in papillary thyroid carcinoma.

Objective: Punctate echogenic foci (PEF)/microcalcifications are thought to represent psammoma bodies (PB) in histopathology. However, there are few and contradictory data on this. Different types of sonographic echogenic microfoci (EMF) are seen in papillary thyroid carcinoma (PTC), and their histopathological equivalents are not clearly known. There is also conflicting data on the interobserver agreement between the sonographers on EMF. Methods: We prospectively collected US video records of PTC nodules with and without EMF in two large thyroid centers. All video recordings were independently interpreted by three blinded, experienced sonographers. EMF were classified as true microcalcifications (punctate echogenic foci (PEF) ≤1 mm long), linear microechogenities (>1 mm long, posterior acoustic enhancement of the back wall of a microcystic area), comet-tail artifacts/reverberations or linear microechogenities with comet-tail artifacts/reverberations, non-shadowing coarse echogenic foci (>1 mm nonlinear areas) and unclassifiable. Histopathological evaluation was performed by two blinded, qualified pathologists. Results: A total of 114 malignant nodules were included. The average Cohen's kappa (κ) of three sonographers for the EMF presence was 0.775, indicating substantial agreement. A substantial agreement for PEF with 0.658 κ, only fair agreement for other types of EMF with 0.052 to 0.296 κ were detected. EMF were significantly associated with PB and papillae. PEF had an evident relationship with PB in multivariate analysis. There was a strong positive correlation between the amount of PEF and PB (r = 0.634, P < 0.001). Conclusions: PEF in PTC mainly correspond to PB on histopathology. Although observation of EMF varies among sonographers, this inconsistency can be reduced by classifying EMF into subgroups and keeping the term 'PEF' only for true microcalcifications.

Radioguided occult lesion localization for minimally-invasive parathyroidectomy without quick PTH monitoring and frozen section: impact of the learning curve.

OBJECTIVES: Minimally-invasive parathyroidectomy (MIP) is a surgical procedure that reduces the duration of operation, hospital costs, and hypocalcemia, and shortens the length of hospital stay. This study addressed the important procedural details of the radioguided occult lesion localization (ROLL)-MIP technique and evaluated the consequences of the learning curve from a series of patients. PATIENTS AND METHODS: A total of 80 patients who underwent ROLL-MIP for a single parathyroid adenoma were included into this retrospective study. In order to analyze the effect of the learning curve, these subjects were then divided into 2 groups per time period and the operative times were compared. Group A consisted of 22 previously reported patients who served as the control group. Group B consisted of 58 consecutive patients. RESULTS: Serum calcium and parathyroid hormone (PTH) levels were normalized in all of the patients within 2 days and remained normal during the follow-up period (31 ± 18.5 months). None of the patients who underwent ROLL-guided parathyroidectomy suffered temporary or permanent recurrent laryngeal nerve injuries. Mean operation time (time from incision to excision of the adenoma) was 23 ± 6 min in Group A and 18 ± 7 min in Group B. Mean operative times were significantly shorter in group B. CONCLUSION: The success of MIP administered with the ROLL technique in a single adenomatous patient was quite high. This method seems especially valuable in patients with atypically located or small adenomas.

Thyroid Nodules Are More Prevalent in Subjects with Colon Polyps, Independent of Insulin Resistance.

OBJECTIVE: Colorectal polyps and thyroid nodules are common disorders linked to hyperinsulinemia and metabolic syndrome (Mets). The direct association between these two diseases is not clear. We aimed to analyze the prevalence of thyroid nodules in subjects with and without colorectal polyps. The secondary aim was to establish the prevalence of Mets and its parameters in both disorders and to determine if insulin resistance and hyperinsulinemia are common underlying pathophysiological mechanisms. SUBJECTS AND METHODS: One hundred and five subjects with colorectal polyps (71 males, 34 females) and 68 controls (28 males, 40 females) were enrolled. The parameters of Mets together with TSH, insulin, low-density lipoprotein cholesterol, and homeostasis model for assessment of insulin resistance levels were calculated. We performed thyroid ultrasonography in all participants. RESULTS: The prevalence of Mets was similar in the colorectal polyp and control groups (37.1 vs. 37.3%, p = 0.982). The prevalence of Mets was nonsignificantly higher in subjects with a documented thyroid nodule compared to subjects without a thyroid nodule (43.0 vs. 32.6%, p = 0.205). The prevalence of thyroid nodules in subjects with colorectal polyps was significantly higher than in subjects without polyps (52.9 vs. 35.3%, p = 0.017). Compared to subjects with no colorectal polyps, we established a significant increase in the odds of having thyroid nodules (OR 2.05; 95% CI: 1.097-3.860, p = 0.017). The presence of colorectal polyps and age in the adjusted model were established to be independent risk factors for having thyroid nodules (p = 0.025 and p = 0.007, respectively). CONCLUSION: These results may support the presence of other common mechanisms in the development of these two pathologies other than insulin resistance and hyperinsulinemia.

Distribution of RET Mutations and Evaluation of Treatment Approaches in Hereditary Medullary Thyroid Carcinoma in Turkey.

OBJECTIVE: This retrospective multicenter study, centrally conducted and supported by the Society of Endocrinology and Metabolism of Turkey, aimed to evaluate the impact of free RET proto-oncogene testing in medullary thyroid carcinoma (MTC) patients. Surgical timing, adequacy of the treatment, and frequency of prophylactic thyroidectomy (PTx) in mutation carriers were also assessed. METHODS: Genetic testing for MTC and pheochromocytoma was conducted between July 2008 and January 2012 in 512 patients. Application forms and RET mutation analyses of these patients whose blood samples were sent from various centers around Turkey were assessed retrospectively. An evaluation form was sent to the physicians of the eligible 319 patients who had confirmed sporadic MTC, familial MTC (FMTC), multiple endocrine neoplasia type 2 (MEN2), or who were mutation carriers. Physicians were asked to give information about the surgical history, latest calcitonin levels, morbidity, mortality, genetic screening, and PTx among family members. Twenty-five centers responded by filling in the forms of 192 patients. RESULTS: Among the 319 patients, RET mutation was detected in 71 (22.3%). Cys634Arg mutation was the most prevalent mutation (43.7%), followed by Val804Met in 18 patients (25.4%), and Cys634Tyr in 6 patients (8.5%). Among 192 MTC patients, the diagnosis was sporadic MTC in 146 (76.4%), FMTC in 14 (7.3%), MEN2A in 15 patients (7.9%), and MEN2B in one patient. The number of mutation carriers among 154 apparently sporadic MTC patients was 8 (5.2%). Ten patients were submitted to PTx out of twenty-four mutation carriers at a mean age of 35±19 years. CONCLUSION: Turkish people have a similar RET proto-oncogene mutation distribution when compared to other Mediterranean countries. Despite free RET gene testing, the number of the PTx in Turkey is limited and relatively late in the life span of the carriers. This is mainly due to patient and family incompliance and incomplete family counselling.

Metformin Decreases Thyroid Volume and Nodule Size in Subjects with Insulin Resistance: A Preliminary Study.

OBJECTIVE: The aim of this study was to investigate the effects of metformin on thyroid volume and nodule size. SUBJECTS AND METHODS: Prospective data were gathered on 100 newly diagnosed subjects with insulin resistance (68 female, 32 male) between August 2008 and May 2010. Each subject followed a standard diet and exercise program, and received 1,700 mg/day of metformin therapy for 6 months. The height, weight, waist circumference (WC) and thyroid hormone levels of each subject were measured. Additionally, the dimensions of the thyroid lobes and maximum diameter of each thyroid nodule were determined by ultrasonography. BMI and thyroid volumes were also calculated. Insulin resistance was estimated by homeostasis model assessment. All these parameters were measured at the beginning and at the end of the treatment period. RESULTS: BMI and WC decreased significantly after metformin therapy (34.5 ± 5.1 vs. 32.7 ± 4.8, p < 0.0001, and 106.3 ± 11.8 vs. 101.8 ± 19.0 cm, p = 0.008, respectively). Insulin resistance also decreased after metformin therapy (4.5 ± 1.9 vs. 2.9 ± 1.7, p < 0.0001). The mean thyroid volume (22.5 ± 11.2 vs. 20.3 ± 10.4 ml, p < 0.0001) and mean thyroid nodule size (12.9 ± 7.6 vs. 11.7 ± 7.2 mm, p < 0.0001) also decreased after treatment. CONCLUSION: In subjects with insulin resistance, metformin therapy significantly decreased thyroid volume and nodule size.

Thyroid volume in patients with glucose metabolism disorders.

OBJECTIVE: Thyroid volume and the prevalence of thyroid nodules are higher in patients with insulin resistance. A relationship between thyroid volume and glucose metabolism disorders (GMD) has not as yet been clarified. The present retrospective study aimed to investigate the association between GMD and thyroid volume. SUBJECTS AND METHODS: We investigated the data of 2,630 patients who were evaluated for thyroid biopsy in our hospital. The study population included 602 patients with GMD, 554 patients with diabetes mellitus (DM) and 1,474 patients with normal glucose metabolism as a control group. We obtained the levels of serum thyroid stimulating hormone (TSH) and the thyroid volumes of those patients retrospectively. RESULTS: The median ages for the control group, GMD group and DM group were 55 (15-91) years, 60 (27-97) years, and 65 (27-91) years respectively and there was a statistically significant difference between the groups with regard to age and gender (p<0.001). Levels of TSH were similar in all groups. The median total thyroid volumes for patients with DM and GMD were significantly higher than that of the control group [22.5 (3-202) mL, 20.2 (4-190) mL, and 19.2 (3-168) mL respectively, p≤0.001 for all parameters]. Also the median total thyroid volume for patients with DM was significantly higher than that of the GMD group (p<0.001). According to the correlation analysis, thyroid volume was significantly correlated with age (r=0.92, p<0.001) and TSH (r=0.435, p<0.001). Age, gender, TSH levels, GMD and DM diagnosis were independently correlated with thyroid volume. CONCLUSION: The thyroid gland is one of the target tissues of metabolic disorders. We reported a positive correlation between GMD/type 2 DM and thyroid volume. Further controlled, prospective, randomized studies on this subject are required to gain more information.

Thyroid volume in patients with glucose metabolism disorders / Volume da tiroide em pacientes com alterações do metabolismo da glicose

Objective Thyroid volume and the prevalence of thyroid nodules are higher in patients with insulin resistance. A relationship between thyroid volume and glucose metabolism disorders (GMD) has not as yet been clarified. The present retrospective study aimed to investigate the association between GMD and thyroid volume. Subjects and methods: We investigated the data of 2,630 patients who were evaluated for thyroid biopsy in our hospital. The study population included 602 patients with GMD, 554 patients with diabetes mellitus (DM) and 1,474 patients with normal glucose metabolism as a control group. We obtained the levels of serum thyroid stimulating hormone (TSH) and the thyroid volumes of those patients retrospectively. Results The median ages for the control group, GMD group and DM group were 55 (15‐91) years, 60 (27‐97) years, and 65 (27‐91) years respectively and there was a statistically significant difference between the groups with regard to age and gender (p<0.001). Levels of TSH were similar in all groups. The median total thyroid volumes for patients with DM and GMD were significantly higher than that of the control group [22.5 (3‐202) mL, 20.2 (4‐190) mL, and 19.2 (3‐168) mL respectively, p≤0.001 for all parameters]. Also the median total thyroid volume for patients with DM was significantly higher than that of the GMD group (p<0.001). According to the correlation analysis, thyroid volume was significantly correlated with age (r=0.92, p<0.001) and TSH (r=0.435, p<0.001). Age, gender, TSH levels, GMD and DM diagnosis were independently correlated with thyroid volume. Conclusion The thyroid gland is one of the target tissues of metabolic disorders. We reported a positive correlation between GMD/type 2 DM and thyroid volume. Further controlled, prospective, randomized studies on this subject are required to gain more information. .

Objetivo O volume da tiroide e a prevalência de nódulos tiroidianos são mais altos em pacientes com resistência à insulina. A relação entre o volume da tiroide e os transtornos do metabolismo da glicose (TMG) ainda não foi elucidada. O objetivo do presente estudo retrospectivo foi investigar a associação entre os TMG e o volume da tiroide. Sujeitos e métodos: Analisamos os dados de 2.630 pacientes que foram avaliados para biópsia de tiroide em nosso hospital. A população estudada incluiu 602 pacientes com TMG, 554 pacientes com diabetes melito (DM) e 1.474 pacientes com metabolismo normal da glicose, como grupo controle. As concentrações de hormônio tireoestimulante (TSH) e os volumes da tiroide para esses pacientes foram obtidos de forma retrospectiva. Resultados As idades medianas para o grupo controle, grupo TMG e grupo DM foram 55 (15‐91), 60 (27‐97) e 65 (27‐91) anos, respectivamente, e houve diferença estatisticamente significativa entre os grupos com relação à idade e ao gênero (p<0,001). Os níveis de TSH foram similares em todos os grupos. A mediana do volume total da tiroide para pacientes com DM e TMG foi significativamente maior do que para os pacientes do grupo controle [22,5 (3‐202) mL, 20,2 (4‐190) mL, e 19,2 (3‐168) mL, respectivamente, p≤0,001 para todos os parâmetros]. Além disso, a mediana do volume total da tiroide para pacientes com DM foi significativamente maior do que no grupo TMG (p<0,001). De acordo com a análise de correlação, o volume da tiroide foi significativamente correlacionado com a idade (r=0,92; p<0,001) e TSH (r=0,435; p<0,001). A idade, o gênero, a concentração de TSH e o diagnóstico de TMG e DM se correlacionaram com o volume da tiroide de forma independente. Conclusão A tiroide ...

Radioguided occult lesion localization for minimally invasive parathyroidectomy: technical consideration and feasibility.

PURPOSE OF THE REPORT: Minimally invasive parathyroidectomy (MIP) constitutes one of the main surgical approaches for the patient with primary hyperparathyroidism (PHPT) caused by a single parathyroid adenoma. The purpose of the study was to investigate the feasibility of radioguided occult lesion localization (ROLL) for MIP and the potential effects of the method in histopathologic evaluation. MATERIALS AND METHODS: Twenty-two patients, diagnosed with PHPT biochemically and candidates for surgery, underwent ROLL-guided MIP (ROLL-MIP). Parathyroid adenomas were searched for and identified with the guidance of an intraoperative gamma probe. The final diagnosis was confirmed by histopathologic analysis. All specimens were analyzed for the presence of parenchymal hemorrhage, congestion, neutrophil leukocyte infiltration, necrosis, cystic degeneration, subcapsular hematoma, subcapsular fibrin/neutrophil leukocyte infiltration, and disarray of the fibrous capsule of adenoma. RESULTS: All injected lesions were effectively located over the skin with very high count rates depending on the injected activity and location of the lesion. Serum calcium and parathyroid hormone (PTH) levels normalized in all patients and stayed within the normal range during the follow-up period. None of the patients who underwent ROLL-MIP suffered temporary or permanent recurrent laryngeal nerve injuries. The mean operative time was 23 ± 7 min. Parenchymal hemorrhage, congestion, subcapsular hematoma, and fibrin/neutrophil leukocyte infiltration were common histopathologic features. CONCLUSION: The use of ROLL-MIP in patients with PHPT due to a single parathyroid adenoma in the neck is technically safe and effective. It is more valuable in scintigraphy-negative patients when parathyroid adenoma is either demonstrated on ultrasonography by typical findings or confirmed by PTH washout. The ROLL-MIP technique does not impair the postoperative histopathologic examination of the parathyroid glands.

The relationship between thyroid volume and malignant thyroid disease.

The present retrospective study aimed to investigate the relationship between thyroid volume and prevalence of thyroid cancer. We investigated the data of 3,850 patients who underwent fine-needle aspiration biopsy (FNAB). Biopsy results were evaluated as diagnostic or nondiagnostic, and diagnostic results were classified as benign, malignant, and indeterminate. We included 2,672 patients who underwent FNAB firstly in our hospital and evaluated as diagnostic biopsy except subgroup of indeterminate. We obtained cytologic data, levels of serum thyroid-stimulating hormone (TSH), and thyroid volumes of those patients retrospectively. Among 2,672 patients with thyroid nodule, 2,562 (95.9 %) patients had benign cytology and 110 (%4,1) patients had malignant cytology. There was no correlation between the malignancy and gender (p = 0.935), and patients with malignant cytology were younger (52 vs 59, p < 0.001). Also, TSH levels were higher in patients with malignant than benign cytology (p = 0.017). Median volume of right part, left part, and total thyroid for patients who had malignant cytology was significantly lower than patients who had benign cytology (8.3, 7.1, 15.9 vs 10.8 ml, 9.0 mml, 20.6 ml, respectively, p ≤ 0.001 for all parameters). The results demonstrated that thyroid cancer prevalence was higher in patients with low thyroid volume. According to our results, thyroid volume should be considered as a risk factor for malignancy in the evaluation of thyroid nodules.

Impaired glucose metabolism is a risk factor for increased thyroid volume and nodule prevalence in a mild-to-moderate iodine deficient area.

OBJECTIVE: Insulin resistance (IR) is a key factor involved in the pathogenesis of impaired glucose metabolism. IR is associated with increased thyroid volume and nodule prevalence in patients with metabolic syndrome. Data on the association of thyroid morphology and abnormal glucose metabolism are limited. This prospective study was carried out to evaluate thyroid volume and nodule prevalence in patients with pre-diabetes and type 2 diabetes mellitus (DM) in a mild-to-moderate iodine deficient area. MATERIALS AND METHODS: Data were gathered on all newly diagnosed patients with pre-diabetes and type 2 diabetes mellitus between May 2008 and February 2010. 156 patients with pre-diabetes and 123 patients with type 2 DM were randomly matched for age, gender, and smoking habits with 114 subjects with normal glucose metabolism. Serum thyroid-stimulating hormone (TSH) and thyroid ultrasonography was performed in all participants. RESULTS: Mean TSH level in the diabetes group (1.9±0.9 mIU/L) was higher than in the control group (1.4±0.8 mIU/L) and the pre-diabetes group (1.5±0.8 mIU/L) (P<0.0001 for both). Mean thyroid volume was higher in the pre-diabetes (18.2±9.2mL) and diabetes (20.0±8.2mL) groups than in controls (11.4±3.8mL) (P<0.0001 for both). Percentage of patients with thyroid nodules was also higher in the pre-diabetes (51.3%) and diabetes groups (61.8%) than in controls (23.7%) (P<0.0001 for both). CONCLUSIONS: The results suggest that patients with impaired glucose metabolism have significantly increased thyroid volume and nodule prevalence.

Medullary thyroid carcinoma in a patient with Hashimoto's thyroiditis diagnosed by calcitonin washout from a thyroid nodule.

Serum calcitonin is a tumor marker used in the diagnosis and follow-up of medullary thyroid carcinoma. Calcitonin washout evaluation is a new method used for suspicious thyroid nodules and lymph nodes. Limited clinical data are present about the efficacy of this method. A 61-year-old female patient with known Hashimoto's thyroditis and an 8-mm hypoechoic nodule was presented with one previously benign fine-needle aspiration cytology (FNAC). On referral to our department, she had a moderately high-serum calcitonin level, and we repeated the FNAC that was reported as nondiagnostic. We performed FNAC for the third time together with calcitonin washout evaluation from the thyroid nodule. The FNAC was again nondiagnostic, but the calcitonin washout level from the thyroid nodule was 152.569 pg/mL. Total thyroidectomy was performed, and the diagnosis was confirmed as medullary thyroid carcinoma. Calcitonin washout evaluation may be a useful method in the differential diagnosis of patients with thyroid nodules having moderately high-serum calcitonin levels.

The relationship between glucose metabolism disorders and malignant thyroid disease.

BACKGROUND: Previous studies have shown a positive relationship between insulin resistance and several common adult cancers. The present retrospective study aimed to investigate the association between glucose metabolism disorders (GMDs) and the prevalence of thyroid cancer. METHODS: We investigated the data of 4272 patients who had undergone fine-needle aspiration biopsy (FNAB) of thyroid nodules. The biopsy results were evaluated as diagnostic or non-diagnostic and the diagnostic results were classified as benign, malignant, and indeterminate. In this study, we included 2234 of the above patients who had undergone FNAB at our hospital and whose biopsy results were evaluated as diagnostic and were classified as either benign or malignant. We obtained the cytologic data and the glucose metabolism status of these patients retrospectively. RESULTS: Of the 2234 patients, 629 (28.1 %) had GMD (impaired fasting glucose, impaired glucose tolerance). Malignant cytology was determined in 106 (4.7 %) patients overall. Of the 629 patients with GMD, 582 (92.5 %) patients had benign cytology and 47 (7.5 %) patients had malignant cytology. Fifty-nine (3.7 %) of the 1605 normoglycemic patients had malignant cytology. Malignant cytology was determined more frequently in the patients who had GMDs (p < 0.001). CONCLUSION: The results demonstrated that thyroid cancer prevalence was higher in patients with GMD. According to our results, GMD should be considered as a risk factor for malignancy in the evaluation of thyroid nodules.

Metabolic syndrome is associated with increased risk of acute exacerbation of COPD: a preliminary study.

Studies have confirmed correlation between metabolic syndrome (MetS) and chronic obstructive pulmonary disease (COPD). However, to date, no studies have analyzed correlation between exacerbations of COPD (ECOPD) and MetS. The aim of this preliminary study was to examine if presence of MetS increases the frequency and duration of ECOPD. Patients with COPD were prospectively enrolled and followed between March 2008 and September 2009. Medical records, pulmonary function tests, chest X-rays; laboratory test results were gathered to establish the presence of COPD and MetS. Patients were divided in two groups; with and without MetS. The ECOPD was defined as worsening of symptoms requiring increased use of rescue medications and/or need for either systemic steroids or antibiotics or that led to emergency room visit or hospitalizations during 12 months follow-up. A total of 106 patients were recruited, 29 with MetS and 77 without. The mean exacerbation of COPD frequency was 2.4 ± 0.8 in MetS group versus 0.68 ± 0.6 in the control group during the follow-up period (P < 0.001). Mean duration of each exacerbation was 7.5 ± 1.5 days in patients with MetS versus 5 ± 2.4 days in patients without. Serum C-reactive protein (r = 0.31, P = 0.001), fasting blood glucose (r = 0.55, P < 0.001), and triglycerides (r = 0.251, P = 0.01) were positively and significantly correlated with exacerbation frequency. This study demonstrates an association between ECOPD and its duration with the MetS. The systemic inflammation induced by common cytokines may explain the linkage between the two conditions.

Fine-needle aspiration biopsy of thyroid nodules: comparison of diagnostic performance of experienced and inexperienced physicians.

OBJECTIVE: To determine whether a difference exists in terms of obtaining adequate cytologic samples from ultrasound-guided fine-needle aspiration cytology (US-FNAC) between experienced and inexperienced physicians in a tertiary referral center. METHODS: In a prospective design, all patients with thyroid nodules of at least 10 mm in diameter were referred for US-FNAC tissue sampling as a part of their diagnostic work-up. Between May 2006 and September 2009, 997 euthyroid patients with 1,320 thyroid nodules were referred for US-FNAC by the attending endocrinologist (experienced physician) or 1 of 2 endocrinology fellows (inexperienced physicians). RESULTS: Of the 1,320 nodules, 713 biopsy specimens were obtained by the experienced physician and 607 were obtained by the inexperienced physicians. Nodule size was significantly larger in the endocrinologist's group of patients than in the fellows' group of patients (17 mm versus 14 mm, respectively; P<.001). The inadequacy rate of the US-FNAC procedures performed by the experienced physician (22 of 713 thyroid nodules or 3.1%) was significantly lower than for those performed by the inexperienced physicians (102 of 607 thyroid nodules or 16.8%) (P<.001). CONCLUSION: We conclude that, with increasing operator experience, the number of inadequate cytologic specimens generated by US-FNAC procedures is substantially reduced. This limits both direct and indirect costs and also minimizes the risks of possibly unnecessary surgical procedures.

Hashimoto's thyroiditis is not associated with increased risk of thyroid cancer in patients with thyroid nodules: a single-center prospective study.

BACKGROUND: The risk of thyroid carcinoma in patients with thyroid nodules associated with Hashimoto's thyroiditis (HT) is a debatable issue. The studies defining the true risk of thyroid malignancy are scanty and mainly depend on retrospective series. To eliminate inherent bias of retrospective studies, this prospective study was carried out to evaluate the true malignancy rate of unselected thyroid nodules in patients with HT who underwent fine-needle aspiration cytology (FNAC). METHODS: These prospective data were gathered on all patients newly diagnosed with thyroid nodules who were sent for FNAC between May 2006 and August 2009. All patients were evaluated for the presence of HT diagnosis by measuring thyroid autoantibodies. If a patient had at least one positive thyroid autoantibody, then the patient was defined as HT with thyroid nodules. There were 164 patients (147 women and 17 men) with thyroid nodules associated with HT (HT group). There were 551 patients (432 women and 119 men) with thyroid nodules without HT (control group). All patients underwent FNAC and ultrasonography (US). RESULTS: The malignancy rate was 1.0% in HT group (2 out of 191 nodules) and 2.7% in the control group (19 out of 713 nodules), a not significant (p = 0.19) difference. In the two cytologically malignant nodules in HT group and 19 in the control group, papillary thyroid carcinoma was diagnosed after thyroidectomy and histopathological examination. US features of nodule echogenicity, structure, margin, and Doppler flow were similar between the two groups. US features of microcalcification and absence of peripheral halo were more prominent in the nodules of the control group (p = 0.002 and p < 0.001, respectively). CONCLUSIONS: On the basis of cytopathological criteria, thyroid nodules in patients with HT are no more likely to be malignant than in those without HT. Many of the US features of benign thyroid nodules are similar in patients with and patients without HT.

Rising thyroid cancer incidence in the world might be related to insulin resistance.

Studies have reported an increasing incidence of thyroid cancer worldwide. The reasons are likely related to improved imaging modalities, altered histopathologic criteria for diagnosis of thyroid cancer, and nuclear exposure. However, the classical assumption derived from epidemiological studies is that it should be questioned whether there are other modifiable risk factors contributing to this increased incidence. Insulin resistance (IR), which is a major component of metabolic syndrome (MetS), is associated with cardiovascular disease risk. Furthermore, previous studies have shown a positive relationship between IR and several common adult cancers. Incidence of thyroid cancer is increasing in parallel to the rise of MetS (and thus IR) incidence. In recent reports, patients with IR have larger thyroid volumes and higher risk for formation of thyroid nodules. Additionally, it was also shown that increased prevalence of IR is present in patients with differentiated thyroid carcinoma. It can be hypothesized that a relationship between the IR and thyroid cancer could be one reason for increasing incidence in the world.

Metabolic syndrome and its components are associated with increased thyroid volume and nodule prevalence in a mild-to-moderate iodine-deficient area.

OBJECTIVE: Metabolic syndrome (MetS) is a cluster of metabolic abnormalities with insulin resistance (IR) as a major component. It has been recently questioned whether MetS and its related components are associated with functional and morphological alterations of the thyroid gland. The aim of our study is to examine thyroid volume and nodule prevalence in a case-control study of patients with MetS in a mild-to-moderate iodine-deficient area. DESIGN: Two hundred and seventy-eight patients with MetS were randomly matched for age, gender, and smoking habits with 261 subjects without MetS. Serum TSH, free tri-iodothyronine and thyroxine, and the level of IR, which was estimated by the homeostasis model assessment for IR, as well as other MetS parameters were evaluated. Thyroid ultrasonography was performed in all subjects. All subjects with thyroid nodules >1 cm were offered to undergo thyroid fine needle aspiration biopsy. RESULTS: TSH was significantly positively correlated with the presence of MetS diagnosis. There was no association between free thyroid hormone levels and MetS and its related components. Mean thyroid volume was significantly higher in patients with MetS than in controls (17.5 + or - 5.5 vs 12.2 + or - 4.2 ml, P<0.0001). Also the percentage of patients with thyroid nodules was significantly higher in patients with MetS (50.4 vs 14.6%, P<0.0001). Subjects were also divided into two groups according to the presence of IR. The group of subjects with IR had increased thyroid volume and nodule formation. The odds ratio for the development of thyroid nodule in the presence of IR was 3.2. TSH as well as all MetS components were found to be independent predictors for thyroid volume increase. IR but not TSH was found to be correlated with thyroid nodule formation. Thyroid cancer was diagnosed in 3 out of 38 patients with MetS who agreed to have a biopsy (7.9%). None of the subjects in the control group was diagnosed to have thyroid cancer. CONCLUSIONS: The results suggest that patients with MetS have significantly increased thyroid volume and nodule prevalence. Multivariate regression analysis model demonstrated that the presence of IR contributed substantially to this increased risk. Our data provide the first evidence that IR is an independent risk factor for nodule formation in an iodine-deficient environment.