INCIDENTAL THYROID NODULES: RACE/ETHNICITY DISPARITIES AND OUTCOMES.

OBJECTIVE: Black patients have a significantly lower incidence of well-differentiated thyroid cancer (WDTC) compared to all other race/ethnic groups, while white patients appear to be at greater risk. This study examines incidental thyroid nodules (ITNs) to assess whether racial disparities in WDTC arise from a differential discovery of ITNs-perhaps due to socioeconomic disparities-or reflect true differences in thyroid cancer rates. METHODS: A retrospective review was performed of all patients who underwent fine-needle aspiration (FNA) of thyroid nodules by our academic medical center's endocrinology division between January 2006 and December 2010. Medical records were reviewed to identify whether the biopsied thyroid nodule was discovered incidentally through nonthyroid-related imaging or identified by palpation. RESULTS: FNAs were performed on 1,369 total thyroid nodules in 1,141 study patients; 547 (48%) were classified as white, and 593 (52%) were classified as nonwhite. Among this cohort, 36.6% of patients underwent biopsy for an ITN. White patients were 1.6 times more likely to have undergone a biopsy for a nodule that was incidentally identified compared to nonwhites ( P<.0001). Indicators of socioeconomic status (SES) did not have a significant association with ITNs. Within the ITN cohort, 4.9% of nonwhite patients were found to have a thyroid malignancy compared to 12.9% of white patients ( P<.01). CONCLUSION: The higher incidence of thyroid cancer in white patients appears to be not only due to diagnostic bias, but also to a true difference in cancer prevalence. ABBREVIATIONS: FNA = fine-needle aspiration; ITN = incidental thyroid nodule; SEER = Surveillance Epidemiology and End Results; SES = socioeconomic status; WDTC = well-differentiated thyroid cancer.

Retrospective Analysis of Thyroid Nodules: Thyroid Cancer Risk Factors in Suzhou, China.

BACKGROUND: Thyroid nodules are common, frequently discovered in clinical practice and the incidence has increased in recent decades. They are clinically important primarily due to their malignant potential, because 2 to 5% are malignant. Correct identification of the malignancy in thyroid nodules is a diagnostic challenge, leading to potentially unnecessary surgery in patients for whom final histology is benign. Because there is no accurate preoperative detection, it is very important to predict the risk of malignancy in patients with nodular thyroid disease. METHODS: The medical records of 405 patients who underwent surgery for nodular thyroid disease were retrospectively reviewed. Then clinical parameters and preoperative serum markers were compared between benign thyroid nodular disease and thyroid cancer groups. RESULTS: Younger than 40 years (OR 2.14, 95% CI 1.02 - 4.47, p = 0.044), preoperative TSH levels equal to or higher than 1.79 mIU/L (OR 1.76, 95% CI 1.05 - 2.95, p = 0.033), TgAb positivity (OR 2.59 95% CI 1.25 - 5.37, p = 0.01) and nodules less than or equal to 1 cm (OR 5.51, 95% CI 2.61 - 11.66, p < 0.001) were associated with increased risk of thyroid cancer in patients with thyroid nodules. CONCLUSIONS: The retrospective analysis suggests that younger patients with nodular thyroid disease cannot ignore the small size nodules, especially those with higher TSH levels and TgAb positivity.

Comparative histopathological analysis of sporadic pediatric papillary thyroid carcinoma from Japan and Ukraine.

This study set out to compare structural and invasive characteristics of sporadic papillary thyroid carcinoma (PTC) in age-matched groups of children and adolescents of Japan and Ukraine to provide detailed histopathological analysis of tumors from different geographical areas with different iodine intake. A total of 348 (160 Japanese and 188 Ukrainian) PTCs from patients without radiation history were analyzed initially as a combined pediatric group and then subdivided into childhood (aged ≤14 years) and adolescent (aged from 15 to ≤18 years) age series. On multivariate comparison, the Japanese pediatric PTC was characterized by a higher sex ratio (p=1.504E-4), and a higher frequency of microcarcinoma (p=0.039), papillary dominant growth pattern (p=0.024), focal oxyphilic cell metaplasia (p=7.644E-6), intrathyroid spread (p=0.010), lymphatic/vascular invasion (p=0.01) and regional lymph node metastases (p=3.540E-6). In the Ukrainian group, multifocal (p=0.004) and non-encapsulated tumors with the solid-trabecular growth pattern (p=0.05) were more frequent. Childhood Japanese PTCs differed from Ukrainian PTCs by more pronounced invasive properties such as lymphatic/vascular invasion and nodal disease, but did not differ by the dominant growth pattern. In adolescents, the differences were detected not only for lymph node metastases, but also for a higher frequency of the papillary dominant pattern in Japanese PTC. Overall, significantly higher frequencies of oxyphilic cell metaplasia and more pronounced invasive features observed in the Japanese PTC in both age-matched series represent the major differences between the tumors from two geographical areas.

Anatomical variations of the recurrent laryngeal nerve in Chinese patients: a prospective study of 2,404 patients.

The recurrent laryngeal nerve (RLN) shows some anatomical variations that can potentially compromise the safety of thyroid surgery. The purpose of this prospective study was to identify the anatomical variations of the RLN in Chinese patients undergoing thyroid surgery. Between January 2007 and December 2013, 2,404 Chinese patients were hospitalized for thyroid surgery with dissecting of the RLN unilaterally or bilaterally. The patients consisted of 510 men and 1,894 women, with a median age of 45.0 years. Overall 3,275 RLNs, including 1,576 left- and 1,699 right-side nerves, were dissected. The anatomical variations were identified in 690 RLNs, including 305 left- and 385 right-side nerves. We identified as many as seven RLN anatomical variations in Chinese patients. These findings indicate that anatomical variations of the RLN are common, and the identification of these anatomical variations of the RLN can help to minimize the risk of post-operative RLN paralysis.

Fine needle aspiration of thyroid nodules in the pediatric population: a 12-year cyto-histological correlation experience at North Shore-Long Island Jewish Health System.

BACKGROUND: Diagnostic evaluation of thyroid nodules by FNA is used in the clinical management triage based on the knowledge of the rate of malignancy of each diagnostic category. The Bethesda System for Reporting Thyroid Cytopathology was published in 2007 by the National Cancer Institute (NCI). Using this classification, we studied our institution's experience in the pediatric population calculating the rate of malignancy for each diagnostic category, comparing our findings to our general patient population and that of the literature. METHODS: 13,312 thyroid FNAs were performed at our institution between 1998 and 2010. 282 cases were from patients under 19 years of age. We reviewed and reclassified these cases using the new NCI categories, and pursued cytology-surgical follow-up. RESULTS: Of the 282 FNA cases, 20.92% (59) were classified as unsatisfactory (U), 48.22, % (136) benign (B), 2.12% (6) Atypia of undetermined significance (AUS), 14.18% (40) suspicious for follicular neoplasm (FN), 2.12% (6) suspicious for malignancy (SM) and 12.41% (35) positive for malignancy (P). The U-category was further classified into nondiagnostic (ND) 12.41% (35) and cysts (C) 8.51% (24). Seventy-four children had surgical follow-up. The rates of histologically confirmed malignancy were 10% in U (1/10), 0% in B (0/17), 50% in AUS (2/4), 39% in FN (7/18), 100% in SM (4/4) and 100% in P (24/24) categories respectively. Among the U category, malignancy rate was 0% for the ND category and 25% for the C category. CONCLUSIONS: To our knowledge, this is the first study to apply the NCI categories to the pediatric population. The rate of malignancy in the U category was only seen in the specimens with cystic component. AUS and FN categories had a higher malignancy rate (50 and 39% respectively) as compared with that of the general population (15 and 30% respectively). Given that the rates of malignancy are higher for cysts and AUS, the literature recommendation to "follow-up and repeat" may not apply to the pediatric population. Surgery may be reasonable in these categories instead.

The prevalence of thyroid nodules and its relationship with metabolic parameters in a Chinese community-based population aged over 40 years.

To investigate the prevalence of thyroid nodules (TN) among a community population aged >40 years and to explore the association between TN and its metabolic risk factors. Data from 9,533 adults aged over 40 years who participated in the epidemiological investigation of thyroid nodules in a Chinese community-based population from June to December 2011 were included in the analyses. We compared the levels of metabolic indices between the TN group and healthy controls. The prevalence of TN was 46.6% (39.7%, men; 50.3%, women) and it increased significantly with increasing age (P < 0.001). It was significantly higher in the group with hypertension than in that with normotension (P < 0.001) and was 43.0% in the normal blood glucose group, 49.4% in the prediabetes group, and 50.9% in the diabetes group (P < 0.001). Logistic regression analysis indicated that hypertension [odds ratio (OR) = 1.121 (1.025-1.225)] as well as prediabetes and diabetes [OR = 1.130 (1.036-1.233)] were all independent risk factors for TN after adjustment for sex, age, body mass index, blood lipid levels, smoking status, and alcohol consumption. The elderly population had a high prevalence of TN. Hypertension as well as prediabetes and diabetes might be independent risk factors for TN.

Detection of BRAFV600E mutation on fine needle aspiration specimens of thyroid nodule refines cyto-pathology diagnosis, especially in BRAF600E mutation-prevalent area.

BACKGROUND: Between 10 and 30% of the fine needle aspiration biopsies (FNABs) of thyroid nodules are diagnosed as 'indeterminate'. A molecular diagnostic method is needed to reduce unnecessary surgery in this group. In Korea, most thyroid cancer is the classic papillary type and the BRAF(V600E) mutation is highly prevalent. AIM: To evaluate the role of pre-operative detection of BRAF(V600E) mutation in the FNAB specimens of thyroid nodules in a BRAF(V600E) mutation-prevalent geographical area. PATIENTS AND METHODS: In 137 specimens of FNAB (107 papillary thyroid carcinomas (PTC); 3 follicular thyroid carcinomas (FTC); 2 undifferentiated thyroid carcinomas; 25 benign lesions), both direct DNA sequencing and PCR-RFLP were used for detecting the BRAF(V600E) mutation. The sensitivity and specificity were calculated. We analysed the association between BRAF(V600E) mutation and the clinico-pathological parameters. RESULTS: The BRAF(V600E) mutation was present in 93 (83%) of 112 thyroid cancers. Direct DNA sequencing showed a sensitivity of 83.0% and a specificity of 96.0%. The sensitivity and specificity of PCR-RFLP were 78.6% and 80.0%, respectively. Among 25 cases with indeterminate FNAB cytology, 8 patients had malignant lesions (5 PTC and 3 FTC). Three (60%) of 5 PTCs and 1 out of 17 benign lesions had BRAF(V600E) mutation (only one false positive case and the definitive pathology showed atypical nodular hyperplasia that could be a premalignant lesion). The diagnostic accuracy of this molecular method in only the 25 indeterminate nodules was 76% (19/25). No mutation was found in 3 FTCs. Among 107 PTCs, there was no significant association of the BRAF(V600E) mutation with the known risk factors. CONCLUSION: Detection of the BRAF(V600E) mutation in FNAB specimens refines the FNAB-cytology diagnosis, especially in a BRAF(V600E) mutation-prevalent area. Direct DNA sequencing was a more reliable method than PCR-RFLP for detecting the BRAF(V600E) mutation with a high sensitivity and specificity.

Risk of malignancy in Filipinos with thyroid nodules--a matched pair analysis.

BACKGROUND: Ethnicity is an infrequently cited risk factor for thyroid cancer. This study aims to determine whether patients of Filipino origin assessed at a tertiary referral center are at increased risk of thyroid cancer and to quantify that risk. METHODS: This is a retrospective analysis of 72 Filipino patients with thyroid nodules undergoing thyroidectomy individually matched to 72 controls according to demographics, risk factors, and pre-referral investigations. RESULTS: Thyroid cancer was found in 50 (69.4%) Filipino patients compared with 28 (38.9%) controls. Odds ratio for malignancy in Filipinos was 3.57 (95% confidence interval, 1.79-7.12). Pathologic characteristics of thyroid cancer were not significantly different in the two groups. The median follow-up for Filipino patients was 14.1 months (range, 1.4 months-19.7 years). Recurrence occurred in four Filipino patients, and one patient with anaplastic thyroid cancer died of the disease. CONCLUSIONS: Filipino patients with thyroid nodules are at significantly increased risk of thyroid cancer compared with matched controls, and hence the index of suspicion for malignancy should be high when evaluating these patients.