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BACKGROUND Incidentally found thyroid tumor (thyroid incidentaloma, TI) on F-18 fluorodeoxyglucose (FDG) positron emission tomography-computed tomography (PET-CT) is reported in 2.5%-5% of patients being investigated for non-thyroid purposes. Up to 50% of these cases have been diagnosed to be malignant by cytological/histological results. Ultrasonography (US) and fine-needle aspiration cytology are recommended for thyroid nodules with high FDG uptake (hypermetabolism) that are 1 cm or greater in size. It is important to accurately determine whether a suspicious hypermetabolic TI is malignant or benign. AIM To distinguish malignant hypermetabolic TIs from benign disease by analyzing F-18 FDG PET-CT parameters and to identify a cut-off value. METHODS Totally, 12761 images of patients who underwent F-18 FDG PET-CT for non-thyroid purposes at our hospital between January 2016 and December 2020 were retrospectively reviewed, and 339 patients [185 men (mean age: 68 ± 11.2) and 154 women (mean age: 63 ± 15.0)] were found to have abnormal, either focal or diffuse, thyroid FDG uptake. After a thorough review of their medical records, US, and cytological/histological reports, 46 eligible patients with focal hypermetabolic TI were included in this study. The TIs were categorized as malignant and benign according to the cytological/histological reports, and four PET parameters [standardized uptake value (SUV)max, SUVpeak, SUVmean, and metabolic tumor volume (MTV)] were measured on FDG PET-CT. Total lesion glycolysis (TLG) was calculated by multiplying the SUVmean by MTV. Both parametric and non-parametric methods were used to compare the five parameters between malignant and benign lesions. Receiver operating characteristic (ROC) curve analysis was performed to identify a cut-off value. RESULTS Each of the 46 patients [12 men (26.1%; mean age: 62 ± 13.1 years) and 34 women (73.9%; mean age: 60 ± 12.0 years)] with focal hypermetabolic TIs had one focal hypermetabolic TI. Among them, 26 (56.5%) were malignant and 20 (43.5%) were benign. SUVmax, SUVpeak, SUVmean, and TLG were all higher in malignant lesions than benign ones, but the difference was statistically significant (P = 0.012) only for SUVmax. There was a positive linear correlation (r = 0.339) between SUVmax and the diagnosis of malignancy. ROC curve analysis for SUVmax revealed an area under the curve of 0.702 (P < 0.05, 95% confidence interval: 0.550-0.855) and SUVmax cut-off of 8.5 with a sensitivity of 0.615 and a specificity of 0.789. CONCLUSION More than half of focal hypermetabolic TIs on F-18 FDG PET-CT were revealed as malignant lesions, and SUVmax was the best parameter for discriminating between malignant and benign disease. Unexpected focal hypermetabolic TIs with the SUVmax above the cut-off value of 8.5 may have a greater than 70% chance of malignancy; therefore, further active assessment is required.

Background/aim Thyroid cancer is the most common type of endocrine cancer and its incidence and mortality are increasing. However, few studies on the molecular factors related to its poor prognosis have been performed. The aim of our study was to identify a poor prognostic factor for thyroid cancer to reduce its overtreatment, recurrence, and mortality. Materials and methods The present study is a retrospective study of 55 patients who were diagnosed with papillary thyroid cancer and operated in Korea from September 2013 to November 2015. Results Mts1 is a member of the S100 protein family and is involved in tumor progression and metastasis. Mts1 was highly expressed in patients with thyroid cancer and high Mts1 levels were related to poor prognoses such as lymph node metastasis. Conclusion Mts1 is associated with aggressive pathological features in thyroid cancer, and may be a poor prognostic factor for thyroid cancer.

BACKGROUND Post-thyroidectomy hypoparathyroidism may result in various transient or permanent symptoms, ranging from tingling sensation to severe breathing difficulties. Its incidence varies among surgeons and institutions, making it difficult to determine its actual incidence and associated factors. OBJECTIVE This study attempted to estimate the incidence of post-operative hypoparathyroidism in patients at two tertiary institutions that share a common data model, the Observational Health Data Sciences and Informatics. METHODS This study used the Common Data Model to extract explicitly specified encoding and relationships among concepts using standardized vocabularies. The EDI-codes of various thyroid disorders and thyroid operations were extracted from two separate tertiary hospitals between January 2013 and December 2018. Patients were grouped into no evidence of/transient/permanent hypoparathyroidism groups to analyze the likelihood of hypoparathyroidism occurrence related to operation types and diagnosis RESULTS Of the 4848 eligible patients at the two institutions who underwent thyroidectomy, 1370 (28.26%) experienced transient hypoparathyroidism and 251 (5.18%) experienced persistent hypoparathyroidism. Univariate logistic regression analysis predicted that, relative to total bilateral thyroidectomy, radical tumor resection was associated with a 48% greater likelihood of transient hypoparathyroidism and a 102% greater likelihood of persistent hypoparathyroidism. Moreover, multivariate logistic analysis found that radical tumor resection was associated with a 50% greater likelihood of transient hypoparathyroidism and a 97% greater likelihood of persistent hypoparathyroidism than total bilateral thyroidectomy. CONCLUSIONS These findings, by integrating and analyzing two databases, suggest that this analysis could be expanded to include other large databases that share the same Observational Health Data Sciences and Informatics protocol.

Post-thyroidectomy hypoparathyroidism may result in various transient or permanent symptoms, ranging from tingling sensation to severe breathing difficulties. Its incidence varies among surgeons and institutions, making it difficult to determine its actual incidence and associated factors. This study attempted to estimate the incidence of post-operative hypoparathyroidism in patients at two tertiary institutions that share a common data model, the Observational Health Data Sciences and Informatics. This study used the Common Data Model to extract explicitly specified encoding and relationships among concepts using standardized vocabularies. The EDI-codes of various thyroid disorders and thyroid operations were extracted from two separate tertiary hospitals between January 2013 and December 2018. Patients were grouped into no evidence of/transient/permanent hypoparathyroidism groups to analyze the likelihood of hypoparathyroidism occurrence related to operation types and diagnosis. Of the 4848 eligible patients at the two institutions who underwent thyroidectomy, 1370 (28.26%) experienced transient hypoparathyroidism and 251 (5.18%) experienced persistent hypoparathyroidism. Univariate logistic regression analysis predicted that, relative to total bilateral thyroidectomy, radical tumor resection was associated with a 48% greater likelihood of transient hypoparathyroidism and a 102% greater likelihood of persistent hypoparathyroidism. Moreover, multivariate logistic analysis found that radical tumor resection was associated with a 50% greater likelihood of transient hypoparathyroidism and a 97% greater likelihood of persistent hypoparathyroidism than total bilateral thyroidectomy. These findings, by integrating and analyzing two databases, suggest that this analysis could be expanded to include other large databases that share the same Observational Health Data Sciences and Informatics protocol.

Background: Postoperative hypoparathyroidism is a major complication of thyroidectomy that occurs when the parathyroid glands are inadvertently damaged during surgery. Although intraoperative images are rarely used to train AI because of its complex nature, our group recognized the potential of training AI to intraoperatively detect parathyroid glands using various augmentation methods. The aim of the present study was to train an effective artificial intelligence (AI) model to detect parathyroid glands during thyroidectomy and evaluate its accuracy. Methods: Video clips of the parathyroid gland were collected during thyroid lobectomy procedures. Confirmed parathyroid images were used to form three types of datasets according to augmentation status: baseline, geometric transformation, and generative adversarial network-based image inpainting. The average precision was set as the primary outcome regarding the performance of parathyroid detection performance. Findings: The performance of the AI model in detecting parathyroid glands based on baseline data was 77%. This performance was enhanced by applying both geometric transformation and image inpainting augmentation methods. Between the two, the geometric transformation data augmentation dataset demonstrated superior results compared to that of the image inpainting model. The average precision was 79% in the transformation dataset vs. 78.6% in the inpainting dataset. However, when the model was subjected to images of a completely different thyroidectomy approach, image inpainting methods proved to be more effective compared to both geometric transformation and baseline (46% vs. 37% vs. 33%). Conclusions: Our study demonstrated the utility of our AI model, which, when aided with appropriate augmentation methods, is potentially an effective and generalizable tool for intraoperative identification of parathyroid glands during thyroidectomy. Furthermore, this technology has significant potential to be easily extended to identifying important structures during other surgical procedures in general. Funding Information: Basic Science Research Program of the National Research Foundation of Korea [NRF-2019R1C1C1008384]. Declaration of Interests: We declare no competing interests. Ethics Approval Statement: Institutional review board approval was acquired (GDIRB2019-359), and research was conducted in accordance with the Declaration of Helsinki in its latest form.

In order to analyze the associations between thyroid cancer and environmental factors, we analyzed the national sample cohort representative of the entire population provided by the Korean National Health Insurance Service database record from 2006 to 2015. The cohort was categorized according to age, body mass index, income, residential areas, frequency of exercise, frequency of alcohol drinking, diet, presence or absence of hyperthyroidism, presence or absence of hypothyroidism, and smoking data. Age ≥ 55 years (HR 0.68, 95% CI 0.53–0.88), lower income (0.57, 0.40–0.80), and current smoking (0.69, 0.55–0.85) were associated with lower thyroid cancer occurrence among men. Body mass index (BMI) ≥ 25 kg/m2 (1.51, 1.26–1.82), higher income (1.44, 1.19–1.76), urban residence (1.24, 1.03–1.49), and presence of hypothyroidism (3.31, 2.38–4.61) or hyperthyroidism (2.46, 1.75–3.46) were associated with higher thyroid cancer occurrence among men. Age ≥ 55 years (0.63, 0.56–0.71), moderate alcohol drinking (0.87, 0.77–0.99), and current smoking (0.56, 0.37–0.85) were associated with lower thyroid cancer occurrence among women. BMI ≥ 25 kg/m2 (1.41, 1.26–1.57), frequent exercise (1.21, 1.07–1.36), higher income (1.18, 1.06–1.32), urban residence (1.17, 1.06–1.29), and presence of hypothyroidism (1.60, 1.40–1.82) or hyperthyroidism (1.38, 1.19–1.61) were associated with higher thyroid cancer occurrence among women. In conclusion, age ≥ 55 years and current smoking were associated with lower thyroid cancer occurrence, while BMI ≥ 25 kg/m2, higher income, urban residence, hypothyroidism, and hyperthyroidism were associated with higher occurrence in both men and women.

BACKGROUND Studies effectively examining temporal patterns of papillary thyroid cancer (PTC) recurrence are currently lacking. The purpose of this study was to examine sites of PTC recurrence, interval from initial treatment to recurrence, and changing patterns of recurrence during long-term follow-up. METHODS Records of 134 patients with PTC recurrence were analyzed retrospectively. RESULTS The most common site of initial recurrence was the lateral neck. In 6.7% of patients, distant metastases occurred as initial recurrences. In 74%, recurrences occurred within the first 5 years of surgery, whereas in 5.2%, and 1.5%, recurrences occurred between 10 to 20 years and after 20 years of surgery, respectively. Mean time to recurrence and distant metastasis was 48.2 months and 92.5 months, respectively. Male sex (p = .002), size (p < .001), N classification (p < .001), and recurrence frequency (p = .049) were prognostic factors for distant recurrence. CONCLUSION Men with PTC tumors larger than 2 cm, lateral neck node metastasis, and multiple local recurrences should be scrutinized for distant metastasis even after 10 years. © 2017 Wiley Periodicals, Inc. Head Neck 39: 767-771, 2017.

BACKGROUND Papillary thyroid microcarcinomas (PTMCs) often demonstrate lateral lymph node (LN) metastasis. The purpose of this study was to assess whether the size of primary tumor should be considered in deciding lateral neck dissection extent. METHODS We conducted a retrospective comparison of patients with PTMC and papillary thyroid carcinoma (PTC) larger than 1 cm who received lateral LN dissection from 2009 to 2015. RESULTS PTMC group had more frequent metachronous metastasis, multifocality, less involvement of lower third thyroid, lower metastatic central LN counts and ratio, and lower metastatic total LN ratio. The two groups showed no difference in lateral LN metastatic pattern. Male and lymphovascular invasion were more often found in PTMCs with synchronous lateral LN metastatic events than metachronous presentations. CONCLUSIONS Relying on the size of the tumor to determine lateral neck dissection extent could be unreliable, because there is no observed difference in lateral neck metastatic count and pattern between PTC and PTMCs.

Purpose: Invasive treatments have increased the risks of iatrogenic vascular injuries in neonates. Acute complications, such as thrombosis, rupture and pseudoaneurysm, require accurate diagnosis and prompt correction. In arteriovenous fistulas (AVFs) identified in time, some resolve spontaneously whereas others progress and cause major problems; potential growth disturbances and limb discrepancies. The paper is to evaluate the timing of surgery based on considerations of operation risk and expected clinical course in AVF neonates.Methods: We reviewed the charts of 2776 neonates admitted to the neonatal intensive care unit of the Department of Pediatrics of GMC over the 7-year period (Jan 2010-2017).Results: Eight (4 males, 4 females) had vascular lesions (0.29%). Mean gestational age was 196.4 days (range, 179-218 days), mean birth weight 985 g (range, 690-1340 g), mean gestational age at operation 352 days (range, 95-679 days), mean weight at operation 1825 g (range, 1230-2700 g), and mean time between diagnosis of fistula and operation 308 days (range, 41-646 days). Definite limb size discrepancy on simple radiographs was identified in 3 patients operated upon more than 1 year after being diagnosed with AVF. In 2 neonates aged between 6 months and 1 year, leg edema was evident and resolved postoperatively. In 3 neonates with simultaneous fistulas in both thighs, surgical correction was preferred for ipsilateral lesions with intense bruit on auscultation. Contralateral small fistulas resolved spontaneously in these 3 neonates within 6 months of initial AVF diagnosis.Conclusion: Early surgery should not be considered mandatory in all AVF neonates, based on considerations of long-term sequelae, the potential for iatrogenic injury to normal vascular structures and the wide-spectrum of clinical courses. Modulation of operative timing within the 6 months following diagnosis is reasonable as it does not increase risks of permanent impairment or sequela and can avoid unnecessary surgery.

Delphian lymph node (DLN) metastasis has long been considered a prognostic marker of head and neck malignancy. These days, the significance of DLN in thyroid cancer has come to the fore. The objective of the present study was to evaluate the clinical significance of DLN metastasis in patients with papillary thyroid cancer (PTC).The study was carried out between July 2009 and December 2011, and DLN was detected in 245 of 898 PTC patients who underwent total thyroidectomy and bilateral central compartment neck dissection. In those 245 patients DLN status was correlated with clinical and pathologic factors, including age, gender, tumor size, extrathyroidal extension (ETE), lymphovascular invasion (LVI), and central and lateral nodal metastasis.DLN metastasis was found in 20 % of the patients studied (49 of 245), and DLN metastasis was correlated with tumor size, multicentricity, bilaterality, and LVI excluding ETE (all p0.05). The proportion of male patients was higher in the DLN metastasis positive group than in the DLN metastasis negative group (34.7 vs. 13.3 %; p0.05). Most of the patients (95.9 %) with DLN metastasis had other central neck node metastasis, and the metastatic central lymph node ratio was higher (0.38 ± 0.23 versus 0.09 ± 0.16; p0.001) and lateral neck node metastasis was more common (2.6 vs. 32.7 %0.001) than in patients without DLN metastasis. For central and lateral compartment nodal metastasis, DLN status had sensitivity, specificity, positive and negative predictive values of 100, 37.4, 58.1, and 100 %, and 85.3, 76.2, 97.4, and 32.7 %, respectively. Multivariate analysis showed that the factors affecting DLN involvement were tumor size and LVI. Patients with positive DLN were ~1.6 times more likely to have further central compartment disease and 3.6 times more likely to have lateral compartment disease.DLN metastasis in patients with PTC is related to a number of poor prognostic factors. Furthermore DLN involvement implies that the patients are predicted to have heavy burden of central neck node metastasis and are more likely to have further lateral neck node metastasis. It is recommended that DLN is evaluated and dissected in all patients with thyroid cancer. If DLN metastasis is suspected, the surgeon should thoroughly dissect the central neck compartment and pay particular attention to the lateral lymph node compartments.

Studies effectively examining temporal patterns of papillary thyroid cancer (PTC) recurrence are currently lacking. The purpose of this study was to examine sites of PTC recurrence, interval from initial treatment to recurrence, and changing patterns of recurrence during long-term follow-up.Records of 134 patients with PTC recurrence were analyzed retrospectively.The most common site of initial recurrence was the lateral neck. In 6.7% of patients, distant metastases occurred as initial recurrences. In 74%, recurrences occurred within the first 5 years of surgery, whereas in 5.2%, and 1.5%, recurrences occurred between 10 to 20 years and after 20 years of surgery, respectively. Mean time to recurrence and distant metastasis was 48.2 months and 92.5 months, respectively. Male sex (p = .002), size (p.001), N classification (p.001), and recurrence frequency (p = .049) were prognostic factors for distant recurrence.Men with PTC tumors larger than 2 cm, lateral neck node metastasis, and multiple local recurrences should be scrutinized for distant metastasis even after 10 years. © 2017 Wiley Periodicals, Inc. Head Neck 39: 767-771, 2017.

Obesity appears to be related to papillary thyroid carcinoma (PTC) in the observational studies, although its relationship concerning the PTC prognosis has not been established. We investigated the association between body mass index (BMI) and the prognosis of PTC.The WHO BMI classification was used to stratify the degree of obesity. The final outcome was disease status, including recurrence and persistence, of 783 PTC patients. We reviewed patients' BMI, disease status, and other prognostic factors retrospectively.The mean BMI was 24.2 kg/mThere was no significant difference in the prognosis according to BMI in PTC patients. However, old age, male gender, and advanced T-stage patients were found more frequently in the higher BMI group than in the lower BMI group.

Various techniques for endoscopic thyroidectomy have been introduced in the past decade, and the cosmetic superiority of these techniques has been universally acknowledged. We developed the endoscopic thyroidectomy via bilateral axillo-breast approach (BABA) and have performed more than 500 operations. The aims of this study are to analyze the surgical outcomes and to evaluate the effectiveness and safety of BABA endoscopic thyroidectomy. Between February 2004 and March 2008, 512 patients with thyroid diseases underwent BABA endoscopic thyroidectomy. The criteria analyzed were clinicopathologic characteristics, types of operation, operation time, tumor–node–metastasis (TNM) stage on the basis of the 7th edition of the American Joint Committee on Cancer (AJCC), results after radioactive ablation therapy, and recurrence of disease in these patients. Of 512 patients, 397 had a malignant tumor and 115 had benign thyroid disease. Eight patients were diagnosed with Graves’ disease, and nine patients underwent completion thyroidectomy. Three cases were subjected to open thyroidectomy due to uncontrolled bleeding. Mean operation time was 151.2 ± 38.1 min for total and near-total thyroidectomy, and 141.7 ± 50.1 min for subtotal thyroidectomy and lobectomy. Regarding postoperative complications, transient hypocalcemia occurred in 31.1% of patients and permanent hypoparathyroidism occurred in 4.2% of patients. Transient hoarseness occurred in 20.3% of patients, and permanent vocal cord palsy occurred in 1.7%. Mean hospital stay after operation was 3.34 ± 0.8 days (range 3–7 days), and mean follow-up period was 57.1 ± 17.6 months (range 38.5–71.7 months). There were eight cases of recurrent thyroid carcinoma, and no mortality has occurred up to the present time. Endoscopic thyroidectomy via bilateral axillo-breast approach is a safe and effective method that gives good surgical completeness, a low rate of postoperative complications and recurrence, and an excellent cosmetic result. Therefore, this method is a good choice for patients with surgical thyroid diseases.

Anaplastic thyroid carcinoma (ATC) is the most aggressive type of thyroid carcinoma. The purpose of this study was to evaluate the combined cytotoxic effects of paclitaxel and lovastatin in ATC cell lines.ATC cells were treated with paclitaxel and lovastatin, separately or together, and the cytotoxicity of the compounds was determined by quantifying cell viability and apoptosis. We conducted an isobologram analysis to investigate the combined effect of the two drugs.In 8505C cells, cellular viability was inhibited by lovastatin and paclitaxel in a concentration-dependent manner (p = 0.002 and p = 0.020, respectively). The IC(50) of lovastatin was 3.53 μM and that of paclitaxel was 5.98 nM. In BHT-101 cells, cellular viability was also inhibited in a concentration-dependent manner by lovastatin and paclitaxel (p = 0.020 and p = 0.032, respectively). The IC(50) of lovastatin was 17.13 μM and that of paclitaxel was 35.26 nM. In 8505C cells, paclitaxel and lovastatin alone induced apoptosis in a concentration-dependent manner. However, both an isobologram analysis on inhibition of viability and an analysis of apoptosis demonstrated antagonism between paclitaxel and lovastatin. In BHT-101 cells, however, neither drug had an apoptotic effect when used individually. There was a variable effect when used in combination, depending on the drug concentrations.Paclitaxel and lovastatin were cytotoxic in two ATC cell lines and increased apoptosis in 8505C cells. However, in these cells, the combination of drugs resulted in antagonism that affected both the cytotoxicity of the compounds and the apoptosis of 8505C cells. The combination of paclitaxel and lovastatin did not enhance the treatment effect in ATC cell lines.

There is little consensus on the optimal treatment approach for newly diagnosed patients. The present study aims to provide additional evidence by evaluating a series of patients diagnosed with anaplastic thyroid carcinoma (ATC) and analyzing factors related to increased survival. This was a retrospective cohort report structured according to the Strengthening the Reporting of Observational studies in Epidemiology (STROBE) guideline. Demographics, chief complaint, history of prior thyroid cancer, stage at presentation, management modalities (surgery, chemotherapy, radiotherapy, or observation), completeness or resection, and survival period since initial diagnosis were reviewed for patients with documentation of histologic ATC diagnosis between 2003 and 2016. The median survival period for 34 patients (11 males, 23 females) was 93.5 days. Patients aged 70 or younger (111 days) tended to survive longer than those older 70 (88 days) (P = .081). Observation, surgery only, radiotherapy only, and chemo-radiotherapy after surgery group showed median survival of 88 days, 49 days (range 14-528), 61.5 days, and 225 days, respectively. There was also no significant difference in survival between the 10 (29.4%) stage IVb (225 days) and 23 (67.7%) IVc (88 days) patients (P = .242). The median survival of the R1 resection group was 514 days while that of the R2 group was 102 days (P = .338). There were no significant difference between patients with the de novo ATC (112 days) and patients with papillary thyroid carcinoma origin ATC (99 days) (P = .297). Results from our series of 34 patients with ATC show that more intense combination of surgery and chemo-radiotherapy tends to secure a longer survival period. Therefore we recommend a multi-modality approach after a comprehensive consultation with the patient.

Endoscopic mucosal resection (EMR) is a relatively new treatment option for early gastric cancer (EGC). However, cases of incomplete EMR resulting in a positive lateral margin or submucosal invasion (positive vertical margin) have been reported. We conducted this study to evaluate the role of surgery after incomplete EMR for EGC.We analyzed 19 patients who underwent gastrectomy as a result of an incomplete EMR. The patients were divided into three groups according to the type of incomplete EMR: a positive lateral margin (LM) group (n = 9), a positive vertical margin (VM) group (n = 4), and a positive lateral and vertical margin (LM + VM) group (n = 6).The positive residual tumor rate and the positive lymph node rate were 44.4% (4/9) and 0% (0/9) in the LM group, 50.0% (2/4) and 25.0% (1/4) in the VM group, and 83.3% (5/6) and 16.7% (1/6), LM + VM group, respectively. Curative resection was performed in all patients and there was no recurrence in 30.8 months of follow-up.Radical surgery is recommended for patients with a positive lateral resection margin or submucosal invasion, or both, after EMR for EGC, because of the possibility of residual tumor or lymph node metastasis.

Although postoperative spindle cell nodules have occasionally been found in the lower genitourinary tract,1-3 their presence in post thyroidectomy sites has been reported in only one case.4 In addition, diagnosis by fine needle aspiration (FNA) has not been established. Here, we report on characteristic cytologic findings for a postoperative spindle cell nodule arising in the post-thyroidectomy site.

PURPOSE To assure the surgical completeness of the bilateral axillo-breast approach (BABA) endoscopic thyroidectomy (ET), we compared ET and open thyroidectomy (OT) by means of the radioactive iodine (RAI) uptake of remnant thyroid. MATERIALS AND METHODS From January 2003 to May 2007, 46 patients who had received RAI ablation after total thyroidectomy because of papillary thyroid microcarcinoma were enrolled. Of total, 25 patients underwent ET and the other 21 underwent OT. The RAI activity of remnant thyroid was measured by the neck-to-skull uptake ratio on the first postoperative RAI ablation scan. Stimulated thyroglobulin levels, the total number of RAI ablation sessions, and doses of RAI for completion of ablation were also compared. RESULTS There were no significant differences in regards of the RAI uptake ratio, the stimulated thyroglobulin level, the total number of RAI ablation sessions, and doses of RAI for completion of ablation, between ET and OT groups. CONCLUSION The completeness of the surgical removal by BABA ET was comparable with that of OT. The BABA ET might give a safe option for patients with low-risk thyroid cancer.

Purpose: For the atypical cases of fine needle aspiration (FNA) cytology of thyroid nodules, ultrasonographic findings are a primary guideline for the surgical treatment. However, they have the intrinsic risk of overtreatment, as well. In this study we examined whether the Bethesda system could provide a real effect on the diagnostic rate of atypical cytology, and thereby reduce the number of cases diagnosed as atypical from FNA cytology. Methods: We reviewed 166 cases diagnosed as atypical by FNA cytology at this institute between the years 2005 to 2010. We classified these cases on the basis of ultrasonographic and cytological findings and compared them with the histological results. Results: Ultrasonographically, findings suspicious for malignancy and indeterminate were associated with 83.7% and 47.2% of malignancy rates, respectively. Cytopathologically, the malignancy rates varied according to the main cytological features and the highest malignancy rate was 77.3%. Based on the Bethesda system, 39.2% of the cases diagnosed as atypical could be grouped into the category of suspicious for malignancy and yielded a malignancy rate of 76.9%. Conclusion: Although ultrasonography provides an excellent guideline for the surgical treatment of atypical cases, it also showed considerable risk of overtreatment. The Bethesda system did not offer definitive effects on the rate of atypical cytology, but this system seemed to provide stricter boundaries for the atypical cytology and to aid in reducing the rates thereof. This in turn may permit that more limited cases are allotted to ultrasonographic decision making.

Cervical lymph node metastases are quite common in papillary thyroid cancer (PTC) and they usually spread in a contiguous fashion. However, "skip metastasis," defined as lateral lymph node metastasis without central lymph node metastasis, also occurs in patients with PTC. There is little information regarding skip metastasis in papillary thyroid microcarcinoma (PTMC). The goal of this study was to determine the prevalence and associated clinical and imaging features of skip metastasis in PTMC.We performed a retrospective study of 245 patients with PTMC who underwent either thyroidectomy and central lymph node dissection or thyroidectomy, central lymph node dissection, and lateral lymph node dissection if preoperative ultrasonography or computed tomography suggested lateral node metastasis. Clinicopathologic results were reviewed, and the patterns of cervical lymph node metastasis were analyzed.Cervical lymph node metastases were present in 26.5% of cases. The frequency of lymph node metastases was 21.8% in the group that only had thyroidectomy and central lymph node dissection and 51.3% in the group that had thyroidectomy, central lymph node dissection, and lateral lymph node dissection. Younger age, larger tumor size, multiplicity, bilaterality, encapsulation, extrathyroid extension, and lymphatic invasion were associated with metastasis to nodes in the central or lateral compartment. Lateral lymph node dissection was performed in 15.9% of patients. Skip metastasis was observed in 7.7% of the cases in which combined central and lateral node dissection was performed. No features of the primary thyroid tumor could be associated with the development of skip metastasis.Skip metastases occur in a minority of patients with PTMC. We recommend, therefore, that preoperative studies in patients suspected of having PTMC focus not only on nodes in the central compartment but also lateral cervical nodes since the information obtained would guide the extent of surgery.

Endoscopic techniques have recently been applied to thyroid surgery. We developed the bilateral axillo-breast (BAB) approach for total thyroidectomy. The aims of this study were to evaluate the completeness of this approach for total thyroidectomy and to compare complications between endoscopic thyroidectomy and conventional open thyroidectomy. We analyzed 198 patients who underwent open thyroidectomy and 103 patients who underwent endoscopic thyroidectomy for papillary thyroid microcarcinoma between January 2003 and June 2006 at Seoul National University Hospital. The postoperative thyroglobulin (TG) level was used to assess the completeness of the two methods. Complications such as hypocalcemia or vocal cord palsy were also evaluated. The mean hospitalization period was 3.18 days following open thyroidectomy and 3.04 days after endoscopic thyroidectomy. The 3-month postoperative TG levels were

Purpose To analyze the incidence and patterns of calcification of papillary thyroid microcarcinoma (PTMC) on neck ultrasonography (NUS) and assess the clinical implications of calcification, especially for neck node metastasis. Methods The clinical data of 379 patients with PTMC who underwent thyroidectomy between January and December 2011 were retrospectively analyzed. PTMC lesions were classified into four subgroups according to their calcification patterns on preoperative NUS: microcalcification, macrocalcification, rim calcification, and noncalcification. The clinicopathologic characteristics were compared between the patients with and without calcification, and among the four subgroups. Results Calcifications were detected on NUS in 203 patients (53.5%) and central neck node metastasis was observed in 119 patients (31.3%). Calcification was associated with larger tumor size (0.68 cm vs. 0.54 cm), higher rate of lymph node metastasis (38.6% vs. 23.2%) and higher lymph node ratio (0.11 vs. 0.06) compared to noncalcification (All P < 0.05). In addition, the extent of calcification correlated with lesion size (0.67 cm vs. 0.69 cm vs. 0.85 cm). Further, the likelihood of lymph node metastasis also correlated with the extent of calcification in the order of non-, micro- and macrocalcification (23.3%, 36.8%, and 44.1%, respectively). The calcification rate was higher in patients with lymph node metastasis than those without it (65.5% vs.47.7%) (All P < 0.05). Conclusion PTMC patients positive for calcification on NUS had a higher rate of lymph node metastasis, and a higher lymph node ratio compared to noncalcification patients. Calcification patterns should be assessed carefully in patients with PTMC by preoperative NUS.

Purpose Due to the increased prevalence of thyroid cancer, it has been frequently detected in breast cancer patients recently. The aim of this study was to evaluate the clinicopathologic characteristics of thyroid cancer in breast cancer patients with respect to prognosis and treatment. Methods From August 1998 to September 2012, 101 breast cancer patients were diagnosed with thyroid cancer (BT group). One hundred ninety-three female patients with a thyroid malignancy that underwent thyroidectomy in 2008 were recruited as controls (oT group). The clinicopathologic results of these two groups were compared. Results Patients were older (51.40 vs. 47.16, P < 0.001), mean tumor size was smaller (0.96 cm vs. 1.43 cm, P < 0.001), and extrathyroidal extension was less common in the BT group. In both groups, papillary thyroid carcinoma was the most common type of thyroid malignancy. T and N classifications of thyroid cancer were less severe in the BT group, but group TNM stages were similar. Endoscopic thyroid surgery was performed in 12.9% of patients in the BT group and in 6.7% of patients in the oT group. Postoperative radioactive iodine ablation was performed less often in the BT group (P < 0.001). Group recurrence rates were not significantly different. Conclusion Thyroid cancer in breast cancer patients was diagnosed at earlier status than ordinary thyroid cancer. However, the prognosis of thyroid cancer in breast cancer patients was not superior to that in patients with thyroid cancer alone. Radioactive iodine ablation was performed less often and endoscopic surgery could be performed in breast cancer patients.

Purpose: There have been controversies on the scope of central lymph node dissection (CND) in papillary thyroid cancer (PTC). We performed this study to determine the role of CND for patients having PTC measuring 2 cm or less. Methods: 530 cases of PTC less than 2 cm had undergone lobectomy plus isthmectomy (LI) with CND or without CND. Clinicopathologic records and clinical outcome were evaluated, retrospectively. Results: Comparing recurrence rates in LI with CND group (4/174, 2.30%) and LI without CND group (16/356, 4.49%), there was no significant statistical difference in recurrence (P=0.331). We compared 20 patients with recurrences and 510 patients of no recurrence. The size of tumor seemed to influence recurrence (P＜0.001) and the size of tumor developing recurrence was larger than the other (1.11 cm vs. 0.75 cm). When considering division into PTC and papillary thyroid microcarcinoma (PTMC), PTMC showed less recurrence significantly (P=0.006). No other variables such as age, sex, tumor location, extrathyroidal extension seemed to be related to the recurrence. Conclusion: We could not find any relevant role of CND to prevent recurrence either locally or regionally in cases of no lymph node metastasis after CND for patients having PTC measuring 2 cm or less. Moreover, prophylactic CND is not mandatory for all cases of PTC less than 2 cm. (J Korean Surg Soc 2010;79:332-339)