Objective:Given the limitations of conventional approaches in managing indeterminate thyroid nodules, there remains an unmet need for non-invasive assistant tools to improve risk stratification. This study aimed to evaluate the clinical applicability of an artificial intelligence (AI) model for thyroid nodules with atypia of undetermined significance (AUS) cytology. Methods:We retrospectively reviewed patients who underwent fine-needle aspiration (FNA) for thyroid nodules between January 2019 and December 2020 across five medical institutions in Korea. Nodules initially diagnosed as AUS and later confirmed as benign or malignant were included. A previously developed deep learning-based AI model, AI-Thyroid, was employed to provide binary classifications (benign or malignant) and malignancy risk estimates. Results:A total of 165 thyroid nodules were analyzed. The median (interquartile range) longest diameter was 1.30 cm (0.80-2.10), and the malignancy rate of the cohort was 39%. In binary classification tasks, the model achieved a sensitivity of 0.91 and a negative predictive value of 0.87. The area under the curve (AUC) based on estimated malignancy risk was 0.75 (95% confidence interval (CI): 0.68-0.83), and the AUC derived from K-TIRADS categories 2-5 was 0.76 (95% CI: 0.69-0.83), indicating comparable diagnostic accuracy with the traditional scoring system. Subgroup analyses demonstrated that the model achieved a sensitivity of 98% in nodules smaller than 1.5 cm. Conclusion:AI-assisted ultrasound analysis offers supplementary diagnostic information for thyroid nodules with AUS cytology. Its high sensitivity and negative predictive value may assist clinicians in decision-making processes, particularly for small, low-risk thyroid nodules.

Background:Papillary thyroid carcinoma (PTC) located in the isthmus generally has been known to have more extrathyroidal extension (ETE), lymph node involvement, and multifocality. The purpose of this study was to determine the clinical significance of an isthmic location of PTC.Methods:The records of 160 patients who underwent a total thyroidectomy due to a single, dominant isthmic PTC were retrospectively reviewed. The characteristics of isthmic cancer were compared with those of unilateral-lobar cancer in a PTC cohort at Seoul St. Mary's hospital. After propensity score matching for age, sex, and tumor size, 160 isthmic PTCs and 800 unilateral-lobar PTCs were compared. The clinicopathologic characteristics were analyzed to evaluate the prognostic significance of an isthmic tumor location.Results:The isthmic group was significantly older (49.6 vs. 46.8 years, P=0.007) and had a smaller mean tumor size (0.8±0.4 vs. 1.0±0.7 cm, P<0.001) than the unilateral-lobar group. After propensity score matching, tumor size categories, ETE, multifocality, nodal metastasis and proportion of patients with more than five metastatic lymph nodes were similar in both groups. However, N1b cases were more frequent in the unilateral-lobar group both before and after propensity score matching. In multivariate analysis, isthmic location was not correlated with gross ETE, multifocality, and higher-risk N1 disease. Younger age and more than five metastatic nodes increased the risk of PTC recurrence. However, isthmic tumor location was not significantly correlated with recurrence-free survival.Conclusions:Isthmic location is not an independent risk factor for aggressive clinicopathologic features and is not related to PTC recurrence.

A 58-year-old woman visited the hospital complaining of fatigue and indigestion lasting for more than 3 months. She had no medical history other than taking a calcium plus vitamin D supplement for osteopenia. The initial blood test showed a high calcium level of 14.0 mg/dL. Additional tests were performed to differentially diagnose hypercalcemia. The blood test results were as follows: serum parathyroid hormone (PTH)=247.0 pg/mL, PTH-related peptide <1.0 pg/mL, phosphorous=2.6 mg/dL, 25-hydroxy-vitamin D=14.5 pg/mL, creatinine=1.09 mg/dL, and 24 hr urine calcium=215 mg/dL. A 4.5 cm sized cystic lesion on the intra-thyroidal space was confirmed on neck sonography and 4-dimensional parathyroid computed tomography, but technetium-99m methoxyisobutylisonitrile parathyroid scintigraphy showed equivocal results. After removal of the cystic lesion, serum calcium and PTH were normalized, and parathyroid lipoadenoma was confirmed in the postoperative pathology. Clinical features of parathyroid lipoadenoma are known to be similar to common parathyroid adenoma, but imaging studies often report negative findings. Therefore, it is necessary to better understand this rare disease for the differential diagnosis. For the final diagnosis and treatment of this disease, parathyroidectomy with intraoperative PTH measurement may be required.

Background:Active surveillance (AS) has become an alternative treatment approach for papillary thyroid microcarcinoma (PTMC). The purpose of this study is to uncover the clinicopathological factors associated with high-risk nodal disease in order to select proper candidates for AS of PTMC.Methods:We retrospectively reviewed 5,329 patients with PTMC without extrathyroidal extension (ETE) who underwent thyroidectomy with central compartment neck dissection (CCND) between 2007 and 2021 at Seoul St. Mary's Hospital. Patients with more than five metastatic lymph nodes (MLNs) (higher-risk N1 disease) and/or lateral neck node metastases (N1b disease) were defined as having high-risk nodal disease. The clinicopathological factors associated with high-risk nodal disease were analyzed.Results:A total of 415 (7.8%) patients had higher-risk N1 disease. These patients were younger on average, included a higher proportion of males, and had a larger tumor size and more frequent capsular invasion and multifocality compared with other patients. For the tumor size, a cutoff value of 0.65 cm was the best predictor of nodal risk groups. In a multivariate analysis, the independent risk factors associated with higher-risk N1 disease were younger age, male sex, tumor size >0.65 cm, and the presence of capsular invasion and/or multifocality. A total of 246 (4.6%) patients had N1b disease at initial diagnosis. In a multivariate analysis, the independent risk factors associated with N1b disease were younger age, male sex, tumor size >0.65 cm, and the presence of capsular invasion and/or multifocality.Conclusions:Young age, male sex, tumor size >0.65 cm, and presence of capsular invasion and/or multifocality can be considered risk factors for high-risk nodal disease in PTMC. Therefore, cautious observation is necessary for AS of patients with these characteristics.

Background: It remains controversial whether prophylactic central compartment neck dissection (pCCND) is necessary in cases of stage T1-T2 cN0 papillary thyroid carcinoma (PTC). Some studies have demonstrated the benefits of pCCND on oncologic outcomes, whereas others reported that any advantages were insignificant. The purpose of this study was to investigate the effects of pCCND on cancer recurrence and its pattern in patients with T1-T2 cN0 PTC. Methods: We retrospectively reviewed 2,902 patients with PTC who had undergone thyroidectomy between 2006 and 2012 at Seoul St. Mary's Hospital: 2,099 patients had undergone pCCND and thyroidectomy (pCCND group), whereas 803 did not undergo pCCND (non- pCCND group). We investigated the effects of pCCND on cancer recurrence by comparing these two groups. Recurrence was classified according to the location of the recurrence. Results: The mean follow-up period was 112 months. The mean patient age was significantly younger in the pCCND group than in the non-pCCND group. There were no statistically significant differences in the distribution of sex, tumor size, or thyroidectomy extension between the groups. In the pCCND group, 883 (42%) patients showed evidence of N1a disease, and the mean number of metastatic lymph nodes was 1.26 +/- 2.2. Recurrence occurred in 67 (2.3%) patients in the total cohort. Recurrence was observed in 20 (2.5%) and 47 (2.2%) patients in the non-pCCND and pCCND groups, respectively, but there were no significant differences between the groups (P=0.687). When analyzed by the site of recurrence, 50% and 4.3% of recurrent disease in the non-pCCND and pCCND groups, respectively, occurred in the central compartment (P<0.001). There were no differences between the two groups in recurrent disease at other sites. The 15-year cumulative central compartment recurrence-free survival (RFS) rates of patients in the non-pCCND and pCCND groups were 99% and 100%, respectively (P<0.001). In the multivariate analysis, not performing pCCND was the only independent risk factor related to central compartment RFS, and the hazard ratio was 13.362 [95% confidence interval (CI): 2.928-60.986; P<0.001]. Conclusions: The omission of pCCND was found to be an independent risk factor for recurrence in the central compartment in patients with T1-T2 cN0 PTC.

Searchable abstracts of presentations at key conferences in endocrinology ISSN 1470-3947 (print) | ISSN 1479-6848 (online)

Background The treatment for papillary thyroid cancer (PTC) has become more conservative, but still no specific guidelines exist for managing isthmic PTC. This study analyzed the outcomes from isthmusectomy in single isthmic PTC and compared it with those for patients who previously had undergone a total thyroidectomy. Methods An isthmusectomy with prophylactic central compartment neck dissection (pCCND) was planned for a single isthmic PTC between 2014 and 2018 (isthmusectomy group). For cases with gross extrathyroidal extension (ETE) or multiple nodal metastasis, the procedure was converted to a total thyroidectomy. The study analyzed the characteristics and outcomes of the isthmusectomy group. Additionally, the results were compared with those of the isthmusectomy-feasible group who met the eligibility criteria for isthmusectomy among total thyroidectomies performed between 2009 and 2013. Results Of the 90 patients in the isthmusectomy group, 81 received isthmusectomy and 9 had conversion to a total thyroidectomy. Microcarcinoma occurred in 72 cases and gross ETE in 3 cases. One patient showed occult satellite cancer, and seven patients showed more than five metastatic nodes. Transient hypocalcemia developed in five and patients and permanent hypocalcemia in one patient with total thyroidectomy. Of 46 patients who began hormone replacement postoperatively, 13 completely stopped taking medication during the follow-up period. Metachronous PTC was diagnosed for one patient 12 months after isthmusectomy. The isthmusectomy group and the isthmusectomy-feasible group showed similar clinicopathologic properties including multifocality, ETE, and nodal metastasis. However, the isthmusectomy group showed significantly less transient or permanent hypocalcemia and thyroid hormone dependency. Conclusions Isthmusectomy with pCCND may be a feasible alternative for properly selected isthmic PTC, resulting in a better quality of life than total thyroidectomy.

Background and Objectives The impacts of prophylactic central compartment neck dissection (pCCND) on the prognosis of papillary thyroid cancer (PTC) are controversial. The aim of this study is to evaluate the relationship between nodal factors of pCCND and the prognosis of PTC patients. Materials and Methods A total of 1754 patients who underwent thyroidectomy with pCCND were retrospectively reviewed. Nodal factor was defined as the number of metastatic lymph node (MLN), lymph node yield (LNY) and lymph node ratio (LNR). In regarding the cutoff of nodal factors, patients were categorized as low/high MLN, LNR and LNY group. The correlation of clinicopathologic characteristics including nodal factors and recurrence free survival (RFS) were anlalyzed. Results Of these, 1195 patients underwent thyroidectomy with unilateral pCCND and 559 patients underwent total thyroidectomy with bilateral pCCND. During follow-up, 45 (2.57%) patients showed recurrent disease. Of these, 19 patients underwent bilateral pCCND and 26 cases were unilateral pCCND. Gross extrathyroidal extension (ETE), high MLN and LNR showed statistically significant on RFS in univariate analysis in unilateral pCCND. In multivariate analysis, gross ETE and high LNR were independent risk factor of recurrence in unilateral pCCND. In bilateral pCCND, larger tumor size, minimal ETE, high MLN and LNR were significant correlation with RFS in univariate analysis. However, in multivariate analysis, multiple larger tumor and high LNR showed significant correlation with RFS. LNY was not statistically significant in both unilateral and bilateral pCCND. Conclusion In regarding nodal factors, high LNR was only independent risk factor to worse RFS in both unilateral and bilateral pCCND in cN0 PTC patients.

Purpose: A laparoscopic approach, rather than conventional laparotom y, is the w ell-accepted first choice for excision of an adrenal or perinephric retroperitoneal m ass.The purpose of this study w as to investigate the factors that affect surgical outcom es and analyze the clinical effectiveness of this surgical treatm ent m odality.Methods: W e conducted a retrospective analysis of 62 patients w ho underw ent laparoscopic adrenalectom ies from Septem ber 2007 to February 2013.These operations w ere perform ed by a single surgeon.Dem ographic characteristics, operative data, tum or characteristics, and surgical outcom es w ere analyzed.Results: Of 62 patients, 21 were m en and 41 were wom en.The m ean operative tim e w as 151.16±48.58m inutes and the m ean am ount of blood loss w as 179.51± 161.66 m l.There w ere tw o cases of m etastatic adrenal tum ors that w ere resected com pletely with prolonged survival.There was one case of recurrence during the postoperative period.Preoperatively, it w as only a tum or m easuring 3.5 cm w ithout evidence of m alignancy.Postoperative com plications occurred in three patients.However, there was no case of conversion to laparotom y.Previous history of open abdom inal operation did not affect post-operative outcom es.Conclusion: Laparoscopic approach for adrenal tum ors is indicated regardless of its type or past history of abdom inal surgery.U nless greater than 10 cm , relatively large tum ors can be safely rem oved using this m ethod.In particular, due to the possibility of m alignant potential, aggressive surgical intervention is recom m ended for tum ors m easuring betw een 3 and 5 cm .Use of a laparoscopic approach is associated with low risk of surgical com plication and the benefits outweigh the disadvantages.