Purpose: We aimed to evaluate the precision of preoperative colonoscopic tattooing and intraoperative colonoscopic tumor localization in determining distal surgical margins for leftsided colorectal cancer surgery. Methods: This retrospective study included 30 patients who underwent laparoscopic colorectal surgery, preoperative colonoscopic tattooing, and intraoperative colonoscopic localization for colorectal cancer at our center between July 2020 and March 2024. Clinical data were collected, and the precision of these methods was assessed by measuring the differences between the target resection margin and the actual pathological resection margin. Results: In four patient cases, the indocyanine green tattoo was not visible in the laparoscopic surgical field. The average stained length of the tattoo was 2.89 cm, with a mean distance of 1.18 cm between the low margin of the tattoo and the cancer. The difference between the target distal resection margin by intraoperative colonoscopic localization and the actual pathological resection margin was 0.88 cm. No complications related to the intraoperative colonoscopy were observed. Conclusion Preoperative tattooing showed limitations, such as spreading and occasional invisibility. Intraoperative colonoscopic localization proved to be an effective method for achieving more precise distal surgical margins in left-sided colorectal cancer surgery.

Purpose: We aimed to evaluate the precision of preoperative colonoscopic tattooing and intraoperative colonoscopic tumor localization in determining distal surgical margins for leftsided colorectal cancer surgery. Methods: This retrospective study included 30 patients who underwent laparoscopic colorectal surgery, preoperative colonoscopic tattooing, and intraoperative colonoscopic localization for colorectal cancer at our center between July 2020 and March 2024. Clinical data were collected, and the precision of these methods was assessed by measuring the differences between the target resection margin and the actual pathological resection margin. Results: In four patient cases, the indocyanine green tattoo was not visible in the laparoscopic surgical field. The average stained length of the tattoo was 2.89 cm, with a mean distance of 1.18 cm between the low margin of the tattoo and the cancer. The difference between the target distal resection margin by intraoperative colonoscopic localization and the actual pathological resection margin was 0.88 cm. No complications related to the intraoperative colonoscopy were observed. Conclusion Preoperative tattooing showed limitations, such as spreading and occasional invisibility. Intraoperative colonoscopic localization proved to be an effective method for achieving more precise distal surgical margins in left-sided colorectal cancer surgery.

Purpose: We aimed to evaluate the precision of preoperative colonoscopic tattooing and intraoperative colonoscopic tumor localization in determining distal surgical margins for leftsided colorectal cancer surgery. Methods: This retrospective study included 30 patients who underwent laparoscopic colorectal surgery, preoperative colonoscopic tattooing, and intraoperative colonoscopic localization for colorectal cancer at our center between July 2020 and March 2024. Clinical data were collected, and the precision of these methods was assessed by measuring the differences between the target resection margin and the actual pathological resection margin. Results: In four patient cases, the indocyanine green tattoo was not visible in the laparoscopic surgical field. The average stained length of the tattoo was 2.89 cm, with a mean distance of 1.18 cm between the low margin of the tattoo and the cancer. The difference between the target distal resection margin by intraoperative colonoscopic localization and the actual pathological resection margin was 0.88 cm. No complications related to the intraoperative colonoscopy were observed. Conclusion Preoperative tattooing showed limitations, such as spreading and occasional invisibility. Intraoperative colonoscopic localization proved to be an effective method for achieving more precise distal surgical margins in left-sided colorectal cancer surgery.

Background and Objectives: Telomerase reverse transcriptase (TERT) promoter mutations are a poor prognostic factor in differentiated thyroid carcinoma (DTC). However, their prognostic value in anaplastic thyroid carcinoma (ATC) is unclear. Therefore, we investigated whether TERT promoter mutations also act as an independent poor prognostic factor in ATC. Materials and Methods: We reviewed the medical records of 41 patients with ATC who underwent the TERT promoter mutations test at Samsung Medical Center between November 1995 and December 2022. The aggressive treatment group was defined as patients who underwent surgery, external radiotherapy, and systemic therapy. Results: Among 41 patients, 15 (36.6%) showed TERT promoter mutations. There only differences in the clinicopathological characteristics between the TERT-mutant and wild-type groups were tumor size and coexistence of DTC. Median tumor size in the TERT-mutant group was 5.1 cm (3.0-11.0), which was significantly larger than that in the wild-type group (4.1 cm, 0.8-8.0, p=0.010). Nevertheless, the TERT-mutant group received relatively more aggressive treatment (53.3% vs. 19.2%, p=0.056), and the overall survival of the TERT-mutant group was longer than that of the wild-type group (9.4 months [0.4-51.5] vs. 7.1 months [0.4-49.5]), but its difference was not significant (p=0.458). In multiple regression analysis, distant metastasis was a significant prognostic factor, but TERT promoter mutation was not. Conclusion Unlike in DTC, TERT promoter mutations were not an independent poor prognostic factor in ATC.

Background and Objectives: Telomerase reverse transcriptase (TERT) promoter mutations are a poor prognostic factor in differentiated thyroid carcinoma (DTC). However, their prognostic value in anaplastic thyroid carcinoma (ATC) is unclear. Therefore, we investigated whether TERT promoter mutations also act as an independent poor prognostic factor in ATC. Materials and Methods: We reviewed the medical records of 41 patients with ATC who underwent the TERT promoter mutations test at Samsung Medical Center between November 1995 and December 2022. The aggressive treatment group was defined as patients who underwent surgery, external radiotherapy, and systemic therapy. Results: Among 41 patients, 15 (36.6%) showed TERT promoter mutations. There only differences in the clinicopathological characteristics between the TERT-mutant and wild-type groups were tumor size and coexistence of DTC. Median tumor size in the TERT-mutant group was 5.1 cm (3.0-11.0), which was significantly larger than that in the wild-type group (4.1 cm, 0.8-8.0, p=0.010). Nevertheless, the TERT-mutant group received relatively more aggressive treatment (53.3% vs. 19.2%, p=0.056), and the overall survival of the TERT-mutant group was longer than that of the wild-type group (9.4 months [0.4-51.5] vs. 7.1 months [0.4-49.5]), but its difference was not significant (p=0.458). In multiple regression analysis, distant metastasis was a significant prognostic factor, but TERT promoter mutation was not. Conclusion Unlike in DTC, TERT promoter mutations were not an independent poor prognostic factor in ATC.

Background and Objectives: Telomerase reverse transcriptase (TERT) promoter mutations are a poor prognostic factor in differentiated thyroid carcinoma (DTC). However, their prognostic value in anaplastic thyroid carcinoma (ATC) is unclear. Therefore, we investigated whether TERT promoter mutations also act as an independent poor prognostic factor in ATC. Materials and Methods: We reviewed the medical records of 41 patients with ATC who underwent the TERT promoter mutations test at Samsung Medical Center between November 1995 and December 2022. The aggressive treatment group was defined as patients who underwent surgery, external radiotherapy, and systemic therapy. Results: Among 41 patients, 15 (36.6%) showed TERT promoter mutations. There only differences in the clinicopathological characteristics between the TERT-mutant and wild-type groups were tumor size and coexistence of DTC. Median tumor size in the TERT-mutant group was 5.1 cm (3.0-11.0), which was significantly larger than that in the wild-type group (4.1 cm, 0.8-8.0, p=0.010). Nevertheless, the TERT-mutant group received relatively more aggressive treatment (53.3% vs. 19.2%, p=0.056), and the overall survival of the TERT-mutant group was longer than that of the wild-type group (9.4 months [0.4-51.5] vs. 7.1 months [0.4-49.5]), but its difference was not significant (p=0.458). In multiple regression analysis, distant metastasis was a significant prognostic factor, but TERT promoter mutation was not. Conclusion Unlike in DTC, TERT promoter mutations were not an independent poor prognostic factor in ATC.

Objectives: . The supine sleep position and the rapid eye movement (REM) stage are widely recognized to exacerbate the severity of obstructive sleep apnea (OSA). Position-dependent OSA is generally characterized by an apnea-hypopnea index (AHI) that is at least twice as high in the supine position compared to other sleep positions. However, this condition can be misdiagnosed if a particular sleep stage—REM or non-REM (NREM)—predominates in a specific position. We explored the impact of the sleep stage on positional dependency in OSA. Methods: . Polysomnographic data were retrospectively analyzed from 111 patients with OSA aged 18 years or older, all of whom had an AHI exceeding five events per hour and slept in both supine and non-supine positions for at least 5% of the total sleep time. The overall ratio of non-supine AHI to supine AHI (NS/S-AHI ratio) was compared between total, REM, and NREM sleep. Additionally, a weighted NS/S-AHI ratio, reflecting the proportion of time spent in each sleep stage, was calculated and compared to the original ratio. Results: . The mean NS/S-AHI ratio was consistent between the entire sleep period and the specific sleep stages. However, the NS/S-AHI ratios for individual patients displayed poor agreement between total sleep and the specific stages. Additionally, the weighted NS/S-AHI ratio displayed poor agreement with the original NS/S-AHI ratio, primarily due to discrepancies in patients with mild to moderate OSA. Conclusion . The weighted NS/S-AHI ratio may help precisely assess positional dependency.

Background: The adequate dose of levothyroxine (LT4) for patients who have undergone total thyroidectomy (TT) for differentiated thyroid cancer (DTC) is uncertain. We evaluated the LT4 dose required to achieve mild thyroid-stimulating hormone (TSH) suppression in DTC patients after TT. Methods: The electronic medical records of patients who underwent TT for DTC and received mild TSH suppression therapy were reviewed. Linear regression analysis was performed to evaluate the association between LT4 dose (μg/kg) and an ordinal group divided by body mass index (BMI). We also evaluated the trend in LT4 doses among groups divided by BMI and age. Results: In total, 123 patients achieved mild TSH suppression (0.1 to 0.5 mIU/L). The BMI variable was divided into three categories: <23 kg/m2 (n=46), ≥23 and <25 kg/m2 (n=30), and ≥25 kg/m2 (n=47). In the linear regression analysis, BMI was negatively associated with the LT4 dose after adjusting for age and sex (P<0.001). The LT4 doses required to achieve mild TSH suppression based on the BMI categories were 1.86, 1.71, and 1.71 μg/kg, respectively (P for trend <0.001). Further analysis with groups divided by age and BMI revealed that a higher BMI was related to a lower LT4 dose, especially in younger patients aged 20 to 39 (P for trend=0.011). Conclusion The study results suggest an appropriate LT4 dose for mild TSH suppression after TT based on body weight in patients with DTC. Considering body weight, BMI, and age in estimating LT4 doses might help to achieve the target TSH level promptly.

Background: Malignant struma ovarii (MSO) is a very rare disease in which thyroid cancer originates from the ovary. Because it is rare for endocrinologists to encounter patients with MSO, endocrinologists may have a limited understanding of the disease. Therefore, we analyzed and introduced its incidence and clinical course in a tertiary hospital in Korea. Methods: We retrospectively investigated the clinical data of 170 patients who underwent surgery for struma ovarii at the Department of Obstetrics and Gynecology of Samsung Medical Center from 1994 to May 2023. Results: Among 170 patients with struma ovarii, 15 (8.8%) were diagnosed with MSO. The median age of patients with MSO was 48 years (range, 30 to 74), and the median tumor size was 3.3 cm (range, 0.5 to 11.0). Papillary thyroid carcinoma (46.7%) was the most common subtypes followed by follicular thyroid carcinoma (26.7%). All patients were diagnosed after surgery, with no predictions from preoperative imaging. The surgical extent of gynecological surgery was variable. Four patients (26.7%) underwent thyroidectomy for thyroid cancer, while one underwent total thyroidectomy and radioactive iodine therapy for MSO with peritoneal metastasis. Except for one patient who underwent hemithyroidectomy, thyroid stimulating hormone suppression therapy was performed in four patients. Only 53% of MSO patients were consulted by an endocrinologist. With a median follow-up period of 33 months (range, 4 to 156), 11 patients remained disease-free, one experienced progression with peritoneal seeding, and the remaining one was in treatment. There have been no recurrences or deaths due to MSO. Conclusion An endocrinologist should be involved in establishing a therapeutic plan for MSO, for which the overall prognosis is generally favorable.

Differentiated thyroid cancer demonstrates a wide range of clinical presentations, from very indolent cases to those with an aggressive prognosis. Therefore, diagnosing and treating each cancer appropriately based on its risk status is important. The Korean Thyroid Association (KTA) has provided and amended the clinical guidelines for thyroid cancer management since 2007. The main changes in this revised 2024 guideline include 1) individualization of surgical extent according to pathological tests and clinical findings, 2) application of active surveillance in low-risk papillary thyroid microcarcinoma, 3) indications for minimally invasive surgery, 4) adoption of World Health Organization pathological diagnostic criteria and definition of terminology in Korean, 5) update on literature evidence of recurrence risk for initial risk stratification, 6) addition of the role of molecular testing, 7) addition of definition of initial risk stratification and targeting thyroid stimulating hormone (TSH) concentrations according to ongoing risk stratification (ORS), 8) addition of treatment of perioperative hypoparathyroidism, 9) update on systemic chemotherapy, and 10) addition of treatment for pediatric patients with thyroid cancer.