Background and Objectives: Studies investigating the correlation between papillary thyroid carcinoma (PTC) tumor size and the prevalence of the B-type Raf kinase (BRAF) mutation have yielded conflicting results. Therefore, we evaluated the prevalence of BRAF mutation according to tumor size in a large cohort of PTC patients to clarify this association. Materials and Methods: We retrospectively analyzed 6,438 patients with surgically diagnosed classic PTC between January 2009 and December 2017 at Samsung Medical Center, Seoul, Republic of Korea.During the study period, BRAF mutation testing was attempted on all fine-needle aspiration specimens, except for a small number of inadequate specimens. All other histologic subtypes were excluded. The prevalence of BRAF mutation was assessed based on tumor size, and further analyzed by age group and sex according to tumor size. Results: The overall prevalence of BRAF mutation was 79.2%. When PTCs ≤1 cm were excluded, the prevalence was 77.2%. The prevalence significantly decreased with increasing tumor size (p for trend ＜0.001). It was significantly higher in men than in women (p=0.013), but did not differ by age. The inverse correlation between tumor size and prevalence was prominent in patients aged 20-49 years but was less distinct in those aged 50 years and older. Conclusion In this large cohort of patients with PTC, the prevalence of BRAF mutation significantly decreased with increasing tumor size. These findings suggest that BRAF mutation is enriched in smaller surgically treated classic PTCs and may provide a hypothesis-generating clue regarding its role in early PTC development, although selection bias cannot be excluded.

Objectives: Endoscopic submucosal dissection (ESD) has become a standard minimally invasive treatment for selected patients with early gastric cancer (EGC). This study presents the first nationwide survey of patients with EGC treated with ESD in 2023, conducted by the Korean College of Helicobacter and Upper Gastrointestinal Research. Methods: Data were retrospectively collected from participating referral centers across Korea using a standardized case report form covering patient characteristics, tumor features, procedural details, histopathological findings, and clinical outcomes. Descriptive and comparative analyses were conducted to summarize nationwide ESD practice patterns and outcomes. Results: Data from 5460 ESD cases from 5250 patients across 27 institutions were analyzed. The mean age was 67.4 years, with 74.1% males. Multiple synchronous lesions were identified in 3.7%. Most lesions were located in the lower third of the stomach (64.0%), and differentiated-type adenocarcinomas accounted for 87.8%. The en bloc and complete resection rates were 99.2% and 91.4%, respectively. Curative resection was achieved in 80.5%, whereas local non-curative resection (L-NCR) and surgical non-curative resection (S-NCR) were identified in 2.8% and 16.7%, respectively. Additional surgery was performed more frequently in patients with S-NCR than in those with L-NCR (59.3% vs. 24.7%). The bleeding and perforation rates were 3.6% and 0.9%, respectively, and were mostly managed conservatively or endoscopically. The median length of hospitalization was 4.0 days. Conclusions This first nationwide survey provides a comprehensive overview of the current practice of EGC treatment using ESD in Korea, demonstrating high technical success and safety, and establishing a baseline dataset for future longitudinal research.

Purpose: Endoscopic submucosal dissection (ESD) has become a standard minimally invasive treatment for selected patients with early gastric cancer (EGC). This study presents the first nationwide survey of patients with EGC treated with ESD in 2023, conducted by the Korean College of Helicobacter and Upper Gastrointestinal Research. Materials and Methods: Data were retrospectively collected from participating referral centers across Korea using a standardized case report form covering patient characteristics, tumor features, procedural details, histopathological findings, and clinical outcomes.Descriptive and comparative analyses were conducted to summarize nationwide ESD practice patterns and outcomes. Results: Data from 5,460 ESD cases from 5,250 patients across 27 institutions were analyzed. The mean age was 67.4 years, with 74.1% males. Multiple synchronous lesions were identified in 3.7%. Most lesions were located in the lower third of the stomach (64.0%), and differentiated-type adenocarcinomas accounted for 87.8%. The en bloc and complete resection rates were 99.2% and 91.4%, respectively. Curative resection was achieved in 80.5%, whereas local non-curative resection (L-NCR) and surgical non-curative resection (S-NCR) were identified in 2.8% and 16.7%, respectively. Additional surgery was performed more frequently in patients with S-NCR than in those with L-NCR (59.3% vs. 24.7%). The bleeding and perforation rates were 3.6% and 0.9%, respectively, and were mostly managed conservatively or endoscopically. The median length of hospitalization was 4.0 days. Conclusions This first nationwide survey provides a comprehensive overview of the current practice of EGC treatment using ESD in Korea, demonstrating high technical success and safety, and establishing a baseline dataset for future longitudinal research.

Sudden hearing loss rarely presents as an initial manifestation of a hematologic disorder, although it can result from various factors. A 48-year-old male had sudden hearing loss in both ears. The pure tone audiometry and audiometry brainstem response revealed profound hearing loss in both ears. Further examination indicated an elevated leukocyte count, and a temporal bone magnetic resonance image suggested potential bleeding in the cochlear and labyrinth of both ears. Upon consultation with hematologic oncology, chronic myeloid leukemia was diagnosed. Hearing loss in leukemia patients is attributed to leukemic infiltration, hemorrhage, infection, and hyperviscosity. Following treatment using tyrosine kinase inhibitor for chronic myeloid leukemia, the leukocyte count was normalized. However, on the 90th day of treatment, both profound hearing loss persisted. We suspect that the cause of sudden hearing loss may be related to hemorrhage in both cochlear and labyrinth. Accurate diagnosis and treatment are essential for preventing complications.

Objective: The aim of this study was to investigate postoperative imaging findings of patients who underwent breastconserving surgery for cancer and reconstruction with MegaDerm® (sheet-type and pellet-type), analyzing false positives and recurrences, using multi-modality images. Materials and Methods: This study included 201 women (age range: 28–81 years, mean age ± standard deviation: 53.2 ± 8.6 years) who underwent breast-conserving surgery and immediate reconstruction with MegaDerm®. Post-surgery, each patient underwent at least one mammography (MG), ultrasonography (US), and MRI, totaling 713 MG, 1063 US, and 607 MRI examinations. Postoperative images were reviewed separately for the two types of MegaDerm®, and suspicious imaging findings (false positives and recurrences) were analyzed, with a particular focus on the findings in direct contact with MegaDerm®. Results: MegaDerm® appeared as a circumscribed mass with homogeneous iso- or high density on MG, posterior shadowing on US, and no enhancement on MRI. Calcification was more common and increased in size in sheet-type MegaDerm®, while pellet-type often exhibited irregular margins. Nine out of 17 false positives had suspicious findings in direct contact with MegaDerm®, and six out of nine recurrences showed similar findings. Common suspicious findings included calcifications, asymmetries, and MegaDerm® irregularities on MG; masses and MegaDerm® irregularities on US; and enhancing masses and MegaDerm® irregularities with enhancement on MRI. Notably, MegaDerm® irregularity with calcification was observed on MG and US in only one recurrence case. In 44.4% (4/9) of false-positives in direct contact with MegaDerm®, suspicious findings showed no change or resolution on follow-up. Conclusion Suspicious imaging findings in direct contact with MegaDerm® may be associated with false positives or recurrences. Therefore, it is essential to recognize these characteristic findings and review the patient’s history of MegaDerm® insertion when in doubt.

Sudden hearing loss rarely presents as an initial manifestation of a hematologic disorder, although it can result from various factors. A 48-year-old male had sudden hearing loss in both ears. The pure tone audiometry and audiometry brainstem response revealed profound hearing loss in both ears. Further examination indicated an elevated leukocyte count, and a temporal bone magnetic resonance image suggested potential bleeding in the cochlear and labyrinth of both ears. Upon consultation with hematologic oncology, chronic myeloid leukemia was diagnosed. Hearing loss in leukemia patients is attributed to leukemic infiltration, hemorrhage, infection, and hyperviscosity. Following treatment using tyrosine kinase inhibitor for chronic myeloid leukemia, the leukocyte count was normalized. However, on the 90th day of treatment, both profound hearing loss persisted. We suspect that the cause of sudden hearing loss may be related to hemorrhage in both cochlear and labyrinth. Accurate diagnosis and treatment are essential for preventing complications.

Objective: The aim of this study was to investigate postoperative imaging findings of patients who underwent breastconserving surgery for cancer and reconstruction with MegaDerm® (sheet-type and pellet-type), analyzing false positives and recurrences, using multi-modality images. Materials and Methods: This study included 201 women (age range: 28–81 years, mean age ± standard deviation: 53.2 ± 8.6 years) who underwent breast-conserving surgery and immediate reconstruction with MegaDerm®. Post-surgery, each patient underwent at least one mammography (MG), ultrasonography (US), and MRI, totaling 713 MG, 1063 US, and 607 MRI examinations. Postoperative images were reviewed separately for the two types of MegaDerm®, and suspicious imaging findings (false positives and recurrences) were analyzed, with a particular focus on the findings in direct contact with MegaDerm®. Results: MegaDerm® appeared as a circumscribed mass with homogeneous iso- or high density on MG, posterior shadowing on US, and no enhancement on MRI. Calcification was more common and increased in size in sheet-type MegaDerm®, while pellet-type often exhibited irregular margins. Nine out of 17 false positives had suspicious findings in direct contact with MegaDerm®, and six out of nine recurrences showed similar findings. Common suspicious findings included calcifications, asymmetries, and MegaDerm® irregularities on MG; masses and MegaDerm® irregularities on US; and enhancing masses and MegaDerm® irregularities with enhancement on MRI. Notably, MegaDerm® irregularity with calcification was observed on MG and US in only one recurrence case. In 44.4% (4/9) of false-positives in direct contact with MegaDerm®, suspicious findings showed no change or resolution on follow-up. Conclusion Suspicious imaging findings in direct contact with MegaDerm® may be associated with false positives or recurrences. Therefore, it is essential to recognize these characteristic findings and review the patient’s history of MegaDerm® insertion when in doubt.

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.

Sudden hearing loss rarely presents as an initial manifestation of a hematologic disorder, although it can result from various factors. A 48-year-old male had sudden hearing loss in both ears. The pure tone audiometry and audiometry brainstem response revealed profound hearing loss in both ears. Further examination indicated an elevated leukocyte count, and a temporal bone magnetic resonance image suggested potential bleeding in the cochlear and labyrinth of both ears. Upon consultation with hematologic oncology, chronic myeloid leukemia was diagnosed. Hearing loss in leukemia patients is attributed to leukemic infiltration, hemorrhage, infection, and hyperviscosity. Following treatment using tyrosine kinase inhibitor for chronic myeloid leukemia, the leukocyte count was normalized. However, on the 90th day of treatment, both profound hearing loss persisted. We suspect that the cause of sudden hearing loss may be related to hemorrhage in both cochlear and labyrinth. Accurate diagnosis and treatment are essential for preventing complications.

Objective: The aim of this study was to investigate postoperative imaging findings of patients who underwent breastconserving surgery for cancer and reconstruction with MegaDerm® (sheet-type and pellet-type), analyzing false positives and recurrences, using multi-modality images. Materials and Methods: This study included 201 women (age range: 28–81 years, mean age ± standard deviation: 53.2 ± 8.6 years) who underwent breast-conserving surgery and immediate reconstruction with MegaDerm®. Post-surgery, each patient underwent at least one mammography (MG), ultrasonography (US), and MRI, totaling 713 MG, 1063 US, and 607 MRI examinations. Postoperative images were reviewed separately for the two types of MegaDerm®, and suspicious imaging findings (false positives and recurrences) were analyzed, with a particular focus on the findings in direct contact with MegaDerm®. Results: MegaDerm® appeared as a circumscribed mass with homogeneous iso- or high density on MG, posterior shadowing on US, and no enhancement on MRI. Calcification was more common and increased in size in sheet-type MegaDerm®, while pellet-type often exhibited irregular margins. Nine out of 17 false positives had suspicious findings in direct contact with MegaDerm®, and six out of nine recurrences showed similar findings. Common suspicious findings included calcifications, asymmetries, and MegaDerm® irregularities on MG; masses and MegaDerm® irregularities on US; and enhancing masses and MegaDerm® irregularities with enhancement on MRI. Notably, MegaDerm® irregularity with calcification was observed on MG and US in only one recurrence case. In 44.4% (4/9) of false-positives in direct contact with MegaDerm®, suspicious findings showed no change or resolution on follow-up. Conclusion Suspicious imaging findings in direct contact with MegaDerm® may be associated with false positives or recurrences. Therefore, it is essential to recognize these characteristic findings and review the patient’s history of MegaDerm® insertion when in doubt.