1.Transformation of Pleomorphic Xanthoastrocytoma with Germline ATM Mutation into a SMARCB1-Deficient Rhabdoid Tumor: A Case Report
Hyeonseung LEE ; Hyun Jin PARK ; Bo Kyung KIM ; Kyung Taek HONG ; Hyoung Jin KANG ; Sung-Hye PARK ; Ji Hoon PHI ; June-Young KOH ; Jung Yoon CHOI
Clinical Pediatric Hematology-Oncology 2026;33(1):34-38
Secondary rhabdoid tumors (RTs) with atypical teratoid/rhabdoid tumor-like features rarely arise from, or coexist with, pleomorphic xanthoastrocytomas (PXAs), and their clinicopathological and molecular characteristics remain poorly understood. We report a 17-year-old girl with a temporal lobe mass that, upon gross total resection, pathologically contained both RT and PXA components. Immunohistochemistry revealed loss of INI1 expression restricted to the RT component, while the PXA area retained INI1. Next-generation sequencing identified a shared BRAF::TRIM24 fusion and homozygous deletion of CDKN2A/2B in both components, indicating a shared clonal origin. Additionally, a germline ATM frameshift mutation (c.5288_5289insGA) was identified in both tumor components, making the first such report in central nervous system tumors. SMARCB1 loss was confined to the RT component, further supporting the hypotheses of clonal evolution and secondary transformation. Despite gross total resection, craniospinal irradiation, and chemotherapy, the patient developed rapid leptomeningeal dissemination and died 5 months after surgery. This case provides clinicopathological and molecular evidence for clonal evolution and secondary transformation of PXA into an RT. The presence of germline ATM mutation may have therapeutic and biological relevance. Further studies are required to clarify the pathogenesis and optimal management of these rare and aggressive tumors.
2.Korean Thyroid Association Guidelines on the Management of Differentiated Thyroid Cancers; Part II. Follow-up Surveillance after Initial Treatment 2026
Eun Kyung LEE ; Seung Heon KANG ; Bon Seok KOO ; Mijin KIM ; Min Joo KIM ; Bo Hyun KIM ; Ji Won KIM ; Dong Gyu NA ; Sohyun PARK ; Ji-In BANG ; Kyorim BACK ; Youngduk SEO ; Young-Ik SON ; Young Shin SONG ; Dong Yeob SHIN ; Jong-Hyuk AHN ; Hwa Young AHN ; So Won OH ; Ho-Ryun WON ; Won Sang YOO ; Min Kyoung LEE ; Sang-Woo LEE ; Jeongmin LEE ; Ji Ye LEE ; Dong-Jun LIM ; Ki-Wook CHUNG ; Ari CHONG ; Jin Hyang JUNG ; Sun Wook CHO ; Yoon Young CHO ; Chae Moon HONG ; Young Joo PARK ;
International Journal of Thyroidology 2026;19(1):1-40
In patients with differentiated thyroid cancer (DTC), initial recurrence risk stratification based on clinical, histopathological, and perioperative data remains the key determinant for guiding management strategies during the first 1-2 years post-treatment. However, the adoption of ongoing risk stratification (ORS), which dynamically reassesses risk by integrating longitudinal clinical data and treatment response, enables more precise long-term prognostic assessment and facilitates highly individualized management. Building upon recent guidelines, the 2026 KTA guideline has been further refined by incorporating robust evidence from large-scale national cohorts and comprehensive systematic reviews. These updated recommendations outline contemporary concepts of ORS, risk-adapted TSH suppression targets, optimized surveillance modalities for recurrence detection, and disease-specific long-term follow-up strategies. Reflecting the paradigm shift toward de-escalated treatment, this revision integrates evolved perspectives on TSH suppression intensity, the clinical interpretation of thyroglobulin levels, and tailored follow-up intervals. These evidence-based recommendations aim to minimize unnecessary treatment and excessive surveillance in the large proportion of patients with excellent prognosis after initial therapy, while ensuring that each patient receives appropriately tailored and effective long-term management.
3.Electrical Stimulation Using a Low-Frequency and Low-Intensity Alternating Current Modulates Type I Procollagen Production and MMP-1Expression in Dermal Fibroblasts
Bo Mi KANG ; Jung Min AHN ; Jieun KIM ; Kyungho PAIK ; Bo Ri KIM ; Dong Hun LEE ; Sang Woong YOUN ; Keun-Yong EOM ; Chong Won CHOI
Annals of Dermatology 2025;37(3):152-161
Background:
Despite various therapeutic modalities for keloids have been introduced; however, their therapeutic effects are limited. Therefore, the development of a new approach for inhibiting collagen production by scar fibroblasts is needed.
Objective:
To investigate the effect of electrical stimulation using a low-frequency and low-intensity alternating current on collagen and MMP-1 levels in human dermal fibroblasts.
Methods:
Low-frequency (20 kHz) and low-intensity (1 V/cm) electrical stimulations were applied to primary dermal fibroblasts. The production of type I procollagen and expression of matrix metalloproteinase-1 were evaluated. Transcriptomic analyses were conducted to explore the possible modes of action of electrical stimulation.
Results:
Electrical stimulation effectively suppressed type I procollagen production and increased MMP-1 expression. In addition, transcriptomic analyses revealed that electrical stimulation altered the gene expression associated with membrane permeability and the structure of cellular membranes. Validation using real-time polymerase chain reaction revealed that electrical stimulation significantly altered the expression of mechanosensitive ion channels (PIEZO2) and membrane-bound protein organizing caveolae (CAVIN2).
Conclusion
Electrical stimulation using low-frequency and low-intensity alternating currents effectively modulates extracellular matrix homeostasis by altering the cellular membrane structure and function. Our findings suggest a promising therapeutic approach for the management of keloids and hypertrophic scars.
4.The First Korean Case of MAN1B1-Congenital Disorder of Glycosylation Diagnosed Using Whole-Exome Sequencing and Matrix-Assisted Laser Desorption Ionization Time-of-Flight Mass Spectrometry
Kyoung Bo KIM ; Gi Su LEE ; Soyoung SHIN ; Dong-Chan KIM ; Donggun SEO ; Hyeongjin KWEON ; Hyein KANG ; Sunggyun PARK ; Do-Hoon KIM ; Namhee RYOO ; Soyoung LEE ; Jung Sook HA
Annals of Laboratory Medicine 2025;45(1):112-115
5.Unusual Metachronous Renal Pelvis and Colon Metastases in a Patient with Endometrial Cancer: A Case Report
Juin KIM ; Chul-min LEE ; Bo-Kyeong KANG ; Mimi KIM
Journal of the Korean Society of Radiology 2025;86(2):279-283
Endometrial cancer commonly metastasizes to the pelvic and para-aortic lymph nodes, vagina, peritoneum, and lungs. Unusual sites of metastasis include the bone, brain, abdominal wall, muscles, and intra-abdominal organs. To our knowledge, there have been no documented cases of synchronous or metachronous metastasis of endometrial cancer to the renal pelvis or colon. Metastatic tumors in the renal pelvis and colon indicate nonspecific radiological findings, making them difficult to distinguish from primary tumors. We describe a case of a 55-year-old female previously treated for endometrial cancer, who was subsequently found to have metastatic masses in the renal pelvis and colon. The two masses were initially misidentified as primary urothelial carcinoma and colon adenocarcinoma.
6.PDK4 expression and tumor aggressiveness in prostate cancer
Eun Hye LEE ; Yun-Sok HA ; Bo Hyun YOON ; Minji JEON ; Dong Jin PARK ; Jiyeon KIM ; Jun-Koo KANG ; Jae-Wook CHUNG ; Bum Soo KIM ; Seock Hwan CHOI ; Hyun Tae KIM ; Tae-Hwan KIM ; Eun Sang YOO ; Tae Gyun KWON
Investigative and Clinical Urology 2025;66(3):227-235
Purpose:
Prostate cancer ranks as the second most common cancer in men globally, representing a significant cause of cancer-related mortality. Metastasis, the spread of cancer cells from the primary site to distant organs, remains a major challenge in managing prostate cancer. Pyruvate dehydrogenase kinase 4 (PDK4) is implicated in the regulation of aerobic glycolysis, emerging as a potential player in various cancers. However, its role in prostate cancer remains unclear. This study aims to analyze PDK4 expression in prostate cancer cells and human samples, and to explore the gene's clinical significance.
Materials and Methods:
PDK4 expression was detected in cell lines and human tissue samples. Migration ability was analyzed using Matrigel-coated invasion chambers. Human samples were obtained from the Kyungpook National University Chilgok Hospital.
Results:
PDK4 expression was elevated in prostate cancer cell lines compared to normal prostate cells, with particularly high levels in DU145 and LnCap cell lines. PDK4 knockdown in these cell lines suppressed their invasion ability, indicating a potential role of PDK4 in prostate cancer metastasis. Furthermore, our results revealed alterations in epithelial-mesenchymal transition markers and downstream signaling molecules following PDK4 suppression, suggesting its involvement in the modulation of invasion-related pathways. Furthermore, PDK4 expression was increased in prostate cancer tissues, especially in castration-resistant prostate cancer, compared to normal prostate tissues, with PSA and PDK4 expression showing a significantly positive correlation.
Conclusions
PDK4 expression in prostate cancer is associated with tumor invasion and castration status. Further validation is needed to demonstrate its effectiveness as a therapeutic target.
7.Development of a Long-Acting Follicle-Stimulating Hormone Using Serum Albumin Fab-Associated Technology for Female Infertility
Daham KIM ; Yoon Hee CHO ; Min Jeong KANG ; So Jeong LEE ; Soohyun LEE ; Bo Hyon YUN ; Hyunjin CHI ; Jeongsuk AN ; Kyungsun LEE ; Jaekyu HAN ; Susan CHI ; Moo Young SONG ; Sang-Hoon CHA ; Eun Jig LEE
Endocrinology and Metabolism 2025;40(1):146-155
Background:
Recombinant human follicle-stimulating hormone (rhFSH) is commonly used to treat female infertility, but its short half-life necessitates multiple doses. Even corifollitropin alfa, with an extended half-life, requires supplementary injections of rhFSH after 7 days. This study aimed to develop and evaluate a long-acting follicle-stimulating hormone (FSH) formulation using anti-serum albumin Fab-associated (SAFA) technology to avoid additional injections and enhance ovarian function.
Methods:
SAFA-FSH was synthesized using a Chinese hamster ovary expression system. Its biological efficacy was confirmed through assays measuring its ability to stimulate cyclic adenosine monophosphate (cAMP) production, estradiol synthesis, and the expression of human cytochrome P450 family 19 subfamily A member 1 (hCYP19α1) and human steroidogenic acute regulatory protein (hSTAR) in human ovarian granulosa (KGN) cells. To evaluate the effects of SAFA-FSH, we compared its impact on serum estradiol levels and ovarian weight increase with that of rhFSH in Sprague-Dawley (SD) rats using the modified Steelman-Pohley test.
Results:
The results indicated that SAFA-FSH induces cAMP synthesis in KGN cells and upregulates the expression of hCYP19α1 and hSTAR in a dose-dependent manner. Female SD rats, aged 21 days, receiving daily subcutaneous human chorionic gonadotropin injections for 5 days exhibited a significant increase in serum estradiol levels and ovarian weight when administered SAFA-FSH on the first day or when given nine injections of rhFSH over 5 days. Notably, the group receiving SAFA-FSH on the first and third days demonstrated an even greater rise in serum estradiol levels and ovarian weight.
Conclusion
These findings suggest that SAFA-FSH presents a promising alternative to current rhFSH treatments for female infertility. However, further research is essential to thoroughly assess its safety and efficacy in clinical contexts.
8.Measuring Medical Waste from Gastrointestinal Endoscopies in South Korea to Estimate Their Carbon Footprint
Da Hyun JUNG ; Hyun Jung LEE ; Tae Joo JEON ; Young Sin CHO ; Bo Ra KANG ; Nae Sun YOUN ; Jae Myung CHA
Gut and Liver 2025;19(1):43-49
Background/Aims:
Although gastrointestinal endoscopy (GIE) is a major contributor to the carbon footprint of national healthcare, the amount of medical waste generated by GIE procedures is not reported in South Korea. This study aimed to measure the amount of medical waste generated from GIE procedures in South Korea.
Methods:
We conducted a 5-day audit of medical waste generated during GIEs at seven hospitals. During the study period, medical waste in the endoscopy examination rooms was measured twice daily and documented as mass (kg). To calculate the mean mass of disposable waste generated during one esophagogastroduodenoscopy (EGD) and one colonoscopy, the mean mass of medical waste generated from seven examinations was calculated. The mean mass of medical waste generated during GIEs was calculated by dividing the total mass of medical waste generated by the number of GIE procedures.
Results:
Overall, 3,922 endoscopies were performed and 4,558 kg of waste was generated. The mean weight of medical waste generated per endoscopy was 1.34 kg. Each EGD and colonoscopy generated a mean of 0.24 kg and 0.43 kg of disposable waste, respectively. Applying the mean waste estimates from this study to annual GIE procedures performed in South Korea in 2022 showed that the total medical waste produced from GIE was 13,704,453 kg. In addition, the total masses of medical waste produced during EGD and colonoscopy procedures were 819,766 kg and 2,889,478 kg, respectively.
Conclusions
Our quantitative measurement showed that a large amount of medical waste is generated from GIE procedures. However, further research is warranted to reduce medical waste generated during GIE, which is an urgent unmet need.
9.Development of a Long-Acting Follicle-Stimulating Hormone Using Serum Albumin Fab-Associated Technology for Female Infertility
Daham KIM ; Yoon Hee CHO ; Min Jeong KANG ; So Jeong LEE ; Soohyun LEE ; Bo Hyon YUN ; Hyunjin CHI ; Jeongsuk AN ; Kyungsun LEE ; Jaekyu HAN ; Susan CHI ; Moo Young SONG ; Sang-Hoon CHA ; Eun Jig LEE
Endocrinology and Metabolism 2025;40(1):146-155
Background:
Recombinant human follicle-stimulating hormone (rhFSH) is commonly used to treat female infertility, but its short half-life necessitates multiple doses. Even corifollitropin alfa, with an extended half-life, requires supplementary injections of rhFSH after 7 days. This study aimed to develop and evaluate a long-acting follicle-stimulating hormone (FSH) formulation using anti-serum albumin Fab-associated (SAFA) technology to avoid additional injections and enhance ovarian function.
Methods:
SAFA-FSH was synthesized using a Chinese hamster ovary expression system. Its biological efficacy was confirmed through assays measuring its ability to stimulate cyclic adenosine monophosphate (cAMP) production, estradiol synthesis, and the expression of human cytochrome P450 family 19 subfamily A member 1 (hCYP19α1) and human steroidogenic acute regulatory protein (hSTAR) in human ovarian granulosa (KGN) cells. To evaluate the effects of SAFA-FSH, we compared its impact on serum estradiol levels and ovarian weight increase with that of rhFSH in Sprague-Dawley (SD) rats using the modified Steelman-Pohley test.
Results:
The results indicated that SAFA-FSH induces cAMP synthesis in KGN cells and upregulates the expression of hCYP19α1 and hSTAR in a dose-dependent manner. Female SD rats, aged 21 days, receiving daily subcutaneous human chorionic gonadotropin injections for 5 days exhibited a significant increase in serum estradiol levels and ovarian weight when administered SAFA-FSH on the first day or when given nine injections of rhFSH over 5 days. Notably, the group receiving SAFA-FSH on the first and third days demonstrated an even greater rise in serum estradiol levels and ovarian weight.
Conclusion
These findings suggest that SAFA-FSH presents a promising alternative to current rhFSH treatments for female infertility. However, further research is essential to thoroughly assess its safety and efficacy in clinical contexts.
10.Measuring Medical Waste from Gastrointestinal Endoscopies in South Korea to Estimate Their Carbon Footprint
Da Hyun JUNG ; Hyun Jung LEE ; Tae Joo JEON ; Young Sin CHO ; Bo Ra KANG ; Nae Sun YOUN ; Jae Myung CHA
Gut and Liver 2025;19(1):43-49
Background/Aims:
Although gastrointestinal endoscopy (GIE) is a major contributor to the carbon footprint of national healthcare, the amount of medical waste generated by GIE procedures is not reported in South Korea. This study aimed to measure the amount of medical waste generated from GIE procedures in South Korea.
Methods:
We conducted a 5-day audit of medical waste generated during GIEs at seven hospitals. During the study period, medical waste in the endoscopy examination rooms was measured twice daily and documented as mass (kg). To calculate the mean mass of disposable waste generated during one esophagogastroduodenoscopy (EGD) and one colonoscopy, the mean mass of medical waste generated from seven examinations was calculated. The mean mass of medical waste generated during GIEs was calculated by dividing the total mass of medical waste generated by the number of GIE procedures.
Results:
Overall, 3,922 endoscopies were performed and 4,558 kg of waste was generated. The mean weight of medical waste generated per endoscopy was 1.34 kg. Each EGD and colonoscopy generated a mean of 0.24 kg and 0.43 kg of disposable waste, respectively. Applying the mean waste estimates from this study to annual GIE procedures performed in South Korea in 2022 showed that the total medical waste produced from GIE was 13,704,453 kg. In addition, the total masses of medical waste produced during EGD and colonoscopy procedures were 819,766 kg and 2,889,478 kg, respectively.
Conclusions
Our quantitative measurement showed that a large amount of medical waste is generated from GIE procedures. However, further research is warranted to reduce medical waste generated during GIE, which is an urgent unmet need.

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