AOM/DSS 유발 대장암에 대한 楡根皮와 白花蛇舌草 단일 및 배합 추출물의 항암 및 항염 효과

이선아,백동기,문구 대한한방내과학회 2017 大韓韓方內科學會誌 Vol.38 No.6

Objectives: The aim of this experimental study was to evaluate the anti-neoplastic and anti-inflammatory effects of single and mixed extracts of Ulmus davidiana (UD) and Oldenlandia diffusa (OD) on azoxymethane/dextran sodium sulfate (AOM/DSS)-induced colonic neoplasms in mice. Methods: AOM/DSS induces colitis-associated colonic neoplasms in mice. Mice were divided into seven groups: normal-no inducement and no treatment; control-colonic neoplasms with no treatment; UD-colonic neoplasms and treatment with UD; OD-colonic neoplasms and treatment with OD; UD1+OD1-colonic neoplasms and treatment with UD1 and OD1. UD1+OD2-colonic neoplasms and treatment with UD1 and OD2; UD2+OD1-colonic neoplasms and treatment with UD2 and OD1. Single and mixed preparations of UD and OD were applied to mice for six weeks. The colon length and weight and histopathologic changes of colon tissue were observed. Serum pro-inflammatory cytokines, including tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6), were determined by enzyme-linked immunosorbent assay. The mRNA expression levels of Bax, Bcl-2, and interferon-gamma (INF-γ) were measured by RT-PCR. Results: The colon length was significantly increased in OD, UD1+OD2, and UD2+OD1 mice, and the colon weight was significantly decreased in OD and UD1+OD2 mice. The morphological change of colon epithelial cells was more suppressed in complex-treatment groups than in single-treatment groups. The inhibitory effect on inflammatory cell invasion was especially shown in UD1+OD2 mice. The serum level of the pro-inflammatory TNF-α was decreased in all complex-treatment groups, and the IL-6 level was decreased in UD1+OD1 mice. Single-treatment groups had an increase in the mRNA expression of the pro-apoptosis regulator Bax, and UD2+OD1 decreased the mRNA expression of the anti-apoptosis regulator Bcl-2. The mRNA expression of INF-γ associated with inflammation was decreased in OD and UD1+OD2 mice. Conclusions: This study suggests that single and mixed extracts of Ulmus davidiana and Oldenlandia diffusa have anti-neoplastic and anti-inflammatory effects on AOM/DSS-induced colonic neoplasms in mice. Therefore, we conclude that UD, OD, and a mixture of UD and OD are potential therapeutic agents for colitis-associated colonic neoplasms.

Risk Factors for Metachronous Gastric Neoplasms in Patients Who Underwent Endoscopic Resection of a Gastric Neoplasm

( Hyuk Yoon ),( Nayoung Kim ),( Cheol Min Shin ),( Hye Seung Lee ),( Bo Kyoung Kim ),( Gyeong Hoon Kang ),( Jung Mogg Kim ),( Joo Sung Kim ),( Dong Ho Lee ),( Hyun Chae Jung ) 대한소화기학회 2016 Gut and Liver Vol.10 No.2

Background/Aims: To identify the risk factors for metachronous gastric neoplasms in patients who underwent an endoscopic resection of a gastric neoplasm. Methods: We prospectively collected clinicopathologic data and measured the methylation levels of HAND1, THBD, APC, and MOS in the gastric mucosa by methylation-specific real-time polymerase chain reaction in patients who underwent endoscopic resection of gastric neoplasms. Results: A total of 257 patients with gastric neoplasms (113 low-grade dysplasias, 25 highgrade dysplasias, and 119 early gastric cancers) were enrolled. Metachronous gastric neoplasm developed in 7.4% of patients during a mean follow-up of 52 months. The 5-year cumulative incidence of metachronous gastric neoplasm was 4.8%. Multivariate analysis showed that moderate/severe corpus intestinal metaplasia and family history of gastric cancer were independent risk factors for metachronous gastric neoplasm development; the hazard ratios were 4.12 (95% confidence interval [CI], 1.23 to 13.87; p=0.022) and 3.52 (95% CI, 1.09 to 11.40; p=0.036), respectively. The methylation level of MOS was significantly elevated in patients with metachronous gastric neoplasms compared age- and sexmatched patients without metachronous gastric neoplasms (p=0.020). Conclusions: In patients who underwent endoscopic resection of gastric neoplasms, moderate/severe corpus intestinal metaplasia and a family history of gastric cancer were independent risk factors for metachronous gastric neoplasm, and MOS was significantly hypermethylated in patients with metachronous gastric neoplasms. (Gut Liver 2016;10:228-236)

Pathologic characteristics of histiocytic and dendritic cell neoplasms

Sun Och Yoon 대한혈액학회 2024 Blood Research Vol.59 No.2

Histiocytic and dendritic cell neoplasms comprise diverse tumors originating from the mononuclear phagocytic system, which includes monocytes, macrophages, and dendritic cells. The 5th edition of the World Health Organization (WHO) classification updating the categorization of these tumors, reflecting a deeper understanding of their pathogenesis. In this updated classification system, tumors are categorized as Langerhans cell and other dendritic cell neoplasms, histiocyte/macrophage neoplasms, and plasmacytoid dendritic cell neoplasms. Follicular dendritic cell neoplasms are classified as mesenchymal dendritic cell neoplasms within the stroma-derived neoplasms of lymphoid tissues. Each subtype of histiocytic and dendritic cell neoplasms exhibits distinct morphological characteristics. They also show a characteristic immunophenotypic profile marked by various markers such as CD1a, CD207/langerin, S100, CD68, CD163, CD4, CD123, CD21, CD23, CD35, and ALK, and hematolymphoid markers such as CD45 and CD43. In situ hybridization for EBV-encoded small RNA (EBER) identifies a particular subtype. Immunoprofiling plays a critical role in determining the cell of origin and identifying the specific subtype of tumors. There are frequent genomic alterations in these neoplasms, especially in the mitogen-activated protein kinase pathway, including BRAF (notably BRAF V600E), MAP2K1, KRAS, and NRAS mutations, and ALK gene translocation. This review aims to offer a comprehensive and updated overview of histiocytic and dendritic cell neoplasms, focusing on their ontogeny, morphological aspects, immunophenotypic profiles, and molecular genetics. This comprehensive approach is essential for accurately differentiating and classifying neoplasms according to the updated WHO classification.

무증상 한국인에서 대장 종양의 유병률 및 대장암 선별검사로서 대장내시경 검사의 역할

장혜숙 ( Hye Sook Chang ),최재원 ( Jae Won Choe ),양석균 ( Suk Kyun Yang ),명승재 ( Seung Jae Myung ),정훈용 ( Hwoon Yong Jung ),이진혁 ( Gin Hyug Lee ),홍원선 ( Weon Seon Hong ),김진호 ( Jin Ho Kim ),민영일 ( Young Il Min ) 대한장연구학회 2003 Intestinal Research Vol.1 No.2

목적: 최근 대장암의 선별검사로서 대장내시경 검사의 중요성이 강조되고 있으나, 이에 대한 국내 연구는 미비하다. 저자들은 무증상 한국인에서 대장 종양의 유병률을 알아보고, 대장암의 선별검사로서 대장내시경 검사의 역할에 대해 알아보고자 하였다. 대상 및 방법: 1998년 3월부터 2002년 7월까지 서울아산병원 건강증진센터에서 대장내시경 검사를 시행받은 3,325명의 검진자 중 직장 출혈, 최근 배변 습관의 변화, 대장암 또는 용종의 가족력이나 과거력, 염증성 장질환이나 대장 수술의 과거력 및 지난 10년 이내에 대장 내시경 검사나 대장조영술을 시행받은 적이 있는 환자 1,106명 및 대장내시경 검사가 불완전하게 시행된 11명을 제외한 2,208명을 대상으로 대장 종양의 빈도와 특성을 분석하였다. 결과: 대상군의 평균 나이는 49.2±10.1세였으며, 남자가 1,564명(70.8%)이었다. 대장 종양의 유병률은 선종 18.3%, 진행성 선종 2.0%, 대장암 0.3%이었으며, 50세 이상의 경우에는 각각 25.8%, 3.0%, 0.5%이었다. 남녀 모두 연령이 증가할수록 대장 선종, 진행성 선종 및 대장암의 빈도가 증가하였으며(p for trend<0.05), 여자보다 남자에서 대장 선종의 유병률이 유의하게 높았다(21.0% vs 12.0%, p<0.001). 한편 근위부 대장에서 종양이 발견될 확률은 원위부 대장에 종양이 있는 경우 26.0% (53/2004)로서 원위부 대장에 종양이 없는 경우의 10.3% (207/2004)보다 유의하게 높았다(p<0.001). 그러나 근위부 대장에서 관찰되는 진행성 종양의 69.2% (18/26)가 원위부 대장에 이상이 없이 고립성으로 존재한 경우였다. 결론: 무증상 한국인에서 대장 종양의 유병률은 서양에 비해 다소 낮은 경향이 있으며 또한 남녀 사이에 차이를 보인다. 따라서 한국에서의 대장암 선별검사의 지침을 마련하는데 있어 이러한 점들이 고려되어야 할 것이다. 한편 원위부 대장에 종양이 있는 경우에는 그렇지 않은 경우에 비해 근위부 대장에서 종양이 발견될 확률이 높아지지만, 원위부 대장에 종양이 있는 경우에만 대장내시경 검사를 할 경우 근위부 진행성 종양의 약 2/3를 놓치게 된다. 따라서 대장암 선별 검사로서 대장내시경 검사는 매우 유용한 것으로 생각된다. Background/Aims: Recent studies have reported the importance of screening colonoscopy for colorectal cancer. However, the prevalence of colorectal neoplasms in asymptomatic Korean population has not been determined until now. The purpose of this study was to evaluate the prevalence of colorectal neoplasms in asymptomatic Korean population and to assess the role of colonoscopy in colorectal cancer screening. Methods: We reviewed the endoscopic and pathologic reports of 3,325 patients who underwent colonoscopy at the Health Promotion Center, Asan Medical Center, from 1998 to 2002. Of them, 2,208 asymptomatic patients who underwent colonoscopy for the purpose of colorectal cancer screening were enrolled. Results: The mean age was 49.2 years and 70.8% were men. The overall prevalence of colorectal neoplasms was 18.6% and the prevalence among patients 50 years of age or older was 26.3%. The prevalence of neoplasms increased with age and was higher in the male. Patients with distal neoplasms were more likely to have proximal neoplasms than those without distal neoplasms. However, 69.2% of the patients with advanced proximal neolplasms had no synchronous distal neoplasms. Conclusions: The prevalence of colorectal neoplasms in asymptomatic average-risk Koreans seems to be lower than that in corresponding Westerns and shows a gender-difference. These results should be considered when establishing a guideline for colorectal cancer screening in Korea. Over half of the patients with advanced proximal neoplasms will not be detected if only those with distal neoplasms undergo colonoscopic screening. Therefore, colonoscopy may be useful as a screening test for colorectal cancer. (Intestinal Research 2003;2:179-185)

검색용 MeSH 필터와 단어인접탐색 기법을 활용한 KoreaMed 검색 효율성 향상 연구

정소나(So-Na Jeong),정지나(Ji-Na Jeong) 한국산학기술학회 2017 한국산학기술학회논문지 Vol.18 No.5

의학학술문헌에는 해부학적 조직이나 기관명이 종양, 질환 또는 감염 용어들과 서로 조합하여 사용되는 언어적 특성을 가지고 있다. 의학학술문헌을 검색할 때 데이터베이스가 제공하는 통제어휘도구인 Medical Subject Headings (MeSH)를 활용하면 합성어, 동의어, 그리고 관련어를 추가로 검색할 수 있어 검색효율이 높다. 본 연구에서는 위암(Stomach Neoplasms) 어휘군을 검색용 필터로 추가하는 방법과 동시출현용어의 거리를 측정하여 단어인접탐색 기법으로 검색효율성을 향상시키는 연구를 수행하였다. 검색용 MeSH에 추가할 어휘군을 결정하기 위해 실험데이터로 PubMed에서 중심주제어가 “Stomach Neoplasms”인 2007년∼2016년 논문 8,625편을 내려 받아 논문제목으로부터 Stomach와 Neoplasms 관련 용어의 동시출현여부를 분석하였다. 검색효율성은 KoreaMed에서 검색되는 MEDLINE 학술지를 대상으로 “Stomach Neoplasms”가 MeSH로 색인되어 있는 277편으로 검증하였는데 MEDLINE MeSH, MeSH on Demand, 그리고 KoreaMed MeSH Indexer의 “Stomach Neoplasms” 색인어 추출여부와 검색용 필터로 어휘군을 적용했을 때, 그리고 동시출현 용어의 단어인접검색 기법을 적용했을 때 “Stomach Neoplasms”의 매칭여부를 비교하였다. 가장 출현빈도가 높은 용어는 “Gastric Cancer”로 2,780회 출현하였다. “Gastric Adenocarcinoma”, “Gastric MALT Lymphoma” 등과 같이 “Stomach” 용어와 “Neoplasms" 관련 조직학적 용어가 조합된 경우는 7,376개(88.51%)였다. 동시출현 거리가 2단어인 용어는 “Stomach”와 “Neoplasms”의 합성어로 5,234개(70.95%)였다. 연구 결과 MeSH용어를 제외하고 973개의 용어를 후보어휘군으로 선정하였다. MEDLINE MeSH와 KoreaMed MeSH Indexer의 MeSH 매칭률은 209편(75.5%)이었는데 검색필터를 적용한 결과 263편(94.9%)으로, 동시출현 용어의 13단어 단어인접탐색 기법을 적용한 경우 268편(96.7%)으로 매칭률이 향상되었다. 본 연구를 통해 자연어 검색에 있어서 검색효율을 향상시키는 수단으로 검색용 시소러스를 사용하면 색인비용에 대한 부담이 적고, 통제어의 망라적 장점과 자연어가 가지는 용어의 특정성을 유지할 수 있음을 증명하였다. 또한 불리안 검색보다는 단어인접탐색 기법을 활용하면 정확률을 높일 수 있어 검색 효율성이 향상됨을 알 수 있었다. This study examined the method for adding related to “stomach neoplasms” as filters to the Medical Subject Headings (MeSH) for search as well as a method for improving the search efficiency through a word-proximity search by measuring the distance of co-occurring terms. A total of 8,625 articles published between 2007 and 2016 with the major topic terms “stomach neoplasms” were downloaded from PubMed article titles. The vocabulary to be added to the MeSH for search were analyzed. The search efficiency was verified by 277 articles that had “Stomach Neoplasms” indexed as MEDLINE MeSH in KoreaMed. As a result, 973 terms were selected as the candidate vocabulary. “Gastric Cancer” (2,780 appearances) was the most frequent term and 7,376 compound words (88.51%) combined the histological terms of “stomach” and “neoplasm”, such as “gastric adenocarcinoma” and “gastric MALT lymphoma”. A total of 5,234 compounds words (70.95%), in which the co-occurring distance was two words, were found. The matching rate through the MEDLINE MeSH and KoreaMed MeSH Indexer was 209 articles (75.5%). The search efficiency improved to 263 articles (94.9%) when the search filters were added, and to 268 articles (96.7%) when the 13 word-proximity search technique of the co-occurring terms was applied. This study showed that the use of a thesaurus as a means of improving the search efficiency in a natural language search could maintain the advantages of controlled vocabulary. The search accuracy can be improved using the word-proximity search instead of a Boolean search.

한공성 종양 43예의 임상 및 병리조직학적 고찰; 단일 기관에서의 경험

신현태 ( Hyun Tae Shin ),김준환 ( Jun Hwan Kim ),박세원 ( Se Won Park ),이경태 ( Kyung Tae Lee ),박지혜 ( Ji Hye Park ),이종희 ( Jong Hee Lee ),이동윤 ( Dong Youn Lee ),이주흥 ( Joo Heung Lee ),양준모 ( Jun Mo Yang ) 대한피부과학회 2012 大韓皮膚科學會誌 Vol.50 No.4

Background: Poroid neoplasms consist of classic poroma, hidroacanthoma simplex, dermal duct tumor, and poroid hidradenoma. Poroid neoplasms are not rare tumors in dermatology. However, studies of the clinicopathologic characteristics of poroid neoplasms in Korea are very limited. Objective: To investigate the clinicopathologic characteristics of poroid neoplasms in Korea. Methods: The clinicopathologic characteristics of forty three cases of poroid neoplasms were retrospectively analyzed. Results: Poroid neoplasms were diagnosed mostly in the sixth decade, without sex predominance. The most common site was the lower extremities, followed by the head & neck, the trunk, the sole, the palm, and the upper extremities. All cases were observed as a solitary lesion. Papule or nodule shape, verrucous surface, and erythmatous color were most common characteristics of poroid neoplasms. The two cases showed sebaceous differentiation. Some cases showed melanin pigmentations in the lesions or perilesional basal layer. Conclusion: Our study will be a resourceful data of poroid neoplasms for dermatologists and pathologists. (Korean J Dermatol 2012;50(4):313∼319)

Clinicopathological characteristics of synchronous and metachronous gastric neoplasms after endoscopic submucosal dissection

( Mi Young Jang ),( Jin Woong Cho ),( Wang Guk Oh ),( Sung Jun Ko ),( Shang Hoon Han ),( Hoon Ki Baek ),( Young Jae Lee ),( Ji Woong Kim ),( Gum Mo Jung ),( Yong Keun Cho ) 대한내과학회 2013 The Korean Journal of Internal Medicine Vol.28 No.6

Background/Aims: Endoscopic submucosal dissection (ESD) has become accepted as a minimally invasive treatment for gastric neoplasms. However, the development of synchronous or metachronous gastric lesions after endoscopic resection has become a major problem. We investigated the characteristics of multiple gastric neoplasms in patients with early gastric cancer (EGC) or gastric adenoma after ESD. Methods: In total, 512 patients with EGC or gastric adenoma who had undergone ESD between January 2008 and December 2011 participated in this study. The incidence of and factors associated with synchronous and metachronous gastric tumors were investigated in this retrospective study. Results: In total, 66 patients (12.9%) had synchronous lesions, and 13 patients (2.5%) had metachronous lesions. Older (> 65 years) subjects had an increased risk of multiple gastric neoplasms (p = 0.012). About two-thirds of the multiple lesions were similar in macroscopic and histological type to the primary lesions. The median interval from the initial lesions to the diagnosis of metachronous lesions was 31 months. The annual incidence rate of metachronous lesions was approximately 3%. Conclusions: We recommend careful follow-up in patients of advanced age (> 65 years) after initial ESD because multiple lesions could be detected in the remnant stomach. Annual surveillance might aid in the detection of metachronous lesions. Large-scale, multicenter, and longer prospective studies of appropriate surveillance programs are needed.

Colorectal Neoplasm in Asymptomatic Average-risk Koreans: The KASID Prospective Multicenter Colonoscopy Survey

( Hye Won Park ),( Jeong Sik Byeon ),( Suk Kyun Yang ),( Hyun Soo Kim ),( Won Ho Kim ),( Tae Il Kim ),( Dong Il Park ),( Young Ho Kim ),( Hyo Jong Kim ),( Moon Sung Lee ),( Il Kwon Chung ),( Sung Ae J 대한소화기기능성질환·운동학회 2009 Gut and Liver Vol.3 No.1

Background/Aims: The incidence of colorectal cancer is increasing in Korea, but the epidemiology of colorectal neoplasm is not clearly defined. We aimed to elucidate the prevalence of colorectal neoplasm in average-risk Koreans and explore the underlying risk factors. Methods: A large-scale, multicenter, prospective study was conducted. Of the 19,460 subjects who underwent colonoscopy at 11 university hospitals, we analyzed 3,951 consecutive asymptomatic adults with no risk factors for colorectal cancer. Results: The subjects were aged 52.1±11.6 years (mean±SD) and 60.1% of them were men. The prevalences of colorectal neoplasm and advanced neoplasm were 33.3% and 2.2%, respectively. The prevalence of a neoplasm increased with age (trend: p<0.001) and was higher in males (p<0.001). The prevalence of a proximal neoplasm was higher in subjects with a distal neoplasm than in those without a distal neoplasm (11.9% vs. 5.4%, p<0.001). However, 150 (52.1%) of the 288 subjects with a proximal neoplasm had no distal neoplasm. Conclusions: The overall prevalence of colorectal neoplasm in asymptomatic average-risk Koreans is comparable with that in Western countries. Being male and older are associated with a higher risk of colorectal neoplasm. Over half of proximal neoplasms are not associated with any distal sentinel lesions. (Gut and Liver 2009;3:35-40)

Aberrant DNA Methylation Maker for Predicting Metachronous Recurrence After Endoscopic Resection of Gastric Neoplasms

신철민,김나영,윤혁,최윤진,박지현,박영수,이동호 대한암학회 2022 Cancer Research and Treatment Vol.54 No.4

Purpose This study aimed to investigate whether MOS methylation can be useful for the prediction of metachronous recurrence after endoscopic resection of gastric neoplasms. Materials and Methods From 2012 to 2017, 294 patients were prospectively enrolled after endoscopic resection of gastric dysplasia (n=171) or early gastric cancer (n=123). When Helicobacter pylori was positive, eradication therapy was performed. Among them, 124 patients completed the study protocol (follow-up duration > 3 years or development of metachronous recurrence during the follow-up). Methylation levels of MOS were measured at baseline using quantitative MethyLight assay from the antrum. Results Median follow-up duration was 49.9 months. MOS methylation levels at baseline were not different by age, sex, and current H. pylori infection, but they showed a weak correlation with operative link on gastritis assessment (OLGA) or operative link on gastric intestinal metaplasia assessment (OLGIM) stages (Spearman’s ρ=0.240 and 0.174, respectively; p < 0.05). During the follow-up, a total of 20 metachronous gastric neoplasms (13 adenomas and 7 adenocarcinomas) were developed. Either OLGA or OLGIM stage was not useful in predicting the risk for metachronous recurrence. In contrast, MOS methylation high group (≥ 34.82%) had a significantly increased risk for metachronous recurrence compared to MOS methylation low group (adjusted hazard ratio, 4.76; 95% confidence interval, 1.54 to 14.79; p=0.007). Conclusion MOS methylation can be a promising marker for predicting metachronous recurrence after endoscopic resection of gastric neoplasms. To confirm the usefulness of MOS methylation, validation studies are warranted in the future (ClinicalTrials No. NCT04830618). Purpose This study aimed to investigate whether <i>MOS</i> methylation can be useful for the prediction of metachronous recurrence after endoscopic resection of gastric neoplasms.Materials and Methods From 2012 to 2017, 294 patients were prospectively enrolled after endoscopic resection of gastric dysplasia (n=171) or early gastric cancer (n=123). When <i>Helicobacter pylori</i> was positive, eradication therapy was performed. Among them, 124 patients completed the study protocol (follow-up duration > 3 years or development of metachronous recurrence during the follow-up). Methylation levels of <i>MOS</i> were measured at baseline using quantitative MethyLight assay from the antrum.Results Median follow-up duration was 49.9 months. <i>MOS</i> methylation levels at baseline were not different by age, sex, and current <i>H. pylorii</i> infection, but they showed a weak correlation with operative link on gastritis assessment (OLGA) or operative link on gastric intestinal metaplasia assessment (OLGIM) stages (Spearman’s ρ=0.240 and 0.174, respectively; p < 0.05). During the follow-up, a total of 20 metachronous gastric neoplasms (13 adenomas and 7 adenocarcinomas) were developed. Either OLGA or OLGIM stage was not useful in predicting the risk for metachronous recurrence. In contrast, <i>MOS</i> methylation high group (≥ 34.82%) had a significantly increased risk for metachronous recurrence compared to <i>MOS</i> methylation low group (adjusted hazard ratio, 4.76; 95% confidence interval, 1.54 to 14.79; p=0.007).Conclusion <i>MOS</i> methylation can be a promising marker for predicting metachronous recurrence after endoscopic resection of gastric neoplasms. To confirm the usefulness of <i>MOS</i> methylation, validation studies are warranted in the future (ClinicalTrials No. NCT04830618).

The Continuing Value of Ultrastructural Observation in Central Nervous System Neoplasms in Children

김나래,박성혜 대한병리학회 2015 Journal of Pathology and Translational Medicine Vol.49 No.6

Central nervous system (CNS) neoplasms are the second most common childhood malignancy after leukemia and the most common solid organ neoplasm in children. Diagnostic dilemmas with small specimens from CNS neoplasms are often the result of multifactorial etiologies such as frozen or fixation artifact, biopsy size, or lack of knowledge about rare or unfamiliar entities. Since the late 1950s, ultrastructural examination has been used in the diagnosis of CNS neoplasms, though it has largely been replaced by immunohistochemical and molecular cytogenetic studies. Nowadays, pathologic diagnosis of CNS neoplasms is achieved through intraoperative cytology, light microscopy, immunohistochemistry, and molecular cytogenetic results. However, the utility of electron microscopy (EM) in the final diagnosis of CNS neoplasms and investigation of its pathogenetic origin remains critical. Here, we reviewed the distinguishing ultrastructural features of pediatric CNS neoplasms and emphasize the continuing value of EM in the diagnosis of CNS neoplasms.