• Journal of Yeungnam Medical Science
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• v.33 no.1
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• pp.37-39
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• 2016

Schwannomas are uncommon neoplasms arising from Schwann cells of the neural sheath. Gastrointestinal schwannomas are rare, accounting for 1% of all malignant gastrointestinal tumors. Colonoscopic biopsy with immunohistochemical (IHC) staining is useful for confirming this tumor. We report on a patient with schwannoma arising from the ascending colon, which was detected by colonoscopy and endoscopic submucosal dissection was attempted. A 41-year-old man presented with abdominal discomfort. The patient was diagnosed with a subepithelial tumor on colonoscopy. He underwent endoscopic submucosal dissection. Histopathology and IHC staining confirmed that the colonic lesion was a benign schwannoma. However, the resection margin was positive. Therefore, laparoscopic ileocolectomy was performed.

• Journal of Gastric Cancer
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• v.11 no.4
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• pp.225-229
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• 2011

Purpose: Laparoscopic wedge resection of gastric submucosal tumor may be difficult in case of the endophytic mass or the mass located unreachable area such as cardia, and intragastric approach can be useful. We would present the experiences of the intragastric wedge resection. Materials and Methods: There were 7 patients diagnosed as gastric submucosal tumor and underwent the intragastric wedge resection at Surgery, Chungnam National University Hospital. We reviewed medical record. Results: There were 3 male and 4 female. Mean age was 65 years-old (57~73). Mean body mass index was 26.28 kg/$m^2$ (21.28~35.30). Location of lesions was 4 cardia, 2 fundus and 1 midbody, respectively. Mean operation time was 83.6 minutes (70~105). All patients were healed without any complication. Mean postoperative hospital stay was 5.4 days (4~6). Mean size was 2.7 cm (2.3~3.8). Pathologic finding was 5 gastrointestinal stromal tumor and 2 leiomyoma. Conclusions: The single incision intragastric wedge resection of gastric submucosal tumor is feasible and acceptable, especially in mass of gastric upper part.

• Clinical Endoscopy
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• v.51 no.6
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• pp.527-533
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• 2018

There have been many advances in endoscopic imaging technologies. Magnifying endoscopy with narrow-band imaging is an innovative optical technology that enables the precise discrimination of structural changes on the mucosal surface. Several studies have demonstrated its usefulness and superiority for tumor detection and differential diagnosis in the stomach as compared with conventional endoscopy. Furthermore, magnifying endoscopy with narrow-band imaging has the potential to predict the invasion depth and tumor margins during gastric endoscopic submucosal dissection. Classifications of the findings of magnifying endoscopy with narrow-band imaging based on microvascular and pit patterns have been proposed and have shown excellent correlations with invasion depth confirmed by microscopy. In terms of tumor margin prediction, magnifying endoscopy with narrow-band imaging offers superior delineation of gastric tumor margins compared with traditional chromoendoscopy with indigo carmine. The limitations of narrow-band imaging, such as the need for considerable training, long procedure time, and lack of studies about its usefulness in undifferentiated cancer, should be resolved to confirm its value as a complementary method to endoscopic submucosal dissection. However, the role of magnifying endoscopy with narrow-band imaging is expected to increase steadily with the increasing use of endoscopic submucosal dissection for the treatment of gastric tumors.

• Journal of Digestive Cancer Research
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• v.10 no.1
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• pp.1-8
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• 2022

The incidence of gastric neuroendocrine tumors (NET) has been increased with the improvement of endoscopy accessibility. The World Health Organization classified NET of low (G1), intermediate (G2), high (G3) grade and neuroendocrine carcinoma with poor differentiation by mitotic count and Ki-67 labeling index. Gastric NET are divided into three subtypes based on the pathophysiology, and treatment is determined according to the subtype and prognostic factors of tumor. For diagnosis, endoscopy with biopsy, endoscopic ultrasonography, abdominal pelvis computed tomography, and serum gastrin level measure are required. In general, type 3, size > 2 cm, deep submucosal infiltration, high histological grade, lymphovascular invasion and metastasis are poor prognostic factors. Type 1 or 2 without these factors are treated by endoscopic resection, and other tumors needs surgery. Endoscopic resection of early type 3 or type 1 and 2 tumors with poor prognostic factors still remains a challenge.

• Journal of Gastric Cancer
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• v.19 no.4
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• pp.427-437
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• 2019

Purpose: We aimed to evaluate the clinical characteristics of microsatellite instability in early gastric cancer. Materials and Methods: The microsatellite instability status of resected early gastric tumors was evaluated using two mononucleotide repeat markers (BAT25 and BAT26) and three dinucleotide repeat markers (D5S346, D2S123, and D17S250). Tumors with instability in two or more markers were defined as microsatellite instability-high (MSI-H) and others were classified as microsatellite stable (MSS). Results: Overall, 1,156 tumors were included in the analysis, with 85 (7.4%) classified as MSI-H compared with MSS tumors. For MSI-H tumors, there was a significant correlation with the female sex, older age, tumor location in the lower gastric body, intestinal histology, lymphovascular invasion (LVI), and submucosal invasion (P<0.05). There was also a trend toward an association with lymph node (LN) metastasis (P=0.056). In mucosal gastric cancer, there was no significant difference in MSI status in tumors with LN metastasis or tumors with LVI. In submucosal gastric cancer, LVI was more frequently observed in MSI-H than in MSS tumors (38.9% vs. 25.0%, P=0.027), but there was no difference in the presence of LN metastases. The prognosis of MSI-H tumors was similar to that of MSS tumors (log-rank test, P=0.797, the hazard ratio for MSI-H was adjusted by age, sex, pT stage, and the number of metastatic LNs, 0.932; 95% confidence interval, 0.423-2.054; P=0.861). Conclusions: MSI status was not useful in predicting prognosis in early gastric cancer. However, the frequent presence of LVI in early MSI-H gastric cancer may help guide the appropriate treatment for patients, such as endoscopic treatment or limited LN surgical dissection.

• Journal of Gastric Cancer
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• v.21 no.2
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• pp.111-121
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• 2021

Laparoscopic endoscopic cooperative surgery (LECS) refers to the endoscopic dissection of the mucosal or submucosal layers with laparoscopic seromuscular resection. We recommend a treatment algorithm for the LECS procedure for gastric benign tumors according to the protruding type. In the exophytic type, endoscopic-assisted wedge resection can be performed. In the endophytic type, endoscopic-assisted wedge resection of the anterior wall is relatively easy to perform, and endoscopic-assisted transgastric resection, laparoscopic-assisted intragastric surgery, or single-incision intragastric resection in the posterior wall and esophagogastric junction (EG Jx) can be attempted. We propose an algorithm for the LECS procedure for early gastric cancer according to the tumor location. The endoscopic submucosal dissection (ESD) procedure can be adapted for all areas of the stomach, and single-incision ESD can be performed in the mid to high body and the EG Jx. In full-thickness gastric resection, laparoscopy-assisted endoscopic full-thickness resection can be adapted for the entire area of the stomach, but it cannot be applied to the pyloric and EG Jx. In conclusion, surgeons need to select the LECS procedure according to tumor type, tumor location, the surgeon's individual experience, and the situation of the institution while also considering the advantages and disadvantages of each procedure.

• Journal of Gastric Cancer
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• v.24 no.2
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• pp.199-209
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• 2024

Purpose: Long-term outcomes of patients with positive lateral margins (pLMs) after endoscopic submucosal dissection (ESD) for early gastric cancer (EGC). This study aimed to evaluate the remnant cancer and survival rates of patients with pLMs compared with those who underwent curative resection. Materials and Methods: A retrospective analysis was performed on consecutive patients with pLMs as the only non-curative factor of expanded indication who underwent ESD for EGC with a follow-up duration of 5 years or more. The rates of remnant cancer, recurrence, and survival were analyzed and compared to those of control patients who underwent curative resection by propensity score matching. Results: Among 3,515 patients treated with ESD between 2005 and 2018, 123 non-curative EGCs were retrospectively analyzed. A total of 108 patients were followed up without endoscopic or surgical resection for 8.2 years. The control group was matched in a 1:1 ratio with patients with EGC who underwent curative resection after ESD. The observation group with pLMs had a higher incidence of remnant cancer (25.9%; 28/108) compared to that in the curative resection group (0/108; P=0.000). The remaining tumors were treated with surgical or endoscopic resection, and no additional recurrences were observed. The overall survival analysis demonstrated no significant difference between the observation and curative resection groups (P=0.577). Conclusions: No difference was observed in the overall survival rate between observation and curative resection groups. Therefore, observation may be a possible option for incomplete ESD with pLMs if continuous follow-up is performed.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.13
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• pp.5371-5375
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• 2014

Background: An accurate assessment of potential lymph node metastasis is important for the appropriate treatment of early gastric cancers. Therefore, this study analyzed predictive factors associated with lymph node metastasis and identified differences between mucosal and submucosal gastric cancers. Materials and Methods: A total of 518 early gastric cancer patients who underwent radical gastrectomy were reviewed in this study. Clinicopathological features were analyzed to identify predictive factors for lymph node metastasis. Results: The rate of lymph node metastasis in early gastric cancer was 15.3% overall, 3.3% for mucosal cancer, and 23.5% for submucosal cancer. Using univariate analysis, risk factors for lymph node metastasis were identified as tumor location, tumor size, depth of tumor invasion, histological type and lymphovascular invasion. Multivariate analysis revealed that tumor size >2 cm, submucosal invasion, undifferentiated tumors and lymphovascular invasion were independent risk factors for lymph node metastasis. When the carcinomas were confined to the mucosal layer, tumor size showed a significant correlation with lymph node metastasis. On the other hand, histological type and lymphovascular invasion were associated with lymph node metastasis in submucosal carcinomas. Conclusions: Tumor size >2 cm, submucosal tumor, undifferentiated tumor and lymphovascular invasion are predictive factors for lymph node metastasis in early gastric cancer. Risk factors are quite different depending on depth of tumor invasion. Endoscopic treatment might be possible in highly selective cases.

• Journal of Yeungnam Medical Science
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• v.28 no.2
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• pp.165-172
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• 2011

Gastric glomus tumor is a rare mesenchymal tumor that originates from modified smooth muscle cells of the glomus body. Glomus tumors are commonly observed in peripheral soft tissue, such as dennis or subungal region, but rarely in the gastrointestinal tract. A 39-year-old woman was admitted due to epigastric soreness. Upper gastrointestinal endoscopy revealed a subepithelial mass measuring 3.5 cm with central ulceration at the lesser curvature-posterior wall of the antrum. Characteristically, contrast enhanced abdominal computed tomography scan demonstrated high enhancement of the submucosal mass up to the same level of the abdominal aorta in the arterial phase; this enhancement persisted to delayed phase. Due to the risk of bleeding and malignancy, wedge resection of the submucosal tumor was performed. Histologic findings were compatible with a glomus tumor.

• Journal of Gastric Cancer
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• v.11 no.3
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• pp.162-166
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• 2011

Purpose: Endoscopic resection is widely accepted as standard treatment for early gastric cancer (EGC) without lymph node metastasis. The procedure is minimally invasive, safe, and convenient. However, surgery is sometimes needed after endoscopic mucosal resection (EMR)/endoscopic submucosal dissection (ESD) due to perforation, bleeding, or incomplete resection. We evaluated the role of surgery after incomplete resection. Materials and Methods: We retrospectively studied 29 patients with gastric cancer who underwent a gastrectomy after incomplete EMR/ESD from 2006 to 2010 at Korea University Hospital. Results: There were 13 incomplete resection cases, seven bleeding cases, three metachronous lesion cases, three recurrence cases, two perforation cases, and one lymphatic invasion case. Among the incomplete resection cases, a positive vertical margin was found in 10, a positive lateral margin in two, and a positive vertical and lateral margin in one case. Most cases (9/13) were diagnosed as mucosal tumors by endoscopic ultrasonography, but only three cases were confirmed as mucosal tumors on final pathology. The positive residual tumor rate was two of 13. The lymph node metastasis rate was three of 13. All lymph node metastasis cases were submucosal tumors with positive lymphatic invasion and no residual tumor in the gastrectomy specimen. No cases of recurrence were observed after curative resection. Conclusions: A gastrectomy is required for patients with incomplete resection following EMR/ESD due to the risk of residual tumor and lymph node metastasis.