• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.43 no.2
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• pp.120-124
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• 2017

Osteonecrosis of the jaw (ONJ) is commonly described as an adverse effect of the use of bisphosphonates. A few cases of ONJ associated with tyrosine kinase inhibitors (sunitinib, imatinib) have been reported in the literature and usually they occurred in patients simultaneously treated with bisphosphonates. We report an atypical case of ONJ related only to imatinib. A 72-year-old male patient was treated with imatinib for metastases from gastrointestinal stromal tumors (GISTs). The patient developed ONJ after 22 months of imatinib only therapy. During his whole life, the patient had never been treated with bisphosphonates or radiotherapy. Microscope examination of the tissues confirmed the clinical diagnosis of diffuse osteonecrosis and showed absence of neoplastic cells. Thus, secondary localisations from GISTs were ruled out. Osteonecrosis of the lower jaw appeared 22 months after initial and exclusive therapy with imatinib. Therefore, imatinib monotherapy can induce ONJ in patients that have never been treated with bisphosphonates or radiotherapy.

• Journal of Gastric Cancer
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• v.18 no.4
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• pp.328-338
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• 2018

The incidence of gastroesophageal junction adenocarcinoma (GEJAC) in Western countries has increased in recent decades, in addition to a rise in the incidence of esophageal adenocarcinoma (EAC). Gastroesophageal reflux disease (GERD), obesity, smoking, alcohol consumption, and low Helicobacter pylori (HP) infection rate have been nominated as risk factors for such cancers. Among these risk factors, the increased prevalence of GERD and obesity and the decreased prevalence of HP infection are of special interest owing to the currently increasing prevalence of GEJAC in Western countries. Although similar trends in the prevalence of GERD, obesity, and HP infection are observed in Asian countries after a time lag from Western countries, it is still uncertain if the prevalence of GEJAC in Asian countries is increasing, especially in Korea. The incidence of GERD in Korea is currently increasing; it was below 3% in the 1990s. The incidence of obesity in the Korean population is increasing owing to the adoption of westernized lifestyles, including food preferences, and the HP infection rate in Korea is known to be decreasing. Therefore, based on logical extrapolation of observations of Western countries, the incidence of GEJAC will increase in Korea. However, the proportion of GEJAC among other upper gastrointestinal malignancies in Korea appears to be currently unchanged compared with that in the 1990s. Presently, there is a lack of epidemiologic studies on this issue in this region; therefore, more studies are needed to clarify the characteristics of these tumors and to improve clinical outcomes for patients with these tumors.

• Korean journal of aerospace and environmental medicine
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• v.30 no.2
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• pp.51-53
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• 2020

In commemoration of Vol. 30, Issue 2, our journal prepared three review articles, two original papers, and a case report. The first review analyzed aircraft accidents caused by pilots' fatigue and presented a protocol to measure their fatigue, such as primary background survey, subjective drowsiness/arousal evaluation, sleep and activity log, sleep data, and performance measurement. The second review analyzed shift work patterns and work characteristics that may affect the fatigue of aviation mechanics. Also, desirable work principles for aviation mechanics (restrictions on working hours, appropriate rest hours, and night shift restrictions) were presented. The third review discussed the effects that allergic rhinitis can have on pilots (drowsiness and decreased arousal) and introduced a safe treatment method that can prevent these adverse effects. In the first original article, the ratio of 'incompatible (non-fit)' result in aerospace medical examination among Korean aircraft pilots for the past five years was investigated by age group and the common causes of nonconformity were analyzed. In the second original article, the prevalence, mortality, prevalence according to age groups, and regional characteristics of severe febrile thrombocytopenia syndrome were compared and analyzed in Korea and Japan for the past five years. Finally, in the case report, the cases of a patient diagnosed as gastrointestinal stromal tumors who received surgical treatment and chemotherapy were discussed, and the results of the judgment were presented.

• Journal of Gastric Cancer
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• v.8 no.2
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• pp.104-109
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• 2008

Purpose: To investigate the clinicopathlogical characteristics and the surgical methods for gastric submucosal tumors in Korea, the Information Committee of the Korean Gastric Cancer Association performed a nationwide survey. Materials and Methods: Data on 878 patients who underwent resection from 2005 to 2006 were collected from medical records obtained from 47 institutes. Diagnosis, demographics, symptoms, tumor factors (location, size, degree of malignancy) and operative factors (surgicalmethod and approach, mortality) were analyzed. Results: Gastrointestinal stromal tumors (GISTs) were the most common cancers (n=586, 66.8%), followed by leiomyomas (n=97, 11.1%), schwannomas (n=70, 8.0%), ectopic pancreas (n=67, 7.8%) and carcinoids (n=16, 1.8%). The mean age of patients was 56.0 years and the male to female ratio was 1:1.18. Only 40.9% of the patients had symptoms at the time of diagnosis, such as abdominal pain, dyspepsia and bleeding. Gastric submucosal tumors were most frequently located in the upper third of the stomach and 55.4% of the GISTs (n=319) and 84.5% of the leiomyomas (n=84.5%) were located in the upper third of the stomach. Wedge resection (n=726, 82.8%) was the most common operative method, and laparoscopic surgery was performed in 388 patients (44.2%). Only one patient (0.1%) died within 30 days of surgery. A total of 115 patients withGISTs (21.1%, 115/544) had a high risk of malignancy and 41 patients (8.3%, 45/495) received adjuvant imatinib mesylate therapy. Conclusion: The survey showed that about two-thirds of the patients with a gastric submuscoal tumor (SMT) had a GIST, and about one-half of the patients underwent laparoscopic resection. These data presented in the nationwide survey could be used as a fundamental resource for gastric submucosal tumors in Korea.

• Korean Journal of Radiology
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• v.22 no.3
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• pp.344-353
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• 2021

Objective: The mitotic count of gastrointestinal stromal tumors (GIST) is closely associated with the risk of planting and metastasis. The purpose of this study was to develop a predictive model for the mitotic index of local primary GIST, based on deep learning algorithm. Materials and Methods: Abdominal contrast-enhanced CT images of 148 pathologically confirmed GIST cases were retrospectively collected for the development of a deep learning classification algorithm. The areas of GIST masses on the CT images were retrospectively labelled by an experienced radiologist. The postoperative pathological mitotic count was considered as the gold standard (high mitotic count, > 5/50 high-power fields [HPFs]; low mitotic count, ≤ 5/50 HPFs). A binary classification model was trained on the basis of the VGG16 convolutional neural network, using the CT images with the training set (n = 108), validation set (n = 20), and the test set (n = 20). The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated at both, the image level and the patient level. The receiver operating characteristic curves were generated on the basis of the model prediction results and the area under curves (AUCs) were calculated. The risk categories of the tumors were predicted according to the Armed Forces Institute of Pathology criteria. Results: At the image level, the classification prediction results of the mitotic counts in the test cohort were as follows: sensitivity 85.7% (95% confidence interval [CI]: 0.834-0.877), specificity 67.5% (95% CI: 0.636-0.712), PPV 82.1% (95% CI: 0.797-0.843), NPV 73.0% (95% CI: 0.691-0.766), and AUC 0.771 (95% CI: 0.750-0.791). At the patient level, the classification prediction results in the test cohort were as follows: sensitivity 90.0% (95% CI: 0.541-0.995), specificity 70.0% (95% CI: 0.354-0.919), PPV 75.0% (95% CI: 0.428-0.933), NPV 87.5% (95% CI: 0.467-0.993), and AUC 0.800 (95% CI: 0.563-0.943). Conclusion: We developed and preliminarily verified the GIST mitotic count binary prediction model, based on the VGG convolutional neural network. The model displayed a good predictive performance.

• Journal of Gastric Cancer
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• v.3 no.4
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• pp.191-194
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• 2003

Purpose: Neuroendocrine carcinomas of the stomach account for only about $0.3\%$ of all gastric tumors. The prognosis of this disease is very poor compared with the common type of gastric adenocarcinoma. The purpose of this retrospective study was to review the clinicopathologic features of 18 cases of this unusual gastric tumor and to establish a treatment strategy for this tumor. Materials and Methods: Excluding 2 cases of non-curative resection and 1 case of operative mortality, 18 cases of typical neuroendocrine carcinoma who had curative resection from January 1991 to December 2000 at Asan Medical Center were analyzed; 6841 gastric cancer patient were treated surgically during the same period. Results: The mean age at the time of diagnosis was 58.6 years (range: $35\∼75$ yr). Sixteen patients were male, and two were female. Eleven tumors ($61.1\%$) developed in the lower part of the stomach, three ($16.7\%$) in the middle part, and three ($16.7\%$) in the upper part. One tumor involved the entire stomach. Eight cases ($44.4\%$) were Borrmann type 2, and six case ($33.3\%$) were Borrmann type 3. The mean tumor size was 6.94 cm (range: $0.6\∼15$ cm). Nine cases ($50\%$) showed recurrence of the disease, and eight of them died within 20 months. Of the nine recurred cases, 7 cases ($77.8\%$) showed liver metastasis. The mean disease-free interval was 6.8 months (range: $2.5\∼11$ months) after surgical resection, and the mean survival was 17.9 months (range: $8\∼40$ months) for recurrence cases. One patient with liver metastasis was treated with a liver-wedge resection just after diagnosis and was still alive for 37.5 months postoperatively. There were 9 deaths after the median follow- up period of 40 months (range: $8\∼72$ months). Conclusion: Gastric neuroendocrine carcinomas frequently recur at the liver, even in early stage cancer, and have a poor prognosis. We experienced a case of successful control of hepatic metastasis by surgical resection and a case of a small cell carcinoma which was successfully controlled with systemic chemotherapy.

• Journal of Chest Surgery
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• v.50 no.4
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• pp.308-311
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• 2017

A 71-year-old man was referred for an anterior chest wall mass. Chest computed tomography (CT) and positron emission tomography-CT suggested a malignant tumor. Surgical biopsy through a vertical subxiphoid incision revealed an extra-gastrointestinal stromal tumor (EGIST). En bloc resection of the tumor, including partial resection of the sternum, costal cartilage, pericardium, diaphragm, and peritoneum, was performed. Pathologic evaluation revealed a negative resection margin and confirmed the tumor as an EGIST. On postoperative day 17, the patient was discharged without any complications. At the 2-week follow-up, the patient was doing well and was asymptomatic.

• Journal of Yeungnam Medical Science
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• v.23 no.1
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• pp.131-137
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• 2006

Small bowel tumors have been difficult to diagnose because of low incidence and absence of specific symptoms. There are no efficient and accurate tests available for diagnosis. Capsule endoscopy is an efficient diagnostic tool for small bowel disease and obscure gastrointestinal bleeding. We diagnosed two cases of small bowel gastrointestinal stromal tumor (GIST) diagnosed by capsule endoscopy that were treated by surgery. A 68 year old male presented with abdominal pain. The capsule endoscopy showed fungating ulcer mass at the jejunum. A 55 year female presented with melena. The capsule endoscopy showed an intraluminal protruding mass with a superficial ulcer at the jejunum. Two cases were diagnosed with GIST after surgery. We report these two case diagnosed by capsule endoscopy and review the medical literature.

• Journal of Gastric Cancer
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• v.14 no.1
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• pp.58-62
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• 2014

We report an extremely rare case of primary squamous cell carcinoma of the stomach. A 69-year-old man was admitted to our hospital with a 2-month history of dysphagia and tarry stools. Endoscopic examination revealed a cauliflower-shaped protruding mass along the lesser curvature of the gastric cardia. Biopsy of the lesion revealed squamous cell carcinoma of the stomach. Computed tomography revealed a thickened stomach wall and a mass protruding into the gastric lumen. Total gastrectomy with splenectomy, distal pancreatectomy, and Roux-en-Y reconstruction was performed, together with a lower thoracic esophagectomy via a left thoracotomy. Histopathological examination of the specimen revealed well-differentiated squamous cell carcinoma of the stomach. Postoperative follow-up was uneventful for the first 18 months. However, multiple liver metastases and para-aortic lymph node metastasis developed subsequently. Despite systemic combination chemotherapy, the patient died because of progression of the recurrent tumors. Here, we review the characteristics of 56 cases of gastric squamous cell carcinoma reported in Japan.

• Journal of the Korean Society of Radiology
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• v.83 no.2
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• pp.400-405
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• 2022

Gastrointestinal stromal tumors (GISTs) are not uncommon and often cause gastrointestinal bleeding. GISTs occurring in the small intestine are occasionally difficult to identify by endoscopy and CT. In this case, the patient underwent CT three times before surgery, and the lesion was found to be located in a different area of the abdominal cavity on each CT scan. Moreover, the lesion was missed in the first two CT images because it was difficult to distinguish it from the nearby collapsed small intestine. The lesion was eventually detected through angiography; however, the correct diagnosis and treatment were delayed for 3 years because it was mistaken for a vascular malformation, which is the most common cause of obscure GI bleeding in elderly patients. This report emphasizes the need for interventional radiologists to be updated and vigilant of the angiographic features of GISTs to make an accurate diagnosis and establish a management strategy.