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Featured researches published by Shin Arai.


Modern Pathology | 2004

Endoscopic mucosal resection for gastric epithelial neoplasms: a study of 39 cases with emphasis on the evaluation of specimens and recommendations for optimal pathologic analysis.

Gregory Y. Lauwers; Shinichi Ban; Mari Mino; Shinichi Ota; Takayuki Matsumoto; Shin Arai; Hoi-Hung Chan; William R. Brugge; Michio Shimizu

Endoscopic mucosal resection of gastric neoplasms is a curative technique that avoids surgery and its potential complications. Infrequently performed in the West, the limitations, pitfalls and challenges provided by this new therapeutic modality are not well known by general surgical pathologists. We evaluated a series of 39 endoscopic mucosal resections and assessed the correlation between original biopsies and final diagnoses, depth of excision, status of deep and lateral margins, artifactual changes and recurrence rate. The tumors consisted of 24 intramucosal carcinomas, six high-grade dysplasias, eight low-grade dysplasias and one submucosal invasive carcinoma. The preresection diagnoses corresponded to the final evaluation in 63% of the cases with previous biopsies. In 37% of the cases, the biopsies under-diagnosed the neoplasia. The rate of positive margins was 38%. Iatrogenic changes, that is, intramucosal hemorrhage and electrodiathermic burn, were noted in 44% of the cases but hindered the pathologic evaluation in only 10% of the cases. Persistence or recurrence was observed in only seven cases and there was no progression to advanced adenocarcinoma. Based on our experience, we offer some recommendations in order to provide optimal pathologic analysis of endoscopic mucosal resection specimens.


World Journal of Gastrointestinal Endoscopy | 2010

Short term results of endoscopic submucosal dissection in superficial esophageal squamous cell neoplasms.

Kouichi Nonaka; Shin Arai; Keiko Ishikawa; Masamitsu Nakao; Yousuke Nakai; Osamu Togawa; Koji Nagata; Michio Shimizu; Yutaka Sasaki; Hiroto Kita

AIM To evaluate the efficacy of endoscopic submucosal dissection for superficial esophageal squamous cell neoplasms. METHODS Between July 2007 and March 2009, 27 consecutive superficial esophageal squamous cell neoplasms in 25 enrolled patients were treated by endoscopic submucosal dissection. The therapeutic efficacy, complications, and follow-up results were assessed. RESULTS The mean size of the lesions was 21 ± 13 mm (range 2-55 mm); the mean size of the resection specimens was 32 ± 12 mm (range 10-70 mm). The en block resection rate was 100% (27/27), and en block resection with tumor-free lateral/basal margins was 88.9% (24/27). Perforation occurred in 1 patient who was managed by conservative medical treatments. None of the patients developed local recurrence or distant metastasis in the follow-up period. CONCLUSION Endoscopic submucosal dissection is applicable to superficial esophageal squamous cell neoplasms with promising results.


Digestive Endoscopy | 2011

Prospective study of the evaluation of the usefulness of tumor typing by narrow band imaging for the differential diagnosis of gastric adenoma and well-differentiated adenocarcinoma.

Kouichi Nonaka; Shin Arai; Shinichi Ban; Hideki Kitada; Masaaki Namoto; Koji Nagata; Yasutoshi Ochiai; Osamu Togawa; Masamitsu Nakao; Makoto Nishimura; Keiko Ishikawa; Yutaka Sasaki; Hiroto Kita

Background and Aim:  Presently, the differential diagnosis of gastric adenoma and well‐differentiated adenocarcinoma by endoscopy is very difficult. We carried out magnifying endoscopy with narrow band imaging (NBI) in lesions that required discrimination between gastric adenoma and well‐differentiated adenocarcinoma, and prospectively evaluated whether the tumor typing that we propose is useful for their differential diagnosis.


World Journal of Gastrointestinal Endoscopy | 2012

Usefulness of the DL in ME with NBI for determining the expanded area of early-stage differentiated gastric carcinoma

Kouichi Nonaka; Masaaki Namoto; Hideki Kitada; Michio Shimizu; Yasutoshi Ochiai; Osamu Togawa; Masamitsu Nakao; Makoto Nishimura; Keiko Ishikawa; Shin Arai; Hiroto Kita

AIM To investigate whether magnifying endoscopy with narrow band imaging (ME-NBI) is useful for evaluating the area of superficial, depressed- or flat-type differentiated adenocarcinoma of the stomach. METHODS This procedure was performed in Saitama Medical University International Medical Center, Japanese Red Cross Kumamoto Hospital and Kitakyushu Municipal Medical Center. The subjects were 31 patients in whom biopsy findings, from superficial, depressed- or flat-type gastric lesion, suggested differentiated adenocarcinoma in the above 3 hospitals between January and December 2009. Biopsy was performed on the lesion and non-lesion sides of a boundary (imaginary boundary) visualized on ME-NBI. The results were pathologically investigated. We evaluated the accuracy of estimating a demarcation line (DL) on ME-NBI in comparison with biopsy findings as a gold standard. RESULTS The DL that could be recognized at 2 points on the orifice and anal sides of each lesion during ME-NBI was consistent with the pathological findings in 22 patients with 0-IIc lesions, 7 with 0-IIb lesions, and 2 with 0-IIb + IIc lesions, showing an accuracy of 100%. CONCLUSION The results suggest the usefulness of ME-NBI for evaluating the area of superficial, depressed- and flat-type differentiated adenocarcinoma of the stomach.


Journal of Gastroenterology and Hepatology | 2009

Gastrointestinal: Gastric mucosa-associated lymphoma presented with unique vascular features on magnified endoscopy combined with narrow-band imaging

Kouichi Nonaka; Keiko Ishikawa; Michio Shimizu; Takaki Sakurai; Yousuke Nakai; Masamitsu Nakao; Kiyoko Yoshino; Shin Arai; Hiroto Kita

Gastric lymphoma arising from mucosal associated lymphoid tissue (MALT) has distinct clinical and histological characteristics compared with nodal B-cell lymphoma. Magnified endoscopy (ME) combined with narrow band imaging (NBI) is widely used and the usefulness is well recognized for the diagnosis of gastritis and gastric cancer. However, there has been no report on ME combined with NBI for gastric MALT lymphoma, despite the necessity of differentiating it from gastric cancer. We report a case ofgastricMALTlymphomainwhichMEcombinedwithNBIcould detectuniquevascularfeaturesdifferentfromthoseseenincircumscribed atrophic gastritis or poorly differentiated adenocarcinoma. A 66-year-old woman underwent endoscopic screening of the upper gastrointestinal tract revealed ill-defined, brownish, superficial depressed lesion in the anterior wall of the upper gastric body (Fig. 1). ME combined with NBI system, consisting of an image processor (CV-260SL, Olympus Medical Systems, Tokyo, Japan), a light source (CLV-260SL), and a zoom endoscope (GIF-Q240Z) showed the disappearance of the surface structure and the appearance of abnormal blood vessels.Abnormal vessels were defined as new vessels that were not seen in the adjacent mucosa. They were large vessels like a tree trunk with long, bare branches that can be called as ‘tree like appearance’ (Fig. 2). Biopsy was taken from this abnormal portion and revealed hyperplasia of atypical centrocyte-like cells with small to medium-sized, ovoid nuclei and clear cytoplasm in the lamina propria mucosae and their infiltration among glandular epithelial cells, suggesting lymphoepithelial lesion. The atypical lymphocytes were immunohistochemically CD20+ ,C D10-, and CD5-. These findings were consistent with gastric MALT lymphoma. In this case report, we have shown that the tree-like appearance of the abnormal blood vessels, clearly observed by ME with NBI, could be one of the unique features suggestive of gastric MALT lymphoma. This finding could be helpful because superficial depressed type lesion potentially include circumscribed atrophic gastritis and poorly differentiated adenocarcinoma. Of note, these vascular findings are relatively easy to detect by using NBI, because NBI can present clearly defined vascular image. Therefore, our data also suggest the importance of NBI for the endoscopic evaluation of gastric MALTlymphoma.The combination of ME with NBI may also reduce the number of biopsy of gastric MALT lymphoma because it can provide precise information about the distribution of MALT lymphoma in the stomach.


Digestive Endoscopy | 2014

Is narrow-band imaging useful for histological evaluation of gastric mucosa-associated lymphoid tissue lymphoma after treatment?

Kouichi Nonaka; Ken Ohata; Nobuyuki Matsuhashi; Michio Shimizu; Shin Arai; Yoshimitsu Hiejima; Hiroto Kita

Endoscopic diagnosis of stomach mucosa‐associated lymphoid tissue (MALT) lymphoma is often difficult because few specific findings are indicated. Even when MALT lymphoma is suspected by endoscopy, it is still difficult to make a definitive diagnosis by biopsy because lymphoma cells sometimes distribute unevenly. We previously reported that a tree‐like appearance (TLA) is a characteristic finding of MALT lymphoma by narrow‐band imaging (NBI) magnifying endoscopy and it is valuable in the selection of an optimal biopsy site in MALT lymphoma. Here, we study the frequency of TLA and evaluate the relationship between the response to eradication therapy and TLA in MALT lymphoma.


World Journal of Gastrointestinal Endoscopy | 2012

A case of gastric mucosa-associated lymphoid tissue lymphoma in which magnified endoscopy with narrow band imaging was useful in the diagnosis

Kouichi Nonaka; Keiko Ishikawa; Shin Arai; Masamitsu Nakao; Michio Shimizu; Takaki Sakurai; Koji Nagata; Makoto Nishimura; Osamu Togawa; Yasutoshi Ochiai; Yutaka Sasaki; Hiroto Kita

Recently, we reported a case of gastric mucosa-associated lymphoid tissue (MALT) lymphoma presenting with unique vascular features. In the report, we defined the tree-like appearance (TLA) on the images of abnormal blood vessels which resembled branches from the trunk of a tree in the shiny mucosa, in which the glandular structure was lost. The 67-year-old female was diagnosed with gastric MALT lymphoma. The patient received eradication therapy for H. pylori. Conventional endoscopy revealed multiple ill-delineated brownish depressions in the stomach and cobblestone-like mucosa was observed at the greater curvature to the posterior wall of the upper gastric body 7 mo after successful eradication. Unsuccessful treatment of gastric MALT lymphoma was suspected on conventional endoscopy. Conventional endoscopic observations found focal depressions and cobblestone-like appearance, and these lesions were subsequently observed using magnified endoscopy combined with narrow band imaging to identify abnormal vessels presenting with a TLA within the lesions. Ten biopsies were taken from the area where abnormal vessels were present within these lesions. Ten biopsies were also taken from the lesions without abnormal vessels as a control. A total of 20 biopsy samples were evaluated to determine whether the diagnosis of MALT lymphoma could be obtained histologically from each sample. A positive diagnosis was obtained in 8/10 TLA (+) sites and in 2/10 TLA(-) sites. Target biopsies of the site with abnormal blood vessels can potentially improve diagnostic accuracy of gastric MALT lymphoma.


Biomedical Reports | 2017

Increased neutrophil-to-lymphocyte ratio is a novel marker for nutrition, inflammation and chemotherapy outcome in patients with locally advanced and metastatic esophageal squamous cell carcinoma

Yu Sato; Kenji Gonda; Maiko Harada; Yuki Tanisaka; Shin Arai; Yumi Mashimo; Hirotoshi Iwano; Hiroshi Sato; Shomei Ryozawa; Takao Takahashi; Shinichi Sakuramoto; Masahiko Shibata

Esophageal squamous cell carcinoma (ESCC) is one of the most common types of cancer, and its progression is strongly influenced by the presence of inflammation. Recently, there has been growing interest in the host inflammatory response, and increasing evidence has indicated that the neutrophil-to-lymphocyte ratio (NLR), a useful marker of systemic inflammation, may be an effective prognostic indicator in various types of malignant diseases. In the present study, 260 patients with ESCC were enrolled, including 110 who received chemoradiation therapy (CRT) involving irradiation and chemotherapy of 5-fluorouracil and cisplatin, and 150 received chemotherapy using 5-fluorouracil and cisplatin (FP). The patients of each group were both divided into two groups according to their NLR: High NLR (NLR>3.0) and low NLR (NLR≤3.0). Serum levels of prealbumin and retinol binding protein, which are nutritional parameters, were both significantly inversely correlated with NLR in patients treated with CRT, and patients treated with FP. Levels of CRP, a marker of inflammation, were significantly correlated with NLR, and stimulation indices, markers of immune reactions, were inversely correlated with NLR in both of CRT patients and FP patients. In patients treated with CRT, a partial response was significantly higher in patients with a low NLR and with progressive disease compared to those with a high NLR. In patients treated with FP, a partial response was also significantly higher in patients with a low NLR and with progressive disease compared to those with a high NLR. The overall survival of patients with CRT and FP were both significantly worse in patients with a high NLR than in those with a low NLR. NLR may serve as a useful marker of the tumor response, immune suppression, malnutrition and prognosis upon CRT or FP in patients with locally advanced or metastatic ESCC.


Oncology Letters | 2018

Usefulness of endoscopic ultrasound‑guided fine needle aspiration for lymphadenopathy

Yuki Tanisaka; Shomei Ryozawa; Masanori Kobayashi; Maiko Harada; Tsutomu Kobatake; Kumiko Omiya; Hirotoshi Iwano; Shin Arai; Kouichi Nonaka; Yumi Mashimo

Lymphadenopathy may be difficult to diagnose using imaging results alone. Endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) may help to diagnose and determine the appropriate management of lymphadenopathy. EUS-FNA has been used as a safe and less invasive method for obtaining pathologic specimens from extraluminal lesions using endoscopic ultrasound. The present study evaluated the usefulness of EUS-FNA for lymphadenopathy. Between July 2013 and December 2016, 72 patients undergoing EUS-FNA for lymphadenopathy that could not be diagnosed solely using imaging were included. The present study evaluated the sensitivity, specificity, positive and negative predictive value, overall accuracy, helpfulness in determining the management of lymphadenopathy and EUS-FNA-associated complications. Of the 72 included patients, 8 were diagnosed with benign (inflammatory or reactive) lymphadenopathy. The diagnostic sensitivity, specificity, positive and negative predictive value, and overall accuracy were 95.3, 100, 100, 72.7 and 95.8%, respectively. While EUS-FNA of metastatic nodes identified the origin in the majority of cases, the procedure resulted in a different histopathological diagnosis from the previous image-based diagnosis in 9 patients. Consequently, 2 patients with testicular cancer were administered bleomycin, etoposide, and cisplatin. An individual with GIST was administered imatinib, and a patient with prostate cancer was administered degarelix (antihormon drug). A total of 5 other patients received palliative medicine due to the change in diagnosis. EUS-FNA also helped determine the appropriate cancer management plan in other patients; specifically, based on the cytology of the metastatic lymph node, EUS-FNA helped determine the cancer stage, and to identify recurrence or the primary cancer from which tissue could not be collected. No EUS-FNA-associated symptoms were reported. To conclude, the present study suggested that EUS-FNA of suspected metastatic lymph nodes appears safe and useful for cancer staging and diagnosing recurrence. It may also useful for diagnosing patients whose collection of samples from the original cancer appeared impractical. EUS-FNA for lymphadenopathy that may not be diagnosed with imaging alone may assist in diagnosis and help to determine the appropriate management strategy.


Diagnostic and Therapeutic Endoscopy | 2014

Status of the Gastric Mucosa with Endoscopically Diagnosed Gastrointestinal Stromal Tumor

Kouichi Nonaka; Shinichi Ban; Yoshimitsu Hiejima; Rei Narita; Michio Shimizu; Masayasu Aikawa; Ken Ohata; Nobuyuki Matsuhashi; Shin Arai; Hiroto Kita

Background. Since gastrointestinal stromal tumor (GIST) is a mesenchymal submucosal tumor, the endosonographic, CT, and MRI features of gastric GISTs have been widely investigated. However, the GIST-bearing gastric mucosa status has not been reported. Objective. To characterize the GIST-bearing gastric mucosa status in terms of the degree of inflammation and atrophy, assessed endoscopically. Subjects and Methods. The subjects were 46 patients with submucosal tumors (histologically proven gastric GISTs) who had undergone upper gastrointestinal endoscopy in our hospital between April 2007 and September 2012. They were retrospectively evaluated regarding clinicopathological features, the endoscopically determined status of the entire gastric mucosa (presence or absence and degree of atrophy), presence or absence and severity of endoscopic gastritis/atrophy (A-B classification) at the GIST site, and presence or absence of H. pylori infection. Results. Twenty-three patients had no mucosal atrophy, but 17 and 6 had closed- and open-type atrophy, respectively. Twenty-six, 5, 12, 1, 1, and 1 patients had grades B0, B1, B2, B3, A0, and A1 gastritis/atrophy at the lesion site, respectively, with no grade A2 gastritis/atrophy. Conclusion. The results suggest that gastric GISTs tend to arise in the stomach wall with H. pylori-negative, nonatrophic mucosa or H. pylori-positive, mildly atrophic mucosa.

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Keiko Ishikawa

Saitama Medical University

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Masamitsu Nakao

Saitama Medical University

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Kouichi Nonaka

Saitama Medical University

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Osamu Togawa

Saitama Medical University

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Makoto Nishimura

Saitama Medical University

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Kenji Fujiwara

Saitama Medical University

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Yukinori Imai

Saitama Medical University

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Michio Shimizu

Saitama Medical University

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