Faculty Profiles - IWAMURO Masaya

Adenocarcinoma In Situ Arising from Brunner's Gland Treated by Endoscopic Mucosal Resection. Reviewed International journal

Masaya Iwamuro, Sayo Kobayashi, Nobuya Ohara, Seiji Kawano, Yoshiro Kawahara, Hiroyuki Okada

Case reports in gastrointestinal medicine 2017 7916976 - 7916976 2017

Authorship：Lead author,　Corresponding author Language：English

An 86-year-old Japanese man was presented to our hospital for further investigation of duodenal adenocarcinoma. The tumor was endoscopically resected. Pathological analysis revealed coexistence of gastric foveolar metaplasia and a surrounding hyperplastic Brunner's gland, in addition to an adenocarcinoma component. Immunostaining for MUC5AC and MUC6 confirmed the diagnosis of adenocarcinoma in situ arising from Brunner's gland hyperplasia. This case suggests that although detailed preoperative evaluation is required to determine the depth of tumor invasion, endoscopic resection may be a promising option for the treatment of adenocarcinomas arising from Brunner's gland hyperplasia.

DOI： 10.1155/2017/7916976

Pseudomelanosis duodeni: A case report Reviewed

Masaya Iwamuro, Shohei Oka, Hiromitsu Kanzaki, Takehiro Tanaka, Seiji Kawano, Yoshiro Kawahara, Hiroyuki Okada

Journal of Japanese Society of Gastroenterology 114 ( 7 ) 1264 - 1268 2017

Language：Japanese Publishing type：Research paper (scientific journal) Publisher：Japanese Society of Gastroenterology

An 83-year-old Japanese man underwent esophagogastroduodenoscopy for screening purposes. He had a medical history of hypertension, chronic kidney disease, chronic heart failure, and chronic myeloid leukemia, and he had been taking the following medications: ferrous citrate, furosemide, spironolactone, tolvaptan, bisoprolol, nicorandil, warfarin, nilotinib, febuxostat, esomeprazole, digestive enzyme complex, ambroxol, carbocysteine, and potassium L-aspartate. Esophagogastroduodenoscopy revealed a brownish speckled pigmentation in the duodenal bulb. Biopsy specimens from the duodenal villi revealed a brown pigment deposition, which appeared bright on scanning electron microscopy. Energy dispersive X-ray spectroscopy and elemental mapping revealed the presence of iron and sulfur in the duodenal villi. Consequently, pseudomelanosis duodeni was diagnosed based on these findings.

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Intravascular lymphoma with a gastric submucosal tumor Reviewed

Hiroaki Sawahara, Masaya Iwamuro, Mamoru Ito, Soichiro Nose, Mamoru Nishimura, Hiroyuki Okada

Journal of Japanese Society of Gastroenterology 114 ( 8 ) 1446 - 1453 2017

Language：Japanese Publishing type：Research paper (scientific journal) Publisher：Japanese Society of Gastroenterology

A 75-year-old man was admitted to our hospital for further examination of swollen lymph nodes and a possible gastric submucosal tumor. He had persistent fever and anorexia. Blood examination showed anemia, thrombocytopenia, and elevated lactate dehydrogenase and soluble interleukin 2 receptor levels. Swollen lymph nodes and splenomegaly were evident on computed tomography, and the submucosal tumor was revealed by esophagogastric endoscopy. Cervical lymph node biopsy and endoscopic biopsy were performed, which revealed a diagnosis of intravascular lymphoma. In Asian countries, patients with intravascular lymphoma often have hemophagocytic syndrome without lesions of the central nervous system or skin, which is called the Asian variant of intravascular lymphoma. In this case, the patient had no indicative lesions and had no evidence of the hemophagocytic syndrome. He also had lymph node swelling and a gastric submucosal tumor, which are rare in intravascular lymphoma The patient was treated with chemotherapy (R-CHOP
rituximab-cyclophosphamide, doxorubicin, vincristine, and prednisolone), and complete response was demonstrated (based on the Response Evaluation Criteria for Solid Tumours [RECIST] guideline). In cases of possible intravascular lymphoma, gastrointestinal endoscopy and biopsy should be considered because they are a useful diagnostic strategy.

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Colonoscopy examination requires a longer time in patients with acromegaly than in other individuals Reviewed

Iwamuro Masaya, Yasuda Miho, Hasegawa Kou, Fujisawa Satoshi, Ogura-Ochi Kanako, Sugihara Yuusaku, Harada Keita, Hiraoka Sakiko, Okada Hiroyuki, Otsuka Fumio

Endocrine Journal 65 ( 2 ) 151 - 157 2017

Authorship：Lead author,　Corresponding author Language：English Publisher：The Japan Endocrine Society

<p>This study aimed to determine the prevalence of colorectal neoplasms and to investigate the rate of and time required for cecal intubation in patients with acromegaly. A database search performed at our institution identified 29 patients with acromegaly who underwent colonoscopy. Data regarding the endoscopic, biological, and pathological examinations performed were retrospectively reviewed from the clinical records. Subsequently, the rate of and time required for cecal intubation were investigated in 23 patients with acromegaly and compared with the corresponding data of the control group. Control subjects were selected from a 2:1 matched historical control cohort, according to baseline characteristics. The mean age of the acromegaly group (17 female and 12 male) was 60.4 ± 12.6 years. Twelve patients had adenoma (41.4%), eight patients had hyperplastic polyps (27.6%), three patients had sessile serrated adenoma/polyps (10.3%), and three patients had colon cancer (10.3%). Successful cecal intubation was achieved in all patients in both groups. The difference in the time required for successful intubation between the acromegaly group (15.7 ± 9.8 minutes) and the control group (8.7 ± 6.0 minutes) was statistically significant. Linear regression analysis revealed that increased patient age was significantly related to longer colonoscope insertion times. In conclusion, although cecal intubation during colonoscopy was successful in all participants, it required a longer time in patients with acromegaly. Our results underscore the importance of and certain technical difficulties involved in colonoscopy procedures in patients with acromegaly, especially in older patients.</p>

DOI： 10.1507/endocrj.EJ17-0322

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The Clinical and Hormonal Characteristics of Primary Adrenal Lymphomas: The Necessity of Early Detection of Adrenal Insufficiency Reviewed

Ko Harada, Kosuke Kimura, Masaya Iwamuro, Tomohiro Terasaka, Yoshihisa Hanayama, Eisei Kondo, Eiko Hayashi, Tadashi Yoshino, Fumio Otsuka

INTERNAL MEDICINE 56 ( 17 ) 2261 - 2269 2017

Language：English Publishing type：Research paper (scientific journal) Publisher：JAPAN SOC INTERNAL MEDICINE

Objective To analyze the clinical and endocrine characteristics of patients with primary adrenal lymphoma.
Patients We retrospectively reviewed the cases of five patients with primary adrenal lymphoma who were treated in our hospital between April 2004 and March 2015. We investigated the characteristics of the clinical and pathological findings, treatment, prognosis and complications of adrenal insufficiency.
Results Adrenal insufficiency, which was confirmed by the laboratory data at the initial presentation, was observed in two cases. One case was complicated by relative adrenal insufficiency during a course of chemotherapy. The plasma adrenaline and urinary adrenaline levels were decreased in four cases and three cases, respectively. Diffusion MRI was radiologically diagnostic. In all of the cases, the patients were pathologically diagnosed with diffuse large-B cell lymphoma and were treated with rituximab and CHOP (cyclophosphamide, doxorubicin, vincristine and prednisone)-like chemotherapy. Two patients received central nervous system prophylaxis with high-dose methotrexate. Four of the patients survived and one patient died during the follow-up period.
Conclusion The early detection of adrenal insufficiency and the administration of an appropriate dose of hydrocortisone are necessary during the course of chemotherapy as well as at the initial manifestation. The exclusion of adrenal dysfunction prior to invasive diagnostic procedures, such as CT-guided needle biopsy, is also critical.

DOI： 10.2169/internalmedicine.8216-16

Paroxysmal Hypertension Induced by an Insulinoma Reviewed

Ko Harada, Yoshihisa Hanayama, Kou Hasegawa, Masaya Iwamuro, Hideharu Hagiya, Ryuichi Yoshida, Fumio Otsuka

INTERNAL MEDICINE 56 ( 4 ) 413 - 417 2017

Language：English Publishing type：Research paper (scientific journal) Publisher：JAPAN SOC INTERNAL MEDICINE

Insulinoma is a rare, usually benign, pancreatic neuroendocrine tumor. The clinical features of an insulinoma are fasting hypoglycemia with neuroglycopenic symptoms including confusion and unusual behavior, while hypertension is usually not associated with the disease. We herein report a patient with insulinoma who manifested paroxysmal hypertension and neuroglycopenic symptoms. The possible etiology of hypertension induced by an insulinoma is catecholamine release in response to hypoglycemia, which may cause acute hypertension through activation of the sympatho-adrenal system. This case implies that sustained hyperinsulinemia due to insulinoma can be functionally linked to the induction of paroxysmal hypertension.

DOI： 10.2169/internalmedicine.56.7758

Hepatic and Gastric Involvement in a Case of Systemic Sarcoidosis Presenting with Rupture of Esophageal Varices Reviewed

Hiroaki Saito, Masayasu Ohmori, Masaya Iwamuro, Takehiro Tanaka, Nozomu Wada, Tetsuya Yasunaka, Akinobu Takaki, Hiroyuki Okada

INTERNAL MEDICINE 56 ( 19 ) 2583 - 2588 2017

Language：English Publishing type：Research paper (scientific journal) Publisher：JAPAN SOC INTERNAL MEDICINE

A 46-year-old woman presented with massive hematemesis, caused by the rupture of esophageal varices. The laboratory investigations showed pancytopenia, and imaging tests revealed hepatosplenomegaly and ascites. A diagnosis of systemic sarcoidosis was made based on biopsies of the liver, stomach, lungs, heart, and skin. Although fat deposition was predominant, non-caseating granuloma and cirrhotic changes were found in the liver. Non-caseating granuloma was also identified in a biopsy specimen from minute depressions of the gastric folds. This case illustrates the rare involvement of the digestive system in a case of systemic sarcoidosis.

DOI： 10.2169/internalmedicine.8768-16

Safety and Efficacy of Small Bowel Examination by Capsule Endoscopy for Patients before Liver Transplantation Reviewed

Kawano Seiji, Takaki Akinobu, Iwamuro Masaya, Yasunaka Tetsuya, Kono Yoshiyasu, Miura Kou, Inokuchi Toshihiro, Kawahara Yoshiro, Umeda Yuzo, Yagi Takahito, Okada Hiroyuki

BIOMED RESEARCH INTERNATIONAL 2017 2017

Language：English Publishing type：Research paper (scientific journal) Publisher：HINDAWI LTD

Background and Aims. Gastrointestinal surveillance is a requirement prior to liver transplantation (LT), but small intestine examination is not generally undertaken. The aim of the present studywas to evaluate the safety and efficacy of capsule endoscopy (CE) for patients with end-stage liver disease. Methods. 31 patients who needed LT were enrolled, and 139 patients who underwent CE over the same period of time acted as controls. Results. Frequency of successful achievement of evaluation of the full length of the small bowel, the mean gastric transit time, and the mean small bowel transit time were not significantly different between the two groups. Abnormalities in the small bowel were found in 26 patients. Comparative analysis revealed that history of EV rupture, history of EV treatment, red color sign of EV, and presence of PHG or HCC were significantly associated with patients with >2 two such findings (high score group). Conclusions. Small bowel examination by CE in patients before liver transplantation could be performed safely and is justified by the high rate of abnormal lesions detected particularly in patients with history of EV therapy or bleeding, red color sign, and presence of PHG or HCC. This study was registered in the UMIN Clinical Trial Registry (UMIN 000008672).

DOI： 10.1155/2017/8193821

Gastroduodenal Intussusception with a Gastric Gastrointestinal Stromal Tumor Treated by Endoscopic Submucosal Dissection Reviewed

Kenji Yamauchi, Masaya Iwamuro, Eiji Ishii, Makoto Narita, Nobuto Hirata, Hiroyuki Okada

INTERNAL MEDICINE 56 ( 12 ) 1515 - 1519 2017

Language：English Publishing type：Research paper (scientific journal) Publisher：JAPAN SOC INTERNAL MEDICINE

A 95-year-old Japanese woman presented to our hospital with intermittent vomiting and several episodes of melena. Abdominal computed tomography revealed intussusception of the gastric tumor into the duodenum. After endoscopic reduction, endoscopic ultrasonography identified a hypoechogenic lesion limited to the submucosal layer. Endoscopic resection was performed as a localized treatment for the prevention of recurrent gastroduodenal intussusception. To our knowledge, there have been no other reports describing a gastric gastrointestinal stromal tumor presenting with gastroduodenal intussusception and treated using an endoscopic submucosal dissection technique.

DOI： 10.2169/internalmedicine.56.8160

Importance of Second-look Endoscopy on an Empty Stomach for Finding Gastric Bezoars in Patients with Gastric Ulcers Reviewed

Masaya Iwamuro, Shouichi Tanaka, Yuki Moritou, Tomoki Inaba, Reiji Higashi, Chiaki Kusumoto, Naoko Yunoki, Shin Ishikawa, Yuko Okamoto, Yoshinari Kawai, Ken-ichi Kitadal, Ryuta Takenaka, Tatsuya Toyokawa, Hiroyuki Okada

ACTA MEDICA OKAYAMA 71 ( 3 ) 241 - 247 2017

Language：English Publishing type：Research paper (scientific journal) Publisher：OKAYAMA UNIV MED SCHOOL

Most gastric bezoars can be treated with endoscopic fragmentation combined with or without cola dissolution, whereas laparotomy or laparoscopic surgery is generally inevitable for small intestinal bezoars because they cause small bowel obstruction. Therefore, early diagnosis and management of gastric bezoars are necessary to prevent bezoar-induced ileus. To investigate the incidence of overlooked gastric bezoars during the initial esophagogastroduodenoscopy, we retrospectively reviewed the cases of 27 patients diagnosed with gastrointestinal bezoars. The bezoars were diagnosed using esophagogastroduodenoscopy (n=25), abdominal ultrasonography (n=1), and barium follow-through examination (n=1). Bezoars were overlooked in 9/25 patients (36.0%) during the initial endoscopy examination because the bezoars were covered with debris in the stomach. Of the 9 patients, 8 had concomitant gastric ulcers, and the other patient had gastric lymphoma. Although a computed tomography (CT) scan was performed before the second-look endoscopy in 8 of the 9 patients, the bezoars were mistaken as food debris on CT findings and were overlooked in these patients. In conclusion, gastric bezoars may not be discovered during the initial esophagogastroduodenoscopy and CT scan. In cases with debris in the stomach, second-look endoscopy is essential to detect bezoars.

Diffuse Intestinal Ganglioneuromatosis Showing Multiple Large Bowel Ulcers in a Patient with Neurofibromatosis Type 1 Reviewed

Masaya Iwamuro, Rika Omote, Takehiro Tanaka, Naruhiko Sunada, Takahiro Nada, Yoshitaka Kondo, Soichiro Nose, Mitsuhiko Kawaguchi, Fumio Otsuka, Hiroyuki Okada

INTERNAL MEDICINE 56 ( 24 ) 3287 - 3291 2017

Language：English Publishing type：Research paper (scientific journal) Publisher：JAPAN SOC INTERNAL MEDICINE

A 67-year-old Japanese man with neurofibromatosis type 1 underwent right hemicolectomy owing to abscess formation around the cecum. A pathological analysis revealed diffuse intestinal ganglioneuromatosis in the cecum and colon. Colonoscopy performed eight months after hemicolectomy revealed multiple ulcers throughout the colon and rectum. The colorectal ulcers failed to respond to conservative treatment and ultimately required surgical resection. Diffuse ganglioneuromatosis was observed again in the resected specimen. This report illustrates a rare manifestation of diffuse intestinal ganglioneuromatosis in a patient with neurofibromatosis type 1.

DOI： 10.2169/internalmedicine.8671-16

Clinical Characteristics of Seven Patients with Lanthanum Phosphate Deposition in the Stomach Reviewed

Naoko Murakami, Masao Yoshioka, Masaya Iwamuro, Junichirou Nasu, Soichiro Nose, Junji Shiode, Hiroyuki Okada, Kazuhide Yamamoto

INTERNAL MEDICINE 56 ( 16 ) 2089 - 2095 2017

Language：English Publishing type：Research paper (scientific journal) Publisher：JAPAN SOC INTERNAL MEDICINE

Objective To analyze the clinical characteristics and endoscopic features of patients with lanthanum deposition in the stomach.
Patients We retrospectively reviewed seven patients with lanthanum deposition in the stomach who were diagnosed at Okayama Saiseikai General Hospital. We investigated the patient sex, age at diagnosis, medical and medication histories, gastrointestinal symptoms, complications, presence or absence of gastric atrophy, and outcome. We also investigated any changes in the endoscopic features if previous endoscopic images were available.
Results Seven patients (six males and one female) had lanthanum deposition. The median age was 65 years (range, 50-79 years). All patients had been undergoing dialysis (continuous ambulatory peritoneal dialysis in one patient, hemodialysis in six patients). The dialysis period ranged from 16 to 73 months (median, 52 months). The patients had all been taking lanthanum carbonate for a period ranging from 5 to 45 months (median, 27 months). Gastric atrophy was noted in 6 patients (85.7%). One patient had difficulty swallowing, and 1 other patient had appetite loss. The other 5 patients were asymptomatic. Endoscopic features included annular whitish mucosa (n = 4), diffuse whitish mucosa (n = 3), and whitish spots (n = 2). Five patients underwent multiple esophagogastroduodenoscopy. The endoscopic features were unchanged in 2 patients, whereas the whitish mucosa became apparent and spread during the course in 3 patients.
Conclusion We identified 7 patients with lanthanum deposition in the stomach. All patients showed whitish lesions macroscopically. Although the pathogenicity of gastric lanthanum deposition is uncertain, lanthanum-related lesions in the stomach progressed during continuous lanthanum phosphate intake in several patients.

DOI： 10.2169/internalmedicine.8720-16

Changes of colonic mucosa caused by long-term use and discontinuation of anthraquinone

Iwano Eiji, Iwamuro Masaya, Okada Hiroyuki

Okayama Igakkai Zasshi (Journal of Okayama Medical Association) 129 ( 1 ) 23 - 30 2017

Language：Japanese Publisher：Okayama Medical Association

Anthraquinone, an anthracene derivatives, is widely used as a purgative medicine. The long-term use of anthraquinone is known to cause melanosis coli and elevated lesions in the colon. However, the clinical course of patients who take anthraquinone over a long term and those who discontinue the drug has not been fully investigated. Here we investigated 22 patients who had colonic mucosal changes (i.e., melanosis coli and elevated lesions) who had been taking anthraquinone for at least one year and discontinued it. We classified the elevated lesions into two subtypes: the small-lesion, which included multiple small nodules that were < 2 mm in dia., and the large-lesion, which included a single or multiple nodules of ≥ 2-mm dia. We used colonoscopy to investigate the changes of colonic lesions between before and after the discontinuation of anthraquinone. The results indicated that the nodules of the small-lesion group were lymphoid follicle hyperplasia. In the large-lesion group, adenoma was most frequently observed (n＝118), followed by hyperplastic polyp (n＝52) and inflammatory changes with edema (n＝22). Melanosis coli and elevated lesions were decreased or invisible after the discontinuation of anthraquinone. Our findings thus suggest that the long-term use of anthraquinone may cause some type of elevated lesions due to chronic inflammation. It is recommended that the use of anthraquinone be limited to a short term.

DOI： 10.4044/joma.129.23

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