Koji Namekata
Juntendo University
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Featured researches published by Koji Namekata.
Case Reports in Gastroenterology | 2015
Yoshihiko Tashiro; Fumio Matsumoto; Keiko Iwama; Ai Shimazu; Sei Matsumori; Shigeo Nohara; Hiroyoshi Miura; Masahiko Takei; Koji Namekata; Masaru Takase; Motoi Okada; Hidenori Tsumura
Schwannomas of the colon are rare and difficult to diagnose preoperatively. We report a case of schwannoma of the ascending colon that was resected laparoscopically. A 64-year-old woman was referred to our hospital by her local clinic for further evaluation and management of a submucosal tumor of the ascending colon. A definitive preoperative diagnosis could not be reached despite examinations. Gastrointestinal stromal tumor, leiomyoma and lymphoma were the differential diagnoses. We performed a laparoscopic right hemicolectomy with D2 lymph node dissection. Histological findings with hematoxylin-eosin staining revealed spindle-like tumor cells, and immunohistochemical analysis showed that the tumor was positive for S-100 but negative for c-kit, CD34, smooth muscle actin and desmin, with a Ki-67 index of <5%. Thus, the diagnosis in this case was benign schwannoma of the ascending colon.
International Journal of Surgery Case Reports | 2015
Hirohiko Kamiyama; Ai Shimazu; Yurika Makino; Ryosuke Ichikawa; Takahiro Hobo; Shuei Arima; Shigeo Nohara; Yuji Sugiyama; Masafumi Okumura; Masahiko Takei; Hiroyoshi Miura; Koji Namekata; Hidenori Tsumura; Motoi Okada; Masaru Takase; Fumio Matsumoto
Highlights • A very rare case of large retroperitoneal mucinous cystadenocarcinoma and little-known clinical course of the disease is reported.• The disease took unexpectedly aggressive progression despite the small portion of adenocarcinoma for the multiple and large cysts.• Informative findings in imaging of primary retroperitoneal mucinous cyst adenocarcinoma, and impressive imaging after recurrence are presented.
Case Reports in Gastroenterology | 2010
Yutaka Kojima; Fumio Matsumoto; Yoshi Mikami; Koji Namekata; Masahiko Takei
We present the case of a 68-year-old female patient who was diagnosed with cancer of the descending colon in July 1994 and underwent partial resection of the colon (type 2, moderately to well differentiated adenocarcinoma, se, ly1, v1, n(–)). In April 1996, she was admitted to a nearby hospital for symptoms of ileus, which improved at the hospital. However, she was referred to our hospital for melena. In blood test, Hb was 8.7 g/dl, showing anemia, and carcinoembryonic antigen level was elevated to 50.7 ng/ml. Abdominal CT and small bowel series showed only mild expansion of the small bowel, suggesting no obvious occlusion. Abdominal surgery was performed in May 1995 for repeated development of ileus symptoms and suspicion of bleeding from the small bowel. Since the findings of the abdominal surgery showed a circular tumor in the lower ileum, partial resection of the small bowel was performed. Histopathological examination showed type 3, moderately to well differentiated adnocarcinoma, se, ly2, v0, n = 1/13. The principal tumor was located within the subserosa and grew up exclusively through the muscularis propria and the submucosa, into the mucous layer. The mucosa remained slightly on the surface layer. Based on these findings, the patient was diagnosed with metastasis of descending colon cancer to the small bowel. Her prognosis was good, and neither metastasis nor redevelopment of the cancer have been confirmed to date, 11 years and 7 months since the surgery.
Nihon Rinsho Geka Gakkai Zasshi (journal of Japan Surgical Association) | 2000
Hiroyuki Sugo; Toyohito Iwata; Jiro Yoshimoto; Koji Namekata; Kuniaki Kojima; Masaki Fukasawa; Tomoe Beppu; Shunji Futagawa
The Japanese Journal of Gastroenterological Surgery | 2014
Hirohiko Kamiyama; Yurika Makino; Takahiro Hobo; Shigeo Nohara; Yuji Sugiyama; Masahiko Takei; Hiroyoshi Miura; Koji Namekata; Fumio Matsumoto
Jpn J Gastroenterol Surg, Nihon Shokaki Geka Gakkai zasshi | 2008
Yutaka Kojima; Humio Matsumoto; Youshi Mikami; Koji Namekata; Masahiko Takei; Kiichi Sugimoto; Daisuke Fujiwara; Yusuke Oyama
Nihon Gekakei Rengo Gakkaishi (journal of Japanese College of Surgeons) | 2015
Hirohiko Kamiyama; Yurika Makino; Shigeo Nohara; Yuji Sugiyama; Hiroyoshi Miura; Koji Namekata; Hidenori Tsumura; Fumio Matsumoto
Clinical Journal of Gastroenterology | 2014
Hirohiko Kamiyama; Ryosuke Ichikawa; Shuei Arima; Yuji Sugiyama; Masahiko Takei; Koji Namekata; Hidenori Tsumura; Masaru Takase; Motoi Okada; Fumio Matsumoto
Nihon Gekakei Rengo Gakkaishi (journal of Japanese College of Surgeons) | 2003
Koji Namekata; Toyohito Iwata; Shigeru Takamori; Kuniaki Kojima; Masaki Fukasawa; Tomoe Beppu; Shunji Futagawa
Jpn J Gastroenterol Surg, Nihon Shokaki Geka Gakkai zasshi | 2001
Koji Namekata; Kensuke Morioka; Shigeru Takamori; Kuniaki Kojima; Masaki Fukasawa; Tomoe Beppu; Shunji Futagawa