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Featured researches published by Takeshi Mazaki.


Pathology International | 2003

Irritated seborrheic keratosis of the external ear canal

Eiichi Konishi; Yasuaki Nakashima; Toshiaki Manabe; Takeshi Mazaki; Yoshimasa Wada

Although a seborrheic keratosis is not rare on the skin of the trunk, extremities, head and neck of an elderly person, it is uncommon to originate in the external ear canal. Even rarer, an irritated subtype may arise in this location. We report the case of a 63‐year‐old man with an irritated seborrheic keratosis arising in the right external ear canal, who first presented with a bloody discharge from his right ear canal 3 years and 10 months before the subsequent operation. Macroscopically, a dome‐like, black elevation was found at the anterior wall of the right external ear canal. A biopsy showed an exophytic papillomatous, hyperkeratotic growth of basaloid cells which revealed some nuclear atypism and mitosis. Squamous eddies and moderate inflammatory infiltrate were noted. Some cellular atypism made us suspect an irritated seborrheic keratosis. Because the patient hated the extirpation, he remained untreated for 3 years and 3 months following his first presentation. The biopsy and a surgical resection of his second presentation confirmed the diagnosis of irritated seborrheic keratosis. Immunohistochemical analysis of Ki‐67, p53 and papillomavirus was performed to elucidate its character. We emphasize that irritated seborrheic keratosis does occur in the external ear canal and may cause some diagnostic difficulty. Pathologists should be aware of this fact and avoid overdiagnosis.


Journal of Telemedicine and Telecare | 2000

The current status of medicolegal issues surrounding telepathology and telecytology in Japan.

Yasunari Tsuchihashi; Yoshikazu Okada; Yoichi Ogushi; Takeshi Mazaki; Yutaka Tsutsumi; Takashi Sawai

The medicolegal issues surrounding telepathology and telecytology in Japan have been partly resolved since the government declared that telediagnosis in these fields using a microscope is essentially a medical practice between doctors. Thus it does not contravene article 20 of the law pertaining to medical practice in Japan, which states that there must be an actual face-to-face encounter between the doctor performing any diagnostic or treatment episode and the patient. It is, however, only beginning to be recognized that the medicolegal issues surrounding telepathology and telecytology depend on factors such as the type of system used (e.g. active versus passive). In an active diagnostic system, the telepathologist or telecytopathologist can control a robotic microscope at the remote site, while in a passive diagnostic system the telepathologist or telecytopathologist makes the diagnosis based on the microscope images that have been selected, and transmitted, by someone in the remote hospital. In the former case the interpreting telepathologist or telecytopathologist must assume most of the responsibility for the diagnostic process, while in the latter more responsibility must be assumed by those at the remote site. The duties and responsibilities of all participants in the telediagnostic process, whatever the system employed, must be determined. We have established working guidelines for telepathological and telecytological diagnoses to help achieve this and hence ensure safe and effective clinical practice.


Endoscopy | 2014

L-menthol improves adenoma detection rate during colonoscopy: a randomized trial.

Ken Inoue; Osamu Dohi; Yasuyuki Gen; Masayasu Jo; Takeshi Mazaki; Kazuhiko Tokita; Naohisa Yoshida; Tetsuya Okayama; Kazuhiro Kamada; Kazuhiro Katada; Kazuhiko Uchiyama; Takeshi Ishikawa; Osamu Handa; Tomohisa Takagi; Hideyuki Konishi; Naoki Wakabayashi; Nobuaki Yagi; Yuji Naito; Yoshito Itoh

BACKGROUND AND STUDY AIMS Colonoscopy is one of the most reliable methods for the detection of colorectal neoplasms. However, colonic peristalsis during colonoscopy results in some neoplastic lesions being hidden from view and commonly requires an intravenous or intramuscular injection of antispasmodic agents, which may sometimes causes unexpected adverse reactions. The aim of this study was to evaluate the efficacy of L-menthol spray as an antiperistaltic agent and its effect on adenoma detection. PATIENTS AND METHODS This was a prospective, randomized, single-blind placebo-controlled trial. A total of 226 patients who were scheduled to undergo colonoscopy were randomly assigned to receive either 20 mL of 1.6 % L-menthol (n = 118) or placebo (n = 108). Both treatments were sprayed locally onto the colonic mucosa via an endoscope. The adenoma detection rate (ADR) and the proportion of patients with no peristalsis were the primary and secondary outcomes, respectively. RESULTS The ADR was significantly higher in the L-menthol group than in the placebo group (60.2 % vs. 42.6 %; P = 0.0083). The proportion of patients with no peristalsis after treatment with L-menthol was significantly higher than in the placebo group (71.2 % vs. 30.9 %; P < 0.0001). There were no adverse effects in either group. CONCLUSIONS The results suggest that the suppression of colonic peristalsis by L-menthol sprayed directly onto the colonic mucosa improves the ADR. CLINICAL TRIAL REGISTRATION ID: UMIN 000007972.


Acta Cytologica | 2003

Cytologic features of atypical polypoid adenomyoma of the endometrium: A case report

Junji Kimura; Hironobu Okamoto; Hiroyuki Yamamoto; Takeshi Mazaki; Tadahisa Kitamura

BACKGROUND In 1981, Mazur reported the histologic characteristics of atypical polypoid adenomyoma (APA) of the endometrium. Although most APAs of the endometrium are considered to show benign behavior, there is a small associated risk of the development of adenocarcinoma. The histology of APA of the endometrium is well defined, but the cytologic features of the lesion have not yet been clarified. CASE A 28-year-old nulligravida with hypermenorrhea had an exophytic, polypoid mass arising from the posterior uterine wall on ultrasonography and magnetic resonance imaging. The results of endometrial smear and biopsy were normal. Transcervical total resection of the tumor was performed with a resectoscope. Frozen sections of the sample suggested APA of the endometrium, and the permanent sections confirmed the diagnosis. The tumor stump/resection plane smears revealed overlapping, highly atypical glandular cells with enlarged, hyperchromatic nuclei; squamous metaplastic cells; and abundant, spindled smooth muscle cells on a clear background, effectively reflecting the epithelial and mesenchymal cell components of the lesion. CONCLUSION Endometrial smear and biopsy are inaccurate methods for the diagnosis of APA of the endometrium because of limited sampling. Tumor stump/resection plane cytology appears to be useful for detecting APA of the endometrium.


World Journal of Surgical Oncology | 2012

Anatomical liver segmentectomy 2 for combined hepatocellular carcinoma and cholangiocarcinoma with tumor thrombus in segment 2 portal branch

Hiromichi Ishii; Takuma Kobayashi; Michihiro Kudou; Masumi Nishimura; Atsushi Toma; Kenji Nakamura; Takeshi Mazaki; Tsuyoshi Itoh

BackgroundHepatic resection is the only effective treatment for combined hepatocellular carcinoma and cholangiocarcinoma.Case presentationA 52-year-old man was preoperatively diagnosed with hepatocellular carcinoma in segment 2 with tumor thrombus in the segment 2 portal branch. Anatomical liver segmentectomy 2, including separation of the hepatic arteries, portal veins, and bile duct, enabled us to remove the tumor and portal thrombus completely. Modified selective hepatic vascular exclusion, which combines extrahepatic control of the left and middle hepatic veins with occlusion of left hemihepatic inflow, was used to reduce blood loss. A pathological examination revealed combined hepatocellular carcinoma and cholangiocarcinoma with tumor thrombus in the segment 2 portal branch. No postoperative liver failure occurred, and remnant liver function was adequate.ConclusionThe separation method of the hepatic arteries, portal veins, and bile duct is safe and feasible for a liver cancer patient with portal vein tumor thrombus. Modified selective hepatic vascular exclusion was useful to control bleeding during liver transection. Anatomical liver segmentectomy 2 using these procedures should be considered for a patient with a liver tumor located at segment 2 arising from a damaged liver.


Case Reports in Gastroenterology | 2010

A Case of Neuroendocrine Cell Carcinoma with Sigmoidovesical Fistula.

Tsutomu Kawaguchi; Tsuyoshi Itoh; Atsushi Toma; Nobuaki Fuji; Takeshi Mazaki; Kazuyo Naito; Eigo Otsuji

Colonic neuroendocrine cell carcinoma (NEC), which is a rare subtype of colon epithelial neoplasm, has been reported to show extremely aggressive characteristics with a 1-year survival rate of 20%. We report herein a resected case of NEC that manifested bacterial sepsis due to sigmoidovesical fistula. Staged surgery consisted of resecting the sigmoid colon and part of the bladder four weeks after construction of an ileostomy to alleviate septic shock. The resected specimen was histologically diagnosed as NEC invading the wall of the urinary bladder with metastasis to the regional lymph nodes. The patient underwent four cycles of FOLFOX after surgery for additional treatment of residual metastatic lymph nodes around the abdominal aorta diagnosed preoperatively. Although the patient showed stable disease measured by computed tomography scan for the first three months after surgery, he rejected additional chemotherapy thereafter, and died ten months after the initial admission due to progression of residual tumor in the urinary bladder as well as the lymph nodes. This is the first case report describing colonic NEC manifesting perforation into the urinary bladder. Although the optimal chemotherapeutic regimen for colonic NEC has not yet been established, FOLFOX may be one of the choices.


World Journal of Gastroenterology | 2005

Multifocal intraportal invasion of breast carcinoma diagnosed by laparoscopy-assisted liver biopsy

Tomoki Nakajima; Satoru Sekoguchi; Taichirou Nishikawa; Hidetaka Takashima; Tadashi Watanabe; Masahito Minami; Yoshito Itoh; Naruhiko Mizuta; Hiroo Nakajima; Takeshi Mazaki; Akio Yanagisawa; Takeshi Okanoue


The Journal of the Japanese Society of Clinical Cytology | 2004

Required adjustments for obtaining digital cytology images using telecytology

Takeshi Mazaki; Yasunari Tsuchihashi


Nihon Rinsho Geka Gakkai Zasshi (journal of Japan Surgical Association) | 2018

A Case of Bile Peritonitis due to Intrahepatic Bile Duct Perforation

Masato Mitsuda; Nobuyuki Watanabe; Hiroshi Ito; Atsushi Toma; Takeshi Mazaki; Toshiya Ochiai; Eigo Otsuji


Nihon Rinsho Geka Gakkai Zasshi (journal of Japan Surgical Association) | 2014

A Case of Adenoendocrine Cell Carcinoma of the Gallbladder

Shinpei Ogino; Takeshi Ishimoto; Atsushi Toma; Takeshi Mazaki; Toshiya Ochiai; Eigo Otsuji

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Atsushi Toma

Kyoto Prefectural University of Medicine

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Eigo Otsuji

Kyoto Prefectural University of Medicine

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Yasunari Tsuchihashi

Kyoto Prefectural University of Medicine

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Yoshito Itoh

Kyoto Prefectural University of Medicine

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Hideyuki Konishi

Kyoto Prefectural University of Medicine

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Kazuhiko Tokita

Kyoto Prefectural University of Medicine

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Kazuhiko Uchiyama

Kyoto Prefectural University of Medicine

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Kazuhiro Kamada

Kyoto Prefectural University of Medicine

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Kazuhiro Katada

Kyoto Prefectural University of Medicine

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Ken Inoue

Kyoto Prefectural University of Medicine

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