Eiji Ishii

Molecular Genotyping of Anisakis Larvae in Middle Eastern Japan and Endoscopic Evidence for Preferential Penetration of Normal over Atrophic Mucosa

Background Anisakiasis is a parasitic disease caused primarily by Anisakis spp. larvae in Asia and in Western countries. The aim of this study was to investigate the genotype of Anisakis larvae endoscopically removed from Middle Eastern Japanese patients and to determine whether mucosal atrophy affects the risk of penetration in gastric anisakiasis. Methods In this study, 57 larvae collected from 44 patients with anisakiasis (42 gastric and 2 colonic anisakiasis) were analyzed retrospectively. Genotyping was confirmed by restriction fragment length polymorphism (RFLP) analysis of ITS regions and by sequencing the mitochondrial small subunit (SSU) region. In the cases of gastric anisakiasis, correlation analyses were conducted between the frequency of larval penetration in normal/atrophic area and the manifestation of clinical symptoms. Results Nearly all larvae were A. simplex seusu stricto (s.s.) (99%), and one larva displayed a hybrid genotype. The A. simplex larvae penetrated normal mucosa more frequently than atrophic area (p = 0.005). Finally, patients with normal mucosa infection were more likely to exhibit clinical symptoms than those with atrophic mucosa infection (odds ratio, 6.96; 95% confidence interval, 1.52–31.8). Conclusions In Japan, A. simplex s.s. is the main etiological agent of human anisakiasis and tends to penetrate normal gastric mucosa. Careful endoscopic examination of normal gastric mucosa, particularly in the greater curvature of the stomach will improve the detection of Anisakis larvae.

Lymph node metastasis after endoscopic submucosal dissection of a differentiated gastric cancer confined to the mucosa with an ulcer smaller than 30 mm

In the expanded indications for endoscopic resection, Japanese guidelines for gastric cancer include differentiated cancers confined to the mucosa with an ulcer <30 mm. We describe a patient with lymph node metastasis after curative endoscopic submucosal dissection (ESD) for a tumor of this indication. The patient was a 70‐year‐old man with chronic hepatitis C. He underwent ESD for early gastric cancer in May 2010. Pathology revealed a moderately differentiated adenocarcinoma, 22 × 17 mm in size, that was confined to the mucosa with an ulcer. The horizontal and vertical margins were negative for the tumor. We diagnosed thiscase as curative resection of expanded indication and followed this patient with endoscopy, abdominal ultrasonography (AUS) or enhanced computed tomography (CT) approximately every 6 months. After 17 months, lymph node metastasis was detected with AUS and CT and diagnosed by endoscopic ultrasound‐guided fine‐needle aspiration biopsy in August 2011. Distal gastrectomy with D2 dissection was carried out in December 2011. Although it is low, the possibility of recurrence should be borne in mind after endoscopic treatment of early gastric cancer, despite its inclusion in the expanded indications for endoscopic resection.

Granular cell tumor of the common bile duct: A Japanese case

Granular cell tumor (GCT) of the biliary system is rare. It is reported that it occurs more commonly in young black women. We report here our seldom experience of a Japanese case in whom icterus was found as a first symptom just after a caesarean operation. A 36-year-old Japanese woman developed icterus after delivery by the Caesarean operation. A surgical operation was performed without can deny that there was a tumor-related change in a bile duct as a result of examination for various images. As a result of pathological evaluation, GCT was diagnosed. By the preoperative organization biomicroscopy result, it was not able to be attachd a right diagnosis. It was thought that this tumor, although rare, should be considered as one of the causes of biliary stenosis in the younger population.

Gastrointestinal stromal tumor of the ampulla of Vater: a case report.

Gastrointestinal stromal tumors (GISTs) usually develop in the stomach and small intestine and only rarely occur at the ampulla of Vater, with only 11 cases reported in the literature. We report a case of a GIST of the ampulla of Vater. A 36-year-old, previously healthy man presented with a loss of consciousness lasting a few minutes. A gastroduodenal endoscopy revealed a submucosal tumor with central ulceration at the ampulla of Vater. The enhanced computed tomography scan revealed a smooth-outlined hypervascular solid mass (24 mm × 30 mm) in the second part of the duodenum. Neither lymphadenopathy nor metastasis was observed. Magnetic resonance cholangiopancreatography and endoscopic retrograde cholangiopancreatography showed normal bile and pancreatic ducts. Biopsies were collected from the ulcerative lesion, and the tumor was diagnosed as a GIST. A submucosal tumor with central ulceration may be a characteristic form of GISTs of the ampulla of Vater, and biopsy studies are useful for the diagnosing such tumors. The patient underwent pancreatoduodenectomy, and the operative specimen revealed a 2.2-cm GIST with 1 mitosis per 50 high-power fields. The gold standard for treatment of GISTs is surgical resection without rupture of a capsule. If technically possible, local resection may be considered. However, when the location of the lesion presents challenges, a pancreatoduodenectomy should be performed for GIST of the ampulla of Vater.

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

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.

Endoscopic retrograde cholangiopancreatography using a cap-assisted highly flexible colonoscope in patients with Roux-en-Y anastomosis.

In this retrospective study of 10 patients with Roux-en-Y anastomosis, endoscopic retrograde cholangiopancreatography (ERCP) using a cap-assisted thin highly flexible colonoscope was done for treatment of bile duct stones. In five patients, the papilla of Vater was successfully reached using the colonoscope alone. However, in the other five patients, combination with an overtube was needed to reach the papilla. In all cases, complete removal of bile duct stones was accomplished. Procedure-related adverse events occurred in two cases. In conclusion, use of a cap-assisted thin highly flexible colonoscope for ERCP was successful in patients with a Roux-en-Y anastomosis.

Pseudoaneurysm caused by a self-expandable metal stent: a report of three cases

We present three cases of pseudoaneurysm caused by self-expandable metal stents that formed arteriobiliary fistulas and caused hemobilia. Diagnoses were made on the basis of dynamic computed tomography or angiography. One patient died because of bleeding and cholangitis, whereas the others were successfully treated by transarterial embolization.