Publications by authors named "Kensuke Yokoyama"

A 50-year-old man was diagnosed with type 1 autoimmune pancreatitis (AIP) following endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) and a histopathological examination. After six months of untreated follow-up, the serum IgG4 level decreased, and the diffuse pancreatic enlargement improved; however, a pancreatic head mass became apparent. EUS-FNA of this mass revealed pancreatic ductal adenocarcinoma (PDAC) with IgG4-positive plasma cells.

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Article Synopsis
  • This study looked into how different factors affect the successful removal of bile duct stones in patients with altered anatomy undergoing a specific endoscopic procedure called DBERC.
  • Of the 257 patients analyzed, over half achieved initial stone removal, but around 21% experienced stone recurrence, with key factors impacting these outcomes identified.
  • Factors like the size and number of stones were crucial for successful removal, while complications such as cholangitis and congenital biliary dilatation were linked to higher chances of stone recurrence.
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Article Synopsis
  • Endoscopic ultrasonography (EUS) is a key diagnostic tool for identifying diseases in organs close to the gastrointestinal tract.
  • EUS-guided fine-needle aspiration (FNA) enhances the accuracy of histopathological diagnosis.
  • The evolution of EUS-FNA over 40 years, including advancements in scopes, observation systems, and puncture tools, paves the way for future innovations.
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Article Synopsis
  • * Imaging suggested intrapancreatic bile duct stenosis, resembling autoimmune pancreatitis, even though key pancreatic enzyme levels remained normal.
  • * A biopsy revealed inflammation and fibrosis, and the patient responded well to treatment with oral prednisolone, with no signs of recurrent pancreatitis after dosage reduction.
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Background: /Objectives: This study aimed to evaluate the usefulness of three-dimensional (3D) immunohistochemistry for the Ki67 index of small tissue specimens of pancreatic neuroendocrine tumor (PanNET).

Methods: Clinicopathological materials from 17 patients with PanNET who underwent surgical resection at Jichi Medical University Hospital were analyzed. We compared the Ki67 index of endoscopic ultrasonography-fine-needle aspiration biopsy (EUS-FNAB) specimens, surgical specimens, and small tissue specimens hollowed from paraffin blocks of surgical specimens that were substituted for EUS-FNAB specimens ("sub-FNAB").

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A 66-year-old man diagnosed with immunoglobulin G4-related sclerosing cholangitis (IgG4-SC) with diffuse intrahepatic bile duct stenosis and elevated serum IgG4 levels was referred for a further examination because of elevated serum carbohydrate antigen 19-9 levels despite treatment with corticosteroids. An umbilical nodule was found on a physical examination and a biopsy showed adenocarcinoma. Although several imaging studies revealed no changes from prior studies, bile cytology collected by endoscopic retrograde cholangiopancreatography showed adenocarcinoma.

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During balloon enteroscopy-assisted endoscopic retrograde cholangiography, the minimal water exchange method facilitates reaching the site and prevents pneumobilia, hepatic portal venous gas, and air embolism. However, the water may mix with bile or blood, obscuring the visual field. Yokoyama and colleagues demonstrate how the gel immersion method helps overcome this problem.

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Endoscopic ultrasound can be useful for obtaining detailed diagnostic images for pancreatic disease. Contrast-enhanced harmonic endoscopic ultrasound has allowed to demonstrate not only microvasculature but also real perfusion imaging using second-generation contrast agents. Furthermore, endoscopic ultrasound fine-needle aspiration cytology and histology have become more ubiquitous; however, the risk of dissemination caused by paracentesis has yet to be resolved, and the application of less invasive contrast-enhanced endoscopic ultrasound for the differential diagnosis of pancreatic tumors has been anticipated.

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Balloon enteroscopy-assisted endoscopic retrograde cholangiography (BEA-ERC) is useful and feasible in adults with pancreatobiliary diseases, but its efficacy and safety have not been established in pediatric patients. We compared the success rate and safety of BEA-ERC between adults and pediatric patients. This single-center retrospective study reviewed 348 patients (pediatric: 57, adult: 291) with surgically altered gastrointestinal anatomies who underwent BEA-ERC for biliary disorders from January 2007 to December 2019.

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Autoimmune pancreatitis (AIP), which is characterized by pancreatic enlargement and irregular narrowing of the main pancreatic duct, is difficult to differentiate from malignancy. The irregular narrowing of the pancreatic duct, which can be detected via endoscopic retrograde cholangiopancreatography, is a characteristic feature of AIP; however, distinguishing between localized AIP and pancreatic cancer based on pancreatic duct imaging is difficult. This study overviews the efficacy of endoscopic ultrasound (EUS)-guided pancreatic sampling for the histopathological diagnosis of AIP.

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The number of new cases of pancreatic ductal adenocarcinoma is increasing with a cumulative total of 495,773 cases worldwide, making it the fourteenth most common malignancy. However, it accounts for 466,003 deaths per year and is the seventh leading cause of cancer deaths. Regional differences in the number of patients with pancreatic ductal adenocarcinoma appear to reflect differences in medical care, as well as racial differences.

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Autoimmune pancreatitis (AIP) is characterized by enlargement of the pancreas and irregular narrowing of the main pancreatic duct. It is often associated with IgG4-related sclerosing cholangitis (IgG4-SC), in which the bile duct narrows. Although characteristic irregular narrowing of the pancreatic duct caused by endoscopic retrograde cholangiopancreatography is noted in AIP, it is difficult to differentiate between localized AIP and pancreatic carcinoma based on imaging of the pancreatic duct.

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Tumor seeding after endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) is rare. A 53-year-old man underwent transesophageal EUS-FNA for diagnosis of a 6-cm mass in the mediastinum as seen by computed tomography (CT). Four weeks later, repeat CT scan revealed a mass in the esophageal wall.

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Pancreatic metastasis from colorectal cancer is rare, and there have been only a few reports of its preoperative diagnosis by endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) with immunohistochemical staining. We herein describe the case of a 77-year-old woman in whom a solitary mass in the pancreatic tail was detected 11 years after rectal cancer resection. The patient also had a history of pulmonary tumor resection.

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 Short-type single-balloon enteroscope (short SBE)-assisted endoscopic retrograde cholangiopancreatography (ERCP) is a promising alternative treatment in postsurgical altered anatomy. However, it is technically demanding, and factors affecting its technical difficulty have not yet been clarified. This study aimed to examine the procedural success rate of short SBE-assisted ERCP and the potential factors affecting procedural failure.

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A 21-year-old female underwent a Kasai hepatoportoenterostomy with Roux-en-Y reconstruction for typeIII biliary atresia at age 63 days. At the age of 19 years, she developed cholangitis and CT scan revealed hepatolithiasis. She presented for treatment of the intrahepatic stone and the hepatportoenterostomy was directly visualized with double-balloon endoscopy (DBE).

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