Ryohei Kaji

Autoimmune pancreatitis presenting with IgG4-positive multiple gastric polyps

Autoimmune pancreatitis (AIP) occurs in association with a variety of multiorgan pathologies. AIP coexists most often with sclerosing cholangitis, and involvement of the lachrymal gland, salivary gland, thyroid gland, lymph nodes, and retroperitoneum has been reported, although these are less common. It has been reported that gastric ulcers are associated with AIP, even though these are actually rare. We encountered a case of IgG4-positive multiple inflammatory gastric polyps in a patient with AIP. We believe that there are no similar previous reports, so we present our findings as a case report.

Comparison of sclerosing cholangitis with autoimmune pancreatitis and infiltrative extrahepatic cholangiocarcinoma: multidetector-row computed tomography findings

PurposeThe aim of this study was to compare multidetector-row computed tomography (MDCT) findings between cases of sclerosing cholangitis with autoimmune pancreatitis (SC-AIP) and infiltrative extrahepatic cholangiocarcinoma (IEC).Materials and methodsWe retrospectively assessed MDCT findings from 16 IEC cases and 13 SC-AIP cases. MDCT findings were analyzed with regard to location, length, wall thickness, contour, stricture wall enhancement pattern, proximal duct diameter, and the presence of diffuse concentric thickening in the proximal duct and gallbladder wall thickness.ResultsStricture length, stricture wall thickness, and proximal duct diameter were significantly smaller for SC-AIP than for IEC: 19.3 ± 8.7 vs. 31.8 ± 12.0 mm (P = 0.004), 2.1 ± 1.3 vs. 4.1 ± 1.3 mm (P < 0.001), and 9.2 ± 3.9 vs. 13.3 ± 5.0 mm (P = 0.012), respectively. SC-AIP was correlated with stricture location in both the intrapancreatic and hilar hepatic bile ducts, concentric stricture contour (P < 0.001), and diffuse concentric thickening of the proximal bile duct (P = 0.010). Overall values of sensitivity, specificity, and accuracy used to distinguish between SC-AIP and IEC for stricture wall thickness of <3.0 mm and concentric contour were 76.9%, 93.8%, and 86.2%, respectively, and 100%, 87.5%, 93.1%, respectively.ConclusionConcentric contour and stricture wall thicknesses of <3.0 mm may help distinguish between SC-AIP and IEC.

Serum immunoglobulin G4 associated with number and distribution of extrapancreatic lesions in type 1 autoimmune pancreatitis patients

Background and Aim:  Type 1 autoimmune pancreatitis (AIP) is characterized by the increase of serum immunoglobulin (Ig)G4 and abundant IgG4 plasma cell infiltration in the pancreas and various extrapancreatic lesions (EPL), which are proposed as IgG4‐related disease. We assessed the correlation between serum IgG4 and the number of EPL, and the association between serum IgG4 and the distribution of EPL in type 1 AIP patients.

DIRECT CHOLANGIOSCOPY USING A DOUBLE‐BALLOON ENTEROSCOPE: CHOLEDOCHOJEJUNOSTOMY WITH INTRADUCTAL BILIARY CARCINOMA

A 75‐year‐old man who underwent choledochojejunostomy for gallstones 30 years ago was hospitalized for general malaise. Abdominal computed tomography revealed marked dilation of the intrahepatic bile duct in the right lobe and an image of a hypervascular tumor. Endoscopic retrograde cholangiography using double‐balloon enteroscopy (DBE) showed a filling defect that was localized to the right hepatic bile duct. Furthermore, the scope was able to readily pass through the anastomosed site of the choledochojejunostomy and, therefore, we observed the interior of the bile duct using the same scope. We obtained an image showing a whitish, papillary‐like tumor, and a biopsy of the tumor rendered the pathology of intraductal papillary mucinous carcinoma. Direct cholangioscopy using DBE is a useful diagnostic tool, particularly in patients with a past history of choledochojejunostomy.

THE MANAGEMENT OF THE PANCREATIC CYSTIC NEOPLASM: THE ROLE OF THE EUS IN JAPAN

Diagnosis of cystic lesions of the pancreas is made by clinical history taking, physical examination, blood biochemical tests and diagnostic imaging, such as transabdominal ultrasound, endoscopic ultrasound (EUS), cross‐sectional imaging (computed tomography and/or magnetic resonance imaging) and endoscopic retrograde cholangiopancreatography, bearing in mind the known characteristic features of the various cystic lesions that can occur in this organ. Among others, EUS, endowed with a sharp local resolving power, has been described as a highly useful examination method, because it enables concurrent fine‐needle aspiration (FNA). EUS has an important role in the differential diagnosis and tumor grading (benign, premalignant or malignant) of cystic lesions. Although the differential diagnosis of cystic lesions of the pancreas based on EUS morphology is practicable to some extent, there have also been reports showing that the diagnosis might vary with the endosonographer and that the diagnostic performance of this method for tumor grading is not necessarily high. In countries overseas, differential diagnosis and tumor grading of cystic lesions of the pancreas are actively undertaken not merely by EUS morphology, but also by cyst‐fluid EUS‐guided FNA (EUS‐FNA) cytology and measurements of pancreatic enzymes and tumor markers, and importance is attached to EUS‐FNA in the latest version of the American Society for Gastrointestinal Endoscopy Guideline and in the diagnostic strategies for cystic diseases of the pancreas. Meanwhile, the current Japanese consensus is that EUS‐FNA is not recommended in cases of mucinous cystic lesions suspected as being intraductal papillary mucinous neoplasm or mucinous cystic neoplasm.

ENDOSCOPIC RETRIEVAL OF MIGRATED PLASTIC STENT INTO BILE DUCT OR PANCREATIC PSEUDOCYST

Proximally migrated biliary plastic stent and migrated stent in the pancreatic pseudocyst are relatively rare complications. A migrated stent causes poor drainage conditions, which leads to secondary complications such as infection, abscess, perforation and, moreover, becomes a foreign object in the body, and retrieval or re‐stenting is therefore necessary. The retrieval of a migrated stent includes surgical, percutaneous and endoscopic approaches, and the most non‐invasive method is endoscopic retrieval. However, because very few devices are exclusively designed for retrieval, the current situation is that the available devices are used while taking advantage of various ideas and techniques. From previously reported cases and our experiences of such cases, we herein describe the methods of endoscopic retrieval for stents that have migrated into a bile duct or pancreatic pseudocysts.

The utility of a novel antibody in the pathological diagnosis of pancreatic acinar cell carcinoma

Aims Acinar cell carcinomas (ACCs) are rare tumours of the exocrine pancreas accounting for about 1–2% of all pancreatic neoplasms in adults. It is therefore difficult to come across a large number of ACC cases in a single medical institution, and only a few serial studies have been published. Since ACCs present a wide variety of morphological patterns, immunohistochemical analysis is useful. In this study, the authors established a novel monoclonal antibody 2P-1-2-1 by means of a subtractive immunisation method. Methods Immunohistochemical staining was performed using 50 primary pancreatic tumors, including 7 ACCs, 7 neuroendocrine tumours (NETs), 5 solid-pseudopapillary neoplasms (SPNs), and 31 ductal carcinomas and organs other than the pancreas. Results Non-neoplastic acinar cells were stained diffusely, but epithelial cells of the pancreatic duct and the islets of Langerhans were not stained. In pancreatic tumours, all the seven ACCs were diffusely positive for the 2P-1-2-1 antibody. However, no positive staining was found in other pancreatic tumours including NETs, SPNs and ductal adenocarcinomas. The sensitivity and specificity of the 2P-1-2-1 antibody for ACCs were both 100%. In other organs studied, positive staining was observed only in the ectopic pancreas. Conclusions It was shown that the 2P-1-2-1 antibody specifically stained the pancreatic acinar cells and tumours of acinar cell origin, such as ACCs. Although it remains unclear at this time to which proteins the monoclonal antibody 2P-1-2-1 is directed, it is suggested to be useful for the pathological diagnosis of ACCs and for the exclusion of other pancreatic tumours.

Accuracy of differential diagnosis for pancreatic cancer is improved in the combination of RCAS1 and CEA measurements and cytology in pancreatic juice

Improvement of diagnostic accuracy for pancreatic cancer in pancreatic disease patients was investigated by examining the combination of three diagnostic methods, i.e., measurements of RCAS1 and CEA levels in pancreatic juice and pancreatic juice cytology. Pancreatic juice was collected from 12 pancreatic cancer (PC) and 26 non-PC patients. RCAS1 and CEA levels were measured by using ELISA. RCAS1 expression on surgically resected tissue was immunohistochemically examined for 2 PC patients. By setting the cutoff level of RCAS1 at 10 U/ml and that of CEA at 18.5 μg/ml, sensitivity of RCAS1 was 42% and that of CEA was 50%. On the other hand, sensitivity and specificity increased from 42% and 85% of RCAS1 alone to 75% and 85% in the examination of RCAS1 + CEA + cytology, and the false-negative rate was also reduced to 25% in this combination. Immunohistochemically, a patient with a high RCAS1 level in pancreatic juice had numerous RCAS1-positive tumor cells in the pancreatic juice. We concluded that RCAS1 and CEA measurements together with cytology in pancreatic juice would be a useful combination method for making a differential diagnosis of PC from non-PC.

SUCCESSFUL ENDOSCOPIC EXTRACTION OF A LARGE IMPACTED CHOLEDOCHOLITHIASIS IN THE AMPULLA OF VATER : TWO INTERESTING CASES

In patients with choledocholithiasis, a stone can sometimes become impacted in the ampulla of Vater, potentially resulting in the complications of acute cholangitis and acute pancreatitis. Endoscopic sphincterotomy and needle knife papillotomy are very effective for the removal of an impacted stone in the ampulla of Vater. Dramatic improvement of the symptoms may be expected if these procedures are performed sufficiently early after the occurrence of the impaction. However, depending on the size, site and situation of the impacted stone, we have often encountered difficulties during endoscopic treatment. We encountered two interesting cases of choledocholithiasis with impaction of large stones in the ampulla of Vater. In Case 1, treatment with radial incisions was added to the usual treatment of needle knife papillotomy, because of the large size of the stone, and the combined treatment was effective. In Case 2, a large periampullary choledochoduodenal fistula was created at the ampulla of Vater, and an indwelling double pigtail tube was placed in the ampulla; the stone then discharged via the tube without additional need for endoscopic sphincterotomy or needle knife papillotomy. Our experience in these cases indicates that innovations in treatment according to the situation of the impacted stone may be needed for the treatment of giant impacted stones in the ampulla of Vater.

TRANS‐GASTRIC ENDOSCOPIC DRAINAGE USING A LARGE BALLOON FOR PANCREATIC NECROSIS AND ABSCESS – TWO CASE REPORTS

Reports on endoscopic treatment for pancreatic necrosis and pancreatic abscess have occasionally been published in recent years. Single treatments using endoscopic transpapillary or transumural drainage were originally used, but these were frequently changed to surgical therapy. In recent years, attempts have been made, such as the use of a combination of transmural and transpapillary approaches, the balloon dilatation of the cystgastrostoma, and a daily endoscopic necrosectomy and saline solution lavage, and the treatment results have thus been improved, even though the number of cases is low. We performed transmural endoscopic ultrasonography (EUS)‐guided drainage without a necrosectomy in two cases with pancreatic necrosis and abscess, and treated cases in which a continuous closed lavage using a tube with a large diameter was effective, and we herein report our findings.