菅野 敦

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. In addition, the resected specimen revealed PDAC, without any features of AIP. After pancreatoduodenectomy, AIP did not recur. The development of AIP in this case could be related to paraneoplastic syndrome.

BACKGROUND: We compared the results of preoperative pancreatic juice cytology (PJC) and final pathological diagnosis after resection in patients who underwent resection of intraductal papillary mucinous neoplasm (IPMN) of the pancreas to determine whether preoperative PJC can help determine therapeutic strategies. METHODS: Of 1130 patients who underwent surgical resection IPMN at 11 Japanese tertiary institutions, the study included 852 patients who underwent preoperative PJC guided by endoscopic retrograde cholangiopancreatography (ERCP). RESULTS: The accuracy of preoperative PJC for differentiation between cancerous and noncancerous lesions were 55% for IPMN overall; 59% for the branch duct type; 49% for the main pancreatic duct type; 53% for the mixed type, respectively. On classifying IPMN according to the diameters of the mural nodule (MN) and main pancreatic duct (MPD), the corresponding values for diagnostic performance were 40% for type 1 (MN ≥5 mm and MPD ≥ 10 mm); 46% for type 2 (MN ≥5 mm and MPD < 10 mm); 61% for type 3 (MN < 5 mm and MPD ≥ 10 mm); 72% for type 4 (MN < 5 mm and MPD < 10 mm), respectively. CONCLUSIONS: PJC in IPMN is not a recommended examination because of its low overall sensitivity and no significant difference in diagnostic performance by type, location, or subclassification. Although the sensitivity is low, the positive predictive value is high, so we suggest that pancreatic juice cytology be performed only in cases where the patient is not sure about surgery.

BACKGROUND/AIM: Malignant ascites is a common condition in patients with terminal cancer. Treatments, such as diuretics, percutaneous drainage of ascites, and abdominal vein shunting have been advocated. However, these treatments have not achieved sufficient palliative effects. Therefore, the development of innovative therapies is mandated, especially for new therapies that require the creation of a fluid simulation of malignant ascites. However, there have been no previous studies on the physical properties of malignant ascites, including viscosity, which are necessary for the development of such a fluid. Therefore, we prospectively investigated the physical properties of malignant ascites. PATIENTS AND METHODS: This single-center, prospective, observational study included 30 patients between November 2021 and January 2023. The primary endpoint was the viscosity of the malignant ascites, and the secondary endpoints included other viscosity studies, biochemical tests, and the presence of malignant cells in the ascites. RESULTS: The median viscosity was 1.105 mPa*S. The viscosity of malignant ascites tended to decrease with increasing temperature, which is common for liquids. Malignant ascites fluid containing malignant cells tended to be more viscous than ascites fluid without malignant cells; furthermore, albumin levels tended to be higher in the former than in the latter. CONCLUSION: Malignant ascites' median viscosity was 1.105 mPa*S. Correlation between viscosity and temperature showed a decreasing trend. These findings contribute valuable insights for future malignant ascites management and device development.

Endoscopic ultrasonography (EUS) is an important diagnostic technique to accurately diagnose diseases originating from organs near the gastrointestinal tract. EUS-guided fine-needle aspiration (FNA) has improved the histopathological diagnosis. EUS-FNA has been further developed over a long period of 40 years. The history of the development of endosonographic scopes, ultrasonographic observation systems, puncture needles, and puncture methods will provide a springboard for future development.

BACKGROUND/OBJECTIVES: The association between autoimmune pancreatitis (AIP) and pancreatic cancer (PC) remains controversial. This study aimed to clarify the long-term prognosis and risk of malignancies in AIP patients in Japan. METHODS: We conducted a multicenter retrospective cohort study on 1364 patients with type 1 AIP from 20 institutions in Japan. We calculated the standardized incidence ratio (SIR) for malignancies compared to that in the general population. We analyzed factors associated with overall survival, pancreatic exocrine insufficiency, diabetes mellitus, and osteoporosis. RESULTS: The SIR for all malignancies was increased (1.21 [95 % confidence interval: 1.05-1.41]) in patients with AIP. Among all malignancies, the SIR was highest for PC (3.22 [1.99-5.13]) and increased within 2 years and after 5 years of AIP diagnosis. Steroid use for ≥6 months and ≥50 months increased the risk of subsequent development of diabetes mellitus and osteoporosis, respectively. Age ≥65 years at AIP diagnosis (hazard ratio [HR] = 3.73) and the development of malignancies (HR = 2.63), including PC (HR = 7.81), were associated with a poor prognosis, whereas maintenance steroid therapy was associated with a better prognosis (HR = 0.35) in the multivariate analysis. Maintenance steroid therapy was associated with a better prognosis even after propensity score matching for age and sex. CONCLUSIONS: Patients with AIP are at increased risk of developing malignancy, especially PC. PC is a critical prognostic factor for patients with AIP. Although maintenance steroid therapy negatively impacts diabetes mellitus and osteoporosis, it is associated with decreased cancer risk and improved overall survival.

Video 1A metalic wire removed by endoscopic submucosal dissection using the pocket-creation method.

A 61-year-old woman was administered 35 cycles of pembrolizumab for the treatment of recurrent endometrial cancer, achieving a complete response. She presented with asymptomatic pancreatic enlargement and elevated hepatobiliary enzymes, but amylase and lipase levels were within the normal ranges. Intrapancreatic bile duct stenosis due to pancreatic enlargement was present, mimicking autoimmune pancreatitis on computed tomography performed before the onset of clinical manifestations. A histological examination of a biopsy specimen showed lymphocyte and plasma cell infiltration with dense fibrosis in the stroma. The patient was successfully treated with oral prednisolone. There were no manifestations of recurrent pancreatitis after tapering the prednisolone dose.

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.

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"). The sub-FNAB specimens were optically cleared using LUCID (IlLUmination of Cleared organs to IDentify target molecules) and analyzed using 3D immunohistochemistry. RESULTS: The median Ki67 index in FNAB, sub-FNAB, and surgical specimens with conventional immunohistochemistry were 1.2% (0.7-5.0), 2.0% (0.5-14.6), and 5.4% (1.0-19.4), respectively. The median Ki67 index in sub-FNAB specimens with tissue clearing was calculated separately using the total number of cells on multiple images ("multiple slice"), with the image of the fewest positive cells ("coldspot"), and with the image of most positive cells ("hotspot"), which were 2.7% (0.2-8.2), 0.8% (0-4.8), and 5.5% (2.3-12.4), respectively. PanNET grade evaluated for the hotspot of the surgical specimens was significantly more consistent with those of the hotspot than multiple images of sub-FNAB specimens (16/17 vs. 10/17, p = 0.015). Hotspot evaluation using 3D immunohistochemistry of the sub-FNAB specimens showed agreement with the assessment of the surgical specimens (Kappa coefficient: 0.82). CONCLUSIONS: Tissue clearing and 3D immunohistochemistry for the Ki67 index can potentially improve the preoperative evaluation of EUS-FNAB specimens of PanNET in routine clinical practice.

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 CA19-9 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. Consequently, the patient was diagnosed with cholangiocarcinoma resembling IgG4-SC after detecting an umbilical metastasis, also known as Sister Mary Joseph's nodule.

＜文献概要＞膵癌早期診断研究会(JEDPAC)でStage 0とStageI膵癌の臨床的な特徴をまとめた.危険因子に関しては,糖尿病やIPMNなどを合併している患者が多かった.受診契機は,他疾患の経過観察中に発見された症例が最も多く症状のない症例が多かった.画像所見に関して,膵管拡張などの副所見が指摘された症例が多かった.また,早期に診断される膵癌の特異的な画像所見として認識されつつある膵の限局的脂肪化は約40%の症例に認められた.また,Stage 0の症例はENPDによる膵液細胞診によって病理学的に診断された症例が多かった.Stage 0とStageIの膵癌の予後は良好であったが,残膵癌に注意する必要があることが明らかになった.さまざまな臨床的な特徴を踏まえ,膵癌が早期に診断され,予後の改善に結びつくことが期待される.

自己免疫性膵炎(AIP)は,画像上,膵腫大と膵管の不整狭細を特徴とする。しかし,内視鏡的逆行性膵胆管造影やMRCPによる膵管像のみでは限局したAIPと膵癌の鑑別診断は困難である。超音波内視鏡(EUS)は,sausage like appearanceやcapsule like rimといった特徴的な画像所見が得られるのみならず,造影EUSを用いた血流の所見やエラストグラフィーによる硬度の変化を得ることによってAIPの診断能向上に寄与する。さらに,EUS下穿刺吸引法(EUS-FNA)を用いたAIPの病理組織学的診断の有用性が報告されている。EUSは,AIPの診断において重要な役割を担っている。(著者抄録)

【背景と目的】この前向き多施設共同研究は,膵癌とその他の膵腫瘍の鑑別におけるティッシュハーモニック(Tissue harmonic endoscopic ultrasonography;TH-EUS)と造影ハーモニックEUS(Contrast-enhanced harmonic endoscopic ultrasonography;CH-EUS)の正診率を比較検討することを目的とした.【方法】2013年8月から2014年12月の間にかけて,固形膵腫瘍の連続症例を前向きに登録した.TH-EUSとCH-EUSの正診率を評価するため,TH-EUSの4所見(境界不明瞭,辺縁不整,内部低エコー,内部エコー不均一)とCH-EUSの4所見(早期相および後期相のそれぞれでhypoenhancement,heterogeneous enhancement)を比較し,各手法のどの所見が最も膵癌の診断に適しているか検討した.また,TH-EUSとCH-EUSにおける膵癌の診断についての観察者間一致度も評価した.【結果】204名の患者が本研究に登録された.膵癌の診断において,エキスパートと非エキスパートによる観察者間一致度は,TH-EUSではそれぞれ0.33-0.50と0.35-0.50,CH-EUSではそれぞれ0.72-0.74と0.20-0.54であった.TH-EUSの所見のうち膵癌の鑑別において最も正診率の高い所見は辺縁不整であり,感度,特異度,正診率はそれぞれ95.0%,42.9%,78.9%であった.CH-EUS所見のうち膵癌の正診率の高い所見は後期相hypoenhancementであり,感度,特異度,正診率はそれぞれ90.8%,74.6%,85.8%であった.CH-EUS(後期相hypoenhancement)の膵癌の正診率は,TH-EUS(辺縁不整)よりも有意に高かった(p<0.001).【結語】CH-EUSはTH-EUSと比較して,膵癌診断能および診断における再現性を向上させた.UMIN(000011124).(著者抄録)

BACKGROUND: Chronic pancreatitis (CP) is defined according to the recently proposed mechanistic definition as a pathological fibro-inflammatory syndrome of the pancreas in individuals with genetic, environmental, and/or other risk factors who develop persistent pathological responses to parenchymal injury or stress. METHODS: The clinical practice guidelines for CP in Japan were revised in 2021 based on the 2019 Japanese clinical diagnostic criteria for CP, which incorporate the concept of a pathogenic fibro-inflammatory syndrome in the pancreas. In this third edition, clinical questions are reclassified into clinical questions, background questions, and future research questions. RESULTS: Based on analysis of newly accumulated evidence, the strength of evidence and recommendations for each clinical question is described in terms of treatment selection, lifestyle guidance, pain control, treatment of exocrine and endocrine insufficiency, and treatment of complications. A flowchart outlining indications, treatment selection, and policies for cases in which treatment is ineffective is provided. For pain control, pharmacological treatment and the indications and timing for endoscopic and surgical treatment have been updated in the revised edition. CONCLUSIONS: These updated guidelines provide clinicians with useful information to assist in the diagnosis and treatment of CP.

BACKGROUND: We attempted to determine the indications and limitations of steroid therapy as the 1st line therapy in patients with autoimmune pancreatitis (AIP) with cyst formation (ACF). METHODS: This Japanese multicenter survey was conducted to examine the merits/demerits of steroid treatment as the initial therapy for ACF. RESULT: Data of a total of 115 patients with ACF were analyzed. Complete remission was achieved in 86% (86/100) of patients who had received steroid treatment, but only 33.3% (5/15) of patients who had not received steroids. Relapse after the remission (n=86) occurred in 7.6% (6/86) of patients who had received steroid therapy, but 40% (2/5) of patients who had not received steroid therapy. Multivariate analysis identified adoption of the wait&watch approach without steroid treatment (odds ratio=0.126, p<0.001) as a significant and independent negative predictor of remission of ACF. As for predictors of relapse, the presence of varix (odds ratio=5.83, p=0.036) was identified as an independent risk factor. CONCLUSION: Steroid therapy plays an important role as 1st line therapy in AIP patients with pancreatic cyst formation, however, varix formation, besides the diameter of the cyst(s), is a risk factor for refractoriness to steroid therapy.

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. Contrast-enhanced harmonic endoscopic ultrasound can contribute to the differential diagnosis of pancreatic tumors.

Yuki and colleagues report a case of successful endoscopic hemostasis of post-papillectomy bleeding with the gel immersion method and an endoscope with an attached balloon and a cylindrical hood. The visual field was improved with gel and maneuverability was improved using the cylindrical hood and the semi-inflating balloon.

症例は57歳男性.検診で膵体部の嚢胞性病変が指摘され,当院を紹介された.造影CTでは膵体部に17mm大の中心部に嚢胞成分を伴う充実性腫瘤が認められた.3年後の造影CTでは,嚢胞成分を伴いながら23mm大に腫瘍径が増大し,MRIでは中心部の嚢胞成分はT1WI,T2WIともに高信号を示し,辺縁は拡散低下を伴う充実成分として観察された.超音波内視鏡検査でも同様に,中心に嚢胞成分を伴う充実性腫瘤として観察された.膵体尾部切除が施行され,病理学的にmixed acinar-neuroendocrine carcinoma(MAcNEC)と診断された.腫瘍中央の嚢胞成分は壊死によるものが疑われ,その周囲にsynaptophysin陽性の領域が,更にその周囲にBCL10,trypsin陽性の領域が分かれて確認された.本症例はMAcNECの発生様式を考察する上で示唆に富む症例であり,文献的考察を加え報告する.(著者抄録)

The histological diagnosis of type 1 autoimmune pancreatitis (AIP) based on the findings obtained by an endoscopic ultrasound-guided fine needle biopsy (EUS-FNB) is feasible, but the diagnostic consistency of this method has not been confirmed. We determined the interobserver agreement among 20 pathologists regarding the diagnosis of type 1 AIP, including the distinction from pancreatic ductal adenocarcinoma (PDAC) using large tissue samples obtained by EUS-FNB. After guidance for diagnosing AIP with biopsy tissues was provided, a round 2 was performed. The median sensitivity and specificity for diagnosing PDAC vs. non-neoplastic diseases were 95.2% and 100%, respectively. In groups of specialists (n = 7) and the generalists (n = 13), Fleiss' к-values increased from 0.886 to 0.958 and from 0.750 to 0.816 in round 2. The concordance was fair or moderate for obliterative phlebitis and storiform fibrosis but slight for ductal lesion of type 1 AIP. Discordant results were due to ambiguous findings and biopsy tissue limitations. Among the specialists, the ratio of cases with perfect agreement regarding the presence of storiform fibrosis increased in round 2, but agreement regarding obliterative phlebitis or ductal lesions was not improved. Although the histological definite diagnosis of type 1 AIP was achieved by most observers in > 60% of the cases, the confidence levels varied. Because some ambiguities exist, the histological diagnostic levels based on the diagnostic criteria of type 1 AIP should not be taken for granted. Guidance is effective for improving accurate PDAC diagnoses (notably by recognizing acinar-ductal metaplasia) and for evaluating storiform fibrosis.

症例は72歳男性.膀胱癌術後の経過観察目的に施行した造影CTにて胆嚢底部の壁肥厚が指摘され当科を受診した.造影CTやMRIでは胆嚢底部に造影効果を示す隆起性病変と連続する壁肥厚が認められた.EUSでは,広基性の隆起性病変における外側高エコー層の不整が認められた.ERCP時の胆汁細胞診から腺癌を認め,拡大胆嚢摘出術が施行された.肉眼所見では大小不同の顆粒状粘膜を伴う壁肥厚性病変と,隆起性病変の一部と考えられる脱落した組織片が確認された.病理所見では肥厚した胆嚢壁と一致して管状腺癌と神経内分泌癌の所見が認められ,混合型神経内分泌癌と診断した.また脱落した組織には腺癌と肉腫が混在していた.胆嚢における腺癌,神経内分泌癌,肉腫が混ずる腫瘍は稀と考えられた.神経内分泌癌と癌肉腫の進展様式のまとめから,混合する腫瘍成分の影響により隆起性病変と壁肥厚性病変が混在する特異的な形態を呈した可能性が示唆された.(著者抄録)

Autoimmune pancreatitis (AIP) is a disease concept that originated in Japan. It is characterized by diffuse pancreatic enlargement and irregular narrowing of the main pancreatic duct. Although the usefulness of the histological diagnosis of AIP using endoscopic ultrasound (EUS)-guided fine-needle aspiration (FNA) and EUS-guided fine-needle biopsy (FNB) has been reported, enhanced diagnostic performance is expected with improvements in tissue collection methods and fine-needle techniques. Guidance for establishing the tissue diagnosis of AIP has been developed and is useful for histological evaluation. Histopathological diagnosis by EUS-FNA/FNB is expected to play a central role in AIP diagnosis in the future.

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. The success rate of reaching the anastomosis or duodenal papilla was significantly lower in pediatric patients than in adult patients (66.7% vs. 88.0%, p < 0.01). The clinical success rate was also significantly lower in pediatric patients (64.9% vs. 80.4%, p = 0.014). The rate of adverse events was significantly higher in pediatric patients than in adults (14.2% vs. 7.7%, p = 0.037). However, if the anastomotic sites were reached in pediatric patients, the treatment was highly successful (97.3%). The time of reaching target site was significantly longer in pediatric patients than in adult patients. This study shows that BEA-ERC in pediatric patients is more difficult than that in adult patients. However, in patients where the balloon enteroscope was advanced to the anastomosis, clinical outcomes comparable to those in adults can be achieved.

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. Recent enhancements in needle biopsy methodologies and technologies have contributed to improvement in the diagnostic efficacy of this technique. The guidance provided in this study for the histological diagnosis of AIP is anticipated to further advance in the histopathological diagnosis of AIP using EUS-guided pancreatic sampling.

An 83-year-old man without specific symptoms was referred to our hospital for further evaluation and treatment of apparent double primary tumors of the cystic duct and common bile duct. Computed tomography showed contrast-enhanced solid tumors in the cystic duct and common bile duct. Magnetic resonance imaging showed that the bile duct tumor was isointense on T1-weighted images and had low intensity on T2-weighted images. In addition, the bile duct tumor showed high intensity on diffusion-weighted images. Endoscopic ultrasonography revealed the tumor of the common bile duct and endoscopic retrograde cholangiopancreatography demonstrated a filling defect in the bile duct. The cystic duct was not identified on endoscopic ultrasonography or endoscopic retrograde cholangiopancreatography. Transpapillary biopsy of the bile duct tumor showed adenocarcinoma. The patient was diagnosed with double primary tumors of the cystic duct and the common bile duct and underwent subtotal stomach-preserving pancreaticoduodenectomy. Microscopic examination with molecular profiling of the tumors revealed a high-grade noninvasive intracholecystic papillary neoplasm of the cystic duct extending into the common bile duct and forming a tubulopapillary neoplasm with invasion of the common bile duct.

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. Compared to the prevalence of other organ cancers in Japan, pancreatic ductal adenocarcinoma ranks seventh based on the number of patients, eighth based on morbidity, and fourth based on the number of deaths, with a continuing increase in the mortality rate. Risk factors for developing pancreatic ductal adenocarcinoma include family history, genetic disorders, diabetes, chronic pancreatitis, and intraductal papillary mucinous neoplasms. An issue that hinders improvement in the prognosis of patients with pancreatic ductal adenocarcinoma is the development of a strategy to identify patients with these risk factors to facilitate detection of the disease at a stage when intervention will improve survival.

OBJECTIVES: This prospective multicenter study aimed to assess and compare the accuracy of tissue harmonic endoscopic ultrasonography (TH-EUS) and contrast-enhanced harmonic endoscopic ultrasonography (CH-EUS) for differentiating pancreatic carcinoma from other pancreatic tumors. METHODS: Consecutive patients with solid pancreatic tumors were prospectively enrolled between August 2013 and December 2014. To assess the accuracy of TH-EUS and CH-EUS, we compared four parameters of TH-EUS (fuzzy edge, irregular periphery, hypoechogenicity, and heterogeneous internal echogenicity) and four parameters of CH-EUS (hypoenhancement and heterogeneous enhancement in the early and late phases, respectively) to investigate which parameter of each method was most suitable to diagnose pancreatic carcinomas. Interobserver agreement and the diagnostic ability of pancreatic carcinoma using TH-EUS and CH-EUS were assessed and compared. RESULTS: A total of 204 patients were enrolled. For the diagnosis of pancreatic carcinoma, interobserver agreement by experts and nonexperts was 0.33-0.50 and 0.35-0.50 for TH-EUS, respectively, and 0.72-0.74 and 0.20-0.54 for CH-EUS, respectively. Irregular periphery was the most accurate diagnostic parameter among TH-EUS findings for differentiating pancreatic carcinomas, with sensitivity, specificity, and accuracy of 95.0%, 42.9%, and 78.9%, respectively. Late phase hypoenhancement was the most accurate diagnostic parameter among CH-EUS findings for differentiating pancreatic carcinomas, with sensitivity, specificity, and accuracy of 90.8%, 74.6%, and 85.8%, respectively. The accuracy of CH-EUS (late phase hypoenhancement) for diagnosis of pancreatic carcinoma was significantly higher than that of TH-EUS (irregular periphery) (p < 0.001). CONCLUSION: In comparison with TH-EUS, CH-EUS increased the diagnostic ability and reproducibility for the diagnosis of pancreatic carcinoma. UMIN (000011124).

Background/Aims: The aim of this study was to evaluate the safety and efficacy of partially covered self-expandable metallic stents (PCSEMS) in patients undergoing neoadjuvant chemo(radio) therapy (NAC) for pancreatic cancer (PC). Methods: This was a prospective multicenter study to evaluate the safety and efficacy of PCSEMS in patients receiving NAC for resectable and borderline resectable PC. The primary endpoint was the rate of recurrent biliary obstruction (RBO). Results: Twenty-six patients with PC (three with resectable PC and 23 with borderline resectable PC) who underwent NAC at seven Japanese centers were included in the analysis. Both the technical and functional success rates of PCSEMS placement were 100%. Early stent-related complications were observed in three patients (11.5%): mild pancreatitis (n=2) and mild liver abscess (n=1). The median time to surgery or palliation was 4.0 months. Surgical resection was eventually performed in 73.1% of patients, and stent removal during surgery was successful in all patients. RBO was observed in nine patients (34.6%): seven with stent occlusion, one with kinking and one with migration. The RBO rates in resected cases and nonresected cases were 36.8% and 28.6%, respectively. Conclusions: Biliary drainage by PCSEMS was safe and feasible in patients undergoing NAC for resectable and borderline resectable PC.

BACKGROUND AND AIMS: Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) is used for the histopathological diagnosis of any type of gastrointestinal disease. Few adverse events are experienced with this procedure; however, the actual rate of adverse events remains unclear. This study aimed to clarify the current status of cases that experienced adverse events related to the EUS-FNA procedure used for histopathologic diagnoses. METHODS: A retrospective analysis of cases with EUS-FNA-related adverse events in Japanese tertiary centers was conducted by assessing the following clinical data: basic case information, FNA technique, type of procedural adverse events, and prognosis. RESULTS: Of the 13,566 EUS-FNA cases overall, the total number of cases in which adverse events related to EUS-FNA occurred was 234. The incidence of EUS-FNA-related adverse events was ~1.7%. Bleeding and pancreatitis cases accounted for ~49.1% and 26.5% of all adverse events, respectively. Bleeding was the most common adverse event with only seven cases requiring blood transfusion. In cases with neuroendocrine tumors, pancreatitis was the most frequent adverse event. Needle tract seeding because of EUS-FNA was observed during the follow-up period in only ~0.1% of cases with pancreatic cancer. There was no mortality because of adverse events caused by EUS-FNA. CONCLUSIONS: This study revealed that the adverse events-related EUS-FNA for histopathologic diagnoses were not severe conditions, and had low incidence.

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. While stenosis of the bile duct in IgG4-SC is characterized by longer-length stenosis than in cholangiocarcinoma, differentiation based on bile duct imaging alone is challenging. Endoscopic ultrasound (EUS) can characterize hypoechoic enlargement of the pancreas or bile duct wall thickening in AIP and IgG4-SC, and diagnosis using elastography and contrast-enhanced EUS are being evaluated. The utility of EUS-guided fine needle aspiration for the histological diagnosis of AIP has been reported and is expected to improve diagnostic performance for AIP. Findings in the bile duct wall from endoscopic retrograde cholangiopancreatography followed by intraductal ultrasonography are useful in differentiating IgG4-SC from cholangiocarcinoma. Diagnoses based on endoscopic ultrasonography play a central role in the diagnosis of AIP.

症例は29歳男性.心窩部痛を主訴に近医受診し,血液生化学検査で肝胆道系酵素値の上昇と黄疸を認めた.造影CTで肝内胆管の拡張と肝門部胆管に腫瘍性病変を認めるとともに,MRCPで膵・胆管合流異常を認めた.腫瘍より乳頭側の胆管に拡張を認めず,非拡張型膵・胆管合流異常に合併した肝門部胆管癌(BismuthII)と診断し,肝拡大左葉切除・尾状葉切除・肝外胆管切除術を施行した.切除標本で肝門部に結節浸潤型の病変を認め,病理組織学的検討より浸潤癌部に連続する乳頭側の胆管上皮にbiliary intraepithelial neoplasia(BilIN)病変を認めた.非拡張型の膵・胆管合流異常では,胆嚢癌が高率に発症するとされるが,胆管癌の発症は多くない.本症例は30歳未満と若年発症した胆管癌症例であるが,職業性胆管癌の可能性は示唆されず,その発癌に膵・胆管合流異常が深く関与していたと考えられる.(著者抄録)

BACKGROUND/OBJECTIVES: Pancreatic neuroendocrine carcinoma (PanNEC)-G3 often presents along with genetic abnormalities such as KRAS, RB1, and TP53 mutations. However, the association between these genetic findings and response to chemotherapy and prognosis has not been clarified. This study aimed to clarify the clinicopathological features of PanNEC-G3. METHODS: We performed a subgroup analysis of the Japanese PanNEN-G3 study (multicenter, retrospective study), which revealed that Rb loss and KRAS mutation were predictors of the response to platinum-based regimen in PanNEN-G3. We re-classified WHO grades of PanNENs using the 2017 WHO classification and then analyzed the clinicopathological features and prognostic factors in 49 patients with PanNEC-G3. RESULTS: The rates of Rb loss and KRAS mutation in PanNEC-G3 were 54.5% and 48.7%, respectively. Patients with Rb loss and/or KRAS mutation showed a higher response rate to first-line platinum-based regimen than those without Rb loss or KRAS mutation (object response rate 70.0% vs 33.3%, odds ratio 9.22; 95% CI 1.26-67.3, P = 0.029), but tended to have shorter overall survival rates than those without Rb loss or KRAS mutation (median 239 vs 473 days, hazard ratio 2.11; 95% CI 0.92-4.86, P = 0.077). CONCLUSIONS: Patients with PanNEC-G3 have varied clinical outcomes for platinum-based regimen. When grouped based on Rb loss and KRAS mutation, there seemed to be two groups with distinct prognoses and responses to the platinum-based regimen. PanNEC-G3 could, therefore, be classified into two distinct groups based on immunohistochemical and genetic findings.

The biopsy-based diagnosis of autoimmune pancreatitis (AIP) is difficult but is becoming imperative for pathologists due to the increased amount of endoscopic ultrasound-guided biopsy tissue. To cope with this challenge, we propose guidance for the biopsy diagnosis of type 1 AIP. This guidance is for pathologists and comprises three main parts. The first part includes basic issues on tissue acquisition, staining, and final diagnosis, and is intended for gastroenterologists as well. The second part is a practical guide for diagnosing type 1 AIP based on the AIP clinical diagnostic criteria 2018. Inconsistent histological findings, tips for evaluating IgG4 immunostaining and key histological features including the ductal lesion and others are explained. Storiform fibrosis and obliterative phlebitis are diagnostic hallmarks but are sometimes equivocal. Storiform fibrosis is defined as spindle-shaped cells, inflammatory cells and fine collagen fibers forming a flowing arrangement. Obliterative phlebitis is defined as fibrous venous obliteration with inflammatory cells. Examples of each are provided. The third part describes the differentiation of AIP from pancreatic ductal adenocarcinoma (PDAC), focusing on histological features of acinar-ductal metaplasia in AIP, which is an important mimicker of PDAC. This guidance will help standardize pathology reports of pancreatic biopsies for diagnosing type 1 AIP.

BACKGROUND/OBJECTIVES: This paper is part of the international consensus guidelines on chronic pancreatitis, presenting for interventional endoscopy. METHODS: An international working group with experts on interventional endoscopy evaluated 26 statements generated from evidence on 9 clinically relevant questions. The Grading of Recommendations Assessment, Development, and Evaluation approach was used to evaluate the level of evidence. To determine the level of agreement, a nine-point Likert scale was used for voting on the statements. RESULTS: Strong consensus was obtained for 15 statements relating to nine questions including the recommendation that endoscopic intervention should be offered to patients with persistent severe pain but not to those without pain. Endoscopic decompression of the pancreatic duct could be used for immediate pain relief, and then offered surgery if this fails or needs repeated endoscopy. Endoscopic drainage is preferred for portal-splenic vein thrombosis and pancreatic fistula. A plastic stent should be placed and replaced 2-3 months later after insertion. Endoscopic extraction is indicated for stone fragments remaining after ESWL. Interventional treatment should be performed for symptomatic/complicated pancreatic pseudocysts. Endoscopic treatment is recommended for bile duct obstruction and afterwards surgery if this fails or needs repeated endoscopy. Surgery may be offered if there is significant calcification and/or mass of the pancreatic head. Percutaneous endovascular treatment is preferred for hemosuccus pancreaticus. Surgical treatment is recommended for duodenal stenosis due to chronic pancreatitis. CONCLUSIONS: This international expert consensus guideline provides evidenced-based statements concerning indications and key aspects for interventional endoscopy in the management of patients with chronic pancreatitis.

PURPOSE: To clarify the usefulness of cancer-related inflammation, hypermetabolism, and subsequent host malnutrition biomarkers for predicting the histological grades of intraductal papillary mucinous neoplasms of the pancreas (IPMNs). METHODS: The systemic immune-inflammation index (SII), prognostic nutritional index (PNI), and maximum standardized uptake value (SUVmax) on fluorodeoxyglucose-positron emission tomography were compared across 171 resected IPMN cases of different histological grades. The diagnostic performance of each marker and of their combinations for predicting IPMN with high-grade dysplasia (HGD)/associated invasive carcinoma (INV) was also tested. RESULTS: Of the 171 IPMNs, the IPMN cases with HGD showed significantly higher values of SII (median 406 vs. 340; P = 0.041) and SUVmax (median 2.5 vs. 2.0; P = 0.001) than those with low-grade dysplasia (LGD). On a multivariate analysis, the SII and SUVmax were both independent markers for predicting HGD/INV. A combination analysis including the tumor- and host-derived markers in combination with imaging findings showed an improved diagnostic performance (area under the curve 0.824; sensitivity 75.9%; specificity 80.0%). CONCLUSIONS: The combination of multiple markers of host-derived inflammation and tumor-derived focal hypermetabolism can serve as a predictor for the presence of HGD/INV.

All gastrointestinal endoscopic procedures have a high risk of aerosol contamination of the coronavirus disease 2019 (COVID-19) to endoscopists, nurses, and healthcare assistants. Given the current pandemic situation of COVID-19, the Japan Gastroenterological Endoscopy Society issued the recommendation for gastrointestinal (GI) endoscopy based on the status of COVID-19 as of April 9, 2020, in Japan: (i) indications for GI endoscopy in the pandemic of COVID-19; (ii) practical protective equipment for medical personnel depending on the risk for COVID-19; (iii) preprocedural management, such as pharyngeal local anesthesia using lidocaine spray which has a potential to generate the aerosols; (iv) ideal settings of the endoscopy room including the numbers of the staff and the patients; (v) postprocedural management, such as undressing and follow-up of the patients, as well as the involved staff, were documented to fit the practical scenarios in GI endoscopy, with the available data in Japan and the world. We believe that certain measures will prevent further spread of COVID-19.

Some situations may require endoscopy during the COVID-19 (Coronavirus Disease 2019) pandemic. Here, we describe the necessary precautions in the form of clinical questions and answers (Q&A) regarding the safe deployment of gastrointestinal endoscopy in such situations while protecting endoscopy staff and patients from infection. Non-urgent endoscopy should be postponed. The risk of infection in patients should be evaluated in advance by questionnaire and body temperature. The health of staff must be checked every day. Decisions to employ endoscopy should be based on the institutional conditions and aims of endoscopy. All endoscopic staff need to wear appropriate personal protective equipment (PPE). The endoscope and other devices should be cleaned and disinfected after procedures in accordance with the relevant guidelines. Optimal management of the endoscopy unit is required. Endoscopy for infected patients or those with suspected infection demands exceptional caution. When a patient who undergoes endoscopy is later found to have COVID-19, the members of staff involved are considered exposed to the virus and must not work for at least 14 days if their PPE is considered insufficient. When PPE resources are limited, some equipment may be used continuously throughout a shift as long as it is not contaminated. Details of the aforementioned protective measures are described.

OBJECTIVES: We examined the efficacy and limitations of acquiring large specimens by endoscopic ultrasound-guided fine needle biopsy (EUS-FNB) for diagnosing type 1 autoimmune pancreatitis (AIP). METHODS: Patients from 12 institutions with non-neoplastic diseases or pancreatic ductal adenocarcinoma (PDAC) with large EUS-FNB specimens were investigated. Slides stained with hematoxylin-eosin, elastic, IgG4, and IgG stains were evaluated. The IgG4- and IgG-positive cell numbers were counted in three foci. The diagnoses were based on the Japan Pancreas Society 2011 (JPS 2011) criteria and the International Consensus Diagnostic Criteria (ICDC). RESULTS: We analyzed 85 non-neoplastic (definite type 1 AIP in 73/85 based on the ICDC) cases and 64 PDAC cases. IgG4-positive cells were numerous (>10 in 85.9%), and the IgG4/IgG ratios were high (>40% in 81.2%). Plasma cell crushing by an artifact caused unsuccessful immunostaining, notably in smaller samples. Tissue lengths were an important factor for the presence of storiform fibrosis and obliterative phlebitis, but storiform fibrosis was equivocal even in large tissues. A definite or possible histological diagnosis was achieved in 45.9% (39/85) and 41.2% (35/85), respectively, and contributed to the definite final diagnosis of type 1 AIP in 33.3% (ICDC) and 55.6% (JPS 2011) in cases with segmental/focal lesions. In the PDAC group, >10 IgG4-positive cells was rare (2/58), but elastic stains revealed fibrous venous occlusions in 10.3% (6/58). CONCLUSIONS: EUS-FNB with large tissue amounts was useful for diagnosing type 1 AIP, notably by facilitating successful IgG4 immunostaining, but definite diagnosis may not be achieved even in cases with large specimens.

A 58-year-old man was referred for obstructive jaundice. Imaging modalities revealed the presence of multiple pancreatic tumors and the stenosis of the middle common bile duct due to a hypoenhanced localized tumor. The multiple pancreatic tumors were histopathologically diagnosed as autoimmune pancreatitis by endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA). To differentiate between IgG4-related sclerosing cholangitis (IgG4-SC) and cholangiocarcinoma, we diagnosed the biliary tumor as IgG4-SC by EUS-FNA because of insufficient pathological materials obtained in a transpapillary manner. We herein report a case of IgG4-SC diagnosed by EUS-FNA.