Maintenance steroid therapy is associated with decreased risk of malignancy and better prognosis of patients with autoimmune pancreatitis: A multicenter cohort study in Japan.

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.

TOKYO criteria 2024 for the assessment of clinical outcomes of endoscopic biliary drainage.

The consensus-based TOKYO criteria were proposed as a standardized reporting system for endoscopic transpapillary biliary drainage. The primary objective was to address issues arising from the inconsistent reporting of stent outcomes across studies, which has complicated the comparability and interpretation of study results. However, the original TOKYO criteria were not readily applicable to recent modalities of endoscopic biliary drainage such as biliary drainage based on endoscopic ultrasound or device-assisted endoscopy. There are increasing opportunities for managing hilar biliary obstruction and benign biliary strictures through endoscopic drainage. Biliary ablation has been introduced to manage benign and malignant biliary strictures. In addition, the prolonged survival times of cancer patients have increased the importance of evaluating overall outcomes during the period requiring endoscopic biliary drainage rather than solely focusing on the patency of the initial stent. Recognizing these unmet needs, a committee has been established within the Japan Gastroenterological Endoscopy Society to revise the TOKYO criteria for current clinical practice. The revised criteria propose not only common reporting items for endoscopic biliary drainage overall, but also items specific to various conditions and interventions. The term "stent-demanding time" has been defined to encompass the entire duration of endoscopic biliary drainage, during which the overall stent-related outcomes are evaluated. The revised TOKYO criteria 2024 are expected to facilitate the design and reporting of clinical studies, providing a goal-oriented approach to the evaluation of endoscopic biliary drainage.

Dual role of autotaxin as novel biomarker and therapeutic target in pancreatic neuroendocrine neoplasms.

Pancreatic neuroendocrine neoplasms (panNENs) are rare pancreatic neoplasms, and descriptions of treatment remain limited. Autotaxin (ATX) is a secreted autocrine motility factor involved in the production of lysophosphatidic acid (LPA), a lipid mediator that promotes the progression of various cancers. The aim of this study was to clarify the importance of the ATX-LPA axis in panNENs and to confirm its contribution to panNEN progression using clinical data, cell lines, and a mouse model. Serum ATX level was higher in patients with panNEN than in patients with other pancreatic diseases (chronic pancreatitis, pancreatic ductal adenocarcinoma [PDAC], intraductal papillary mucinous neoplasm, autoimmune pancreatitis) and healthy controls, and 61% of clinical specimens stained strongly for ATX. In a case we encountered, serum ATX level fluctuated with disease progression. An in vitro study showed higher ATX mRNA expression in panNEN cell lines than in PDAC cell lines. Cell proliferation and migration in panNEN cell lines were stimulated via the ATX-LPA axis and suppressed by RNA interference or inhibitors. An in vivo study showed that intraperitoneal injection of GLPG1690, an ATX inhibitor, suppressed tumor progression in a xenograft model. These findings revealed that ATX expression is significantly elevated in panNEN and is related to the progression of panNEN. We showed the potential of ATX as a novel biomarker and therapeutic target.

Clinical impact of bile-derived exosomal microRNAs as novel diagnostic and prognostic biomarkers for biliary tract cancers.

Sampling of bile juice during endoscopic retrograde cholangiopancreatography (ERCP) has potential benefit of being amenable to the identification of novel biomarkers in liquid biopsy. This study reports the results of a global investigation of exosomal microRNAs (miRNAs) in bile to identify potential biomarkers for biliary tract cancers (BTCs). Eighty-eight bile samples collected during ERCP (45 BTC and 43 noncancer control samples) were enrolled in this study. Eleven BTC samples and nine control samples were assigned as the discovery set. Exosomes in bile and serum samples were collected using a glass membrane column with size-controlled macroporous glass (MPG), and exosomal miRNA expression profiles were evaluated using comprehensive miRNA microarray analysis (3D-Gene). For validation, exosomal miRNA in the bile samples of 34 BTCs and 34 controls were comprehensively evaluated using 3D-Gene. In the discovery set, eight exosomal miRNAs in bile were identified as significant aberrant expression markers, while no miRNA with aberrant expression in serum was identified. In a comparison of the discovery and validation sets, miR-451a and miR-3619-3p were identified as reproducible upregulated markers, and the combination of the two bile miRNAs showed an excellent area under the curve (0.819) value for diagnosing BTCs. In addition, high miR-3619-3p expression in bile reflects poorer prognosis of BTCs (hazard ratio = 2.89). The MPG-extracted exosomal miRNAs in bile aspirated during ERCP provide a convenient new approach for diagnosing biliary diseases. Bile-derived miRNA analysis with miR-451a and miR-3619-3p represents a potentially valuable diagnostic strategy for identifying BTCs as well as a predictive indicator of BTC prognosis.

Comparison of the long-term outcomes of EUS-guided gallbladder drainage and endoscopic transpapillary gallbladder drainage for calculous cholecystitis in poor surgical candidates: a multicenter propensity score-matched analysis.

BACKGROUND AND AIMS: Although long-term stent placement using endoscopic transpapillary gallbladder drainage (ETGBD) and EUS-guided gallbladder drainage (EUS-GBD) reportedly reduces cholecystitis recurrence, comparative evidence of their safety and efficacy is scarce. This study aimed to examine and compare the long-term utility of EUS-GBD versus that of ETGBD in poor surgical candidates. METHODS: A total of 379 high-risk surgical patients with acute calculous cholecystitis met the eligibility criteria for enrollment in this study. The technical success and adverse events (AEs) were compared between the EUS-GBD and ETGBD groups, and propensity score matching was performed to adjust for differences between the groups. Both groups underwent plastic stent placement, and scheduled stent exchange and removal were not performed in either group. RESULTS: The technical success rate of EUS-GBD was significantly higher than that of ETGBD (96.7% vs 78.9%, P < .001), whereas the early AE rate did not differ significantly between the 2 methods (7.8% vs 8.9%, P = 1.000). The rate of recurrent cholecystitis did not differ significantly (3.8% vs 3.0%, P = 1.000), but the rate of symptomatic late AEs, in addition to cholecystitis, was significantly lower with EUS-GBD than with ETGBD (1.3% vs 13.4%, P = .006). Consequently, the overall late AE rate was significantly lower with EUS-GBD (5.0% vs 16.4%, P = .029). Multivariate analysis revealed that EUS-GBD was associated with a significantly longer time to late AE (hazard ratio, .26; 95% confidence interval, .10-.67; P = .005). CONCLUSIONS: Long-term stent placement via EUS-GBD is a promising potential option for limiting late AEs, including recurrence, in poor surgical candidates with calculous cholecystitis.

Reducing relapse through maintenance steroid treatment can decrease the cancer risk in patients with IgG4-sclerosing cholangitis: Based on a Japanese nationwide study.

OBJECTIVE: IgG4-related sclerosing cholangitis (IgG4-SC) is recognized as a benign steroid-responsive disease; however, little is known about the risk of development of cancer in patients with IgG4-SC and about how to counter this risk. DESIGN: We conducted a retrospective review of the data of 924 patients with IgG4-SC selected from a Japanese nationwide survey. The incidence, type of malignancy, and risk of malignancy in these patients were examined. Then, the standardized incidence ratio (SIR) of cancer in patients with IgG4-SC was calculated. RESULTS: Relapse was recognized in 19.7% (182/924) of patients, and cancer development was noted in 15% (139/924) of patients. Multivariate analysis identified only relapse as an independent risk factor for the development of cancer. In most of these patients with pancreato-biliary cancer, the cancer developed within 8 years after the diagnosis of IgG4-SC. The SIR for cancer after the diagnosis of IgG4-SC was 12.68 (95% confidence interval [CI] 6.89-8.79). The SIRs of cancers involving the biliary system and pancreas were 27.35 and 18.43, respectively. The cumulative survival rate was significantly better in the group that received maintenance steroid treatment (MST) than in the group that did not; thus, MST influenced the prognosis of these patients. CONCLUSION: Among the cancers, the risk of pancreatic and biliary cancers is the highest in these patients. Because of the elevated cancer risk, surveillance after the diagnosis and management to prevent relapse are important in patients with IgG4-SC to reduce the risk of development of cancer.

Long-Term Impact of Endoscopic Gallbladder Stenting for Calculous Cholecystitis in Poor Surgical Candidates: A Multi-center Comparative Study.

BACKGROUND: Although long-term stent placement using endoscopic gallbladder stenting (EGBS) reportedly reduces cholecystitis recurrence in patients unfit to undergo cholecystectomy, its efficacy and safety remain uncertain. AIMS: This study aimed to examine the long-term effect of EGBS in poor surgical candidates of cholecystectomy. METHODS: A total of 528 high-risk surgical patients with acute calculous cholecystitis met this study's eligibility criteria. The technical success and adverse events (AE) were compared between patients who underwent EGBS and those who underwent percutaneous transhepatic gallbladder drainage (PTGBD). Elective stent exchange and removal were not performed after EGBS. The external tube was removed after improvement of cholecystitis following PTGBD. RESULTS: The technical success rate was significantly lower with EGBS compared to PTGBD (75.4% versus 98.7%, P < 0.001), while the early-AE rate did not differ significantly between the two methods (7.7% versus 4.3%, P = 0.146). The 1-, 3-, and 5-year cumulative incidence rates of cholecystitis were 3.8%, 7.2%, and 7.2% with EGBS, and 11.7%, 17.6%, and 30.2% with PTGBD, respectively (P = 0.001). Conversely, those of symptomatic late-AE (except cholecystitis) were 8.2%, 22.7%, and 31.4% with EGBS, and 7.5%, 10.9%, and 13.1% with PTGBD, respectively (P = 0.035). Thus, the 1-, 3-, and 5-year cumulative incidence of overall late-AE was 12.0%, 30.4%, and 40.4% with EGBS, and 19.2%, 28.3%, and 42.5% with PTGBD, respectively (P = 0.649). CONCLUSIONS: Long-term stent placement via EGBS is useful for preventing the recurrence of cholecystitis, but the success rate is low and the frequency of other late-AE increases with the prolongation of the indwelling period.

Various innovative roles for 3-Fr microcatheters in pancreaticobiliary endoscopy.

With the development of newer devices and technical innovations, pancreaticobiliary endoscopy is expanding to assume more advanced therapeutic roles. As with other devices, slimmed-down "3-Fr microcatheters" are considered to be opening new windows toward entirely new therapeutic techniques for various purposes. Our practical experience with a total of 34 consecutive patients in whom 3-Fr microcatheters were applied during pancreaticobiliary endoscopic procedures clarified the potential roles of this instrument in pancreaticobiliary endoscopy. The major benefits of 3-Fr microcatheters involve their slimness and flexibility. Applications of 3-Fr microcatheters could be categorized into three groups according to the characteristics of usage: (1) utilization as a cannulation catheter for peroral digital cholangioscopy (n = 15); (2) selective advancement through deep flexures or severely stenotic ducts (n = 11); or (3) two-devices-in-one-channel technique (n = 8). The microcatheter worked successfully for cannulation of cholangioscopy in all but one case (14/15, 93.3%). For selective advancement, the microcatheter worked for troubleshooting in 9 of 11 cases (81.8%). With the two-devices-in-one-channel technique, the microcatheter proved satisfactory in all cases (8/8, 100%). In total, the microcatheter was successfully maneuvered in 31 of 34 cases (91.1%), following the failure of procedures using conventional endoscopic techniques. In terms of adverse events, cystic duct injury was only observed in two cases (5.8%), who recovered under conservative observation, because its slimness could minimize the damage. We believe that 3-Fr microcatheters offer effective and safe salvage troubleshooting during various endoscopic pancreaticobiliary procedures that face troublesome situations with conventional strategies.

Autotaxin in ascites promotes peritoneal dissemination in pancreatic cancer.

Peritoneal dissemination and malignant ascites in pancreatic ductal adenocarcinoma (PDAC) patients represent a major clinical issue. Lysophosphatidic acid (LPA) is a lipid mediator that modulates the progression of various cancers. Based on the increasing evidence showing that LPA is abundant in malignant ascites, we focused on autotaxin (ATX), which is a secreted enzyme that is important for the production of LPA. This study aimed to elucidate the importance of the ATX-LPA axis in malignant ascites in PDAC and to determine whether ATX works as a molecular target for treating peritoneal dissemination. In a PDAC peritoneal dissemination mouse model, the amount of ATX was significantly higher in ascites than in serum. An in vitro study using two PDAC cell lines, AsPC-1 and PANC-1, showed that ATX-LPA signaling promoted cancer cell migration via the activation of the downstream signaling, and this increased cell migration was suppressed by an ATX inhibitor, PF-8380. An in vivo study showed that PF-8380 suppressed peritoneal dissemination and decreased malignant ascites, and these results were validated by the biological analysis as well as the in vitro study. Moreover, there was a positive correlation between the amount of ATX in ascites and the degree of disseminated cancer progression. These findings demonstrated that ATX in ascites works as a promotor of peritoneal dissemination, and the targeting of ATX must represent a useful and novel therapy for peritoneal dissemination of PDAC.

Pancreatic cancer in patients with autoimmune pancreatitis: A scoping review.

BACKGROUND: Chronic pancreatitis is a known risk factor of pancreatic cancer (PDAC). A similar association has been suggested but not demonstrated for autoimmune pancreatitis (AIP). OBJECTIVE: The aim of our study was to identify and analyse all published cases of AIP and PDAC co-occurrence, focusing on the interval between the diagnoses and the cancer site within the pancreas. METHODS: Relevant studies were identified through automatic searches of the MEDLINE, EMBASE, Scopus, and Web of Science databases, and supplemented by manual checks of reference lists in all retrieved articles. Missing/unpublished data were obtained from the authors of relevant publications in the form of pre-prepared questionnaires. RESULTS: A total of 45 cases of PDAC in AIP patients were identified, of which 12 were excluded from the analysis due to suspicions of duplicity or lack of sufficient data. Thirty-one patients (94%) had type 1 AIP. Synchronous occurrence of PDAC and AIP was reported in 11 patients (33%), metachronous in 22 patients (67%). In the metachronous group, the median period between diagnoses was 66.5 months (2-186) and a majority of cancers (86%) occurred more than two years after AIP diagnosis. In most patients (70%), the cancer originated in the part of the pancreas affected by AIP. CONCLUSIONS: In the literature, there are reports on numerous cases of PDAC in AIP patients. PDAC is more frequent in AIP type 1 patients, typically metachronous in character, and generally found in the part of the pancreas affected by AIP.

One-step versus two-step distal self-expandable metal stent placement: A multicenter prospective randomized trial.

BACKGROUND AND AIM: Two methods of transpapillary covered self-expandable metal stent (SEMS) placement are used for distal malignant biliary obstruction (MBO): after initial drainage by plastic stent (two-step method) and without previous drainage (one-step method). METHODS: In total, 90 patients with unresectable pancreatic cancer and distal MBO were enrolled in this prospective multicenter randomized study and allocated to one-step (n = 45) and two-step (n = 45) groups. The main outcome was the time to recurrent biliary obstruction (TRBO). Secondary outcomes were the rates of early and late adverse events, survival time, the time required for bilirubin level reduction, and cost-effectiveness. RESULTS: The median TRBO did not differ significantly between the one-step and two-step groups (not available vs 314 days, P = 0.134). SEMS migration occurred significantly more frequently in the two-step group (14.3% vs 0%, P = 0.026). No significant difference was observed between groups in early (7.3% vs 14.3%, P = 0.483) or late (12.2% and 11.9%, P = 1) adverse events other than RBO, survival time (P = 0.104), or the median number of days required to reach a bilirubin level considered to be acceptable for chemotherapy administration (<3 mg/dL; P = 0.881). The total costs of stent placement and reintervention were significantly lower in the one-step SEMS group (3347 vs 5465 US dollars, P < 0.001). CONCLUSIONS: The superiority of TRBO with two-step SEMS placement was not demonstrated. One-step SEMS placement might be a promising method from the viewpoints of cost-effectiveness and less invasiveness (UMIN-CTR clinical trial registration number: UMIN000016010).

A hybrid approach for chronic pancreatitis: combination of laparoscopic assisted distal pancreatectomy and open Frey procedure.

BACKGROUND: The treatment of chronic pancreatitis requires a surgical approach in patients who are refractory to medical therapy. During surgical treatment, ductal decompression is required, but a pancreatectomy is necessary for some patients, such as those with severe stenosis of the pancreatic duct. Indeed, suboptimal procedures lead to recurrent pancreatitis. We used a laparoscopic hybrid approach for patients with severe stenosis of the pancreatic duct. In this report, we present the feasibility and outcomes of our approach. METHODS: We selected a laparoscopic approach for the distal pancreatectomy, which is relatively safe and the effect of reducing the length of the wound is substantial. We selected an open approach for the Frey procedure because complete ductal compression has a high risk for injury to the vessels posterior to the pancreas. We recorded the operative outcomes, postoperative complications, and recurrence of pancreatitis. RESULTS: We performed the laparoscopic hybrid approach on 3patients between January and December 2018. There were no major intraoperative complications (Clavien-Dindo classification IIIa or more) and the postoperative course was uneventful in all patients. There were no recurrences of pancreatitis and no postoperative pain in all patients in > 2 years of follow-up. CONCLUSION: Our hybrid method with a focus on complete ductal compression with safety and minimal invasiveness might be the optimal approach for the surgical treatment of chronic pancreatitis that requires a pancreatectomy with the Frey procedure.

Multi-center study of endoscopic revision after side-by-side metal stent placement for malignant hilar biliary obstruction.

BACKGROUND: The recent development of ultra-thin delivery systems, which enable simultaneous insertion of two metal stents, has encouraged wider adoption of side-by-side (SBS) stent placement for malignant hilar biliary obstruction (MHBO). However, the management of stent occlusion after SBS placement has not been well-characterized. This study aimed to examine the outcomes of endoscopic reintervention (E-RI) after SBS placement in patients with MHBO. METHODS: Sixty-seven patients who underwent E-RI for stent occlusion after SBS placement between 2013 and 2020 at three tertiary-care referral centers were investigated. We evaluated the technical success, clinical success, recurrent biliary obstruction (RBO), and adverse events other than RBO rates associated with E-RI. Furthermore, the factors associated with successful E-RI were also evaluated. RESULTS: The technical success and clinical success rates were 79.1% (53/67) and 76.1% (51/67), respectively. Early adverse events other than RBO occurred in 4.5% (3/67) and late events in 3.9% (2/51). The RBO rate after E-RI was 52.9% (27/51), and the median time to RBO after E-RI was 85 days. Common bile duct (CBD) diameter (odds ratio 2.62; 95% confidence interval, 1.37-5.01; P = 0.003) and metastatic disease (odds ratio, 0.11; 95% confidence interval, 0.02-0.64; P = 0.015) were independently correlated with E-RI success in the multivariate analysis. CONCLUSIONS: This study demonstrated that E-RI after SBS placement is technically feasible and safe, but the success rate was significantly lower in patients with narrow CBDs and metastatic diseases. These factors may be useful for the selection of the initial stenting method.

Anti-Allergic Drug Suppressed Pancreatic Carcinogenesis via Down-Regulation of Cellular Proliferation.

Pancreatic cancer is a fatal disease, and thus its chemoprevention is an important issue. Based on the recent report that patients with allergic diseases have a low risk for pancreatic cancer, we examined the potential chemopreventive effect of anti-allergic agents using a hamster pancreatic carcinogenesis model. Among the three anti-allergic drugs administered, montelukast showed a tendency to suppress the incidence of pancreatic cancer. Further animal study revealed a significantly decreased incidence of pancreatic cancer in the high-dose montelukast group compared with controls. The development of the pancreatic intraepithelial neoplasia lesions was also significantly suppressed. The Ki-67 labeling index was significantly lower in pancreatic carcinomas in the high-dose montelukast group than in controls. In vitro experiments revealed that montelukast suppressed proliferation of pancreatic cancer cells in a dose-dependent manner with decreased expression of phospho-ERK1/2. Montelukast induced G1 phase arrest. Conversely, leukotriene D4 (LTD4), an agonist of CYSLTR1, increased cellular proliferation of pancreatic cancer cells with an accumulation of phospho-ERK1/2. In our cohort, pancreatic ductal adenocarcinoma patients with high CYSLTR1 expression showed a significantly unfavorable clinical outcome compared with those with low expression. Our results indicate that montelukast exerts a chemopreventive effect on pancreatic cancer via the LTD4-CYSLTR1 axis and has potential for treatment of pancreatic carcinogenesis.

Efficacy and limitations of the histological diagnosis of type 1 autoimmune pancreatitis with endoscopic ultrasound-guided fine needle biopsy with large tissue amounts.

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.

Guidance for diagnosing autoimmune pancreatitis with biopsy tissues.

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.

Epithelial cyst arising in an intrapancreatic accessory spleen: a case report of robotic surgery and review of minimally invasive treatment.

BACKGROUND: An epithelial cyst in an intrapancreatic accessory spleen (ECIPAS) is rare. We report a case of ECIPAS that was treated with robot-assisted distal pancreatectomy with splenectomy. CASE PRESENTATION: The case was a 59-year-old woman who was referred to our hospital after a pancreatic tail tumor was found on computed tomography prior to surgery for small bowel obstruction at another hospital. A cystic lesion in the pancreatic tail was discovered and evaluated by magnetic resonance imaging and endoscopic ultrasonography. Based on clinical and radiological features, mucinous cystic neoplasm was included in the differential diagnosis. The patient underwent robot-assisted distal pancreatectomy with splenectomy. The postoperative course was uneventful. Pathological evaluation revealed a 20-mm ECIPAS in the pancreatic tail. CONCLUSIONS: If a pancreatic tail tumor is present, ECIPAS should be included in the differential diagnosis. However, preoperative diagnosis is difficult, and a definitive diagnosis is often not obtained until after surgery. Surgery should be minimally invasive. Laparoscopic distal pancreatectomy has become a standard surgical procedure because it is minimally invasive. Robot-assisted surgery is not only minimally invasive, but also advantageous, because it has a stereoscopic magnifying effect and allows the forceps to move smoothly. Robot-assisted distal pancreatectomy may be a good option, when performing surgery for a pancreatic tail tumor.

Intraductal placement of a fully covered metal stent with a long string for distal malignant biliary obstruction without endoscopic sphincterotomy: Prospective multi-center feasibility study.

BACKGROUND: Stent migration and sludge clogging are characteristic problems in biliary covered self-expandable metal stent (SEMS) placement. Intraductal placement without endoscopic sphincterotomy (ES) may help reduce their occurrence. We examined the feasibility of intraductal placement of a covered SEMS with a long string without ES in patients with unresectable distal malignant biliary obstruction (MBO). METHODS: This was a prospective multi-center observational study. Forty patients with distal MBO were enrolled between July 2016 and August 2018. We evaluated recurrent biliary obstruction (RBO), adverse events other than RBO, and reintervention associated with intraductal placement without ES. RESULTS: Both technical and functional success rates were 100% (40/40). The rate of adverse events other than RBO was 5% (2/40). The RBO rate was 33% (13/40), and the median time to RBO was 339 days. RBO was mainly caused by overgrowth on the papillary side, occurring in six patients; all such patients had pancreatic cancer and a distance between the papilla and the stricture of ≤20 mm. Other causes were overgrowth at the hepatic side in two patients and sludge in five patients. No instances of stent migration occurred. Success rates of endoscopic transpapillary reintervention and stent removal using the string were 92% (12/13) and 77% (10/13), respectively. CONCLUSIONS: Intraductal placement without ES using a long-stringed covered SEMS is a promising option for distal MBO. Since overgrowth on the papillary side is frequent, the procedure should be avoided in patients with short distances between the stricture and the papilla. (Clinical Trial Registry: UMIN000023370).

[A Case of Unresectable Hilar Cholangiocarcinoma Resected Curatively Through Effective Response to Neoadjuvant Chemotherapy].

A 60's man came to our hospital for jaundice. Contrast-enhanced CT showed irregular thickening of the hilar bile duct, and the lymph nodes(LN)were swollen from the hilar to the abdominal aorta. These LNs showed similar findings in endoscopic ultrasonography(EUS), and fine needle aspiration cytology(FNA)was performed on the enlarged No.13LN to diagnose LN metastasis of hilar cholangiocarcinoma. Since the peri-aortic LN was also markedly enlarged, it was considered to be metastasis, and was diagnosed as unresectable hilar cholangiocarcinoma with distant LN metastasis. When gemcitabine/cisplatin therapy(GC therapy)was started, tumor markers normalized and LN decreased in 4 months. We performed GC therapy for a total of 12 cycles and did not re-exacerbate. Cholangioscopy revealed that bile duct stenosis at the hilar portion had improved. We have determined that curative resection is possible and performed surgery. We confirmed that No.16b1LN was negative by pathological diagnosis during surgery and performed left hepatic caudate lobectomy, extrahepatic cholangectomy, and biliary reconstruction. Diagnosis was pT2aN1(n8a)M0, fStage ⅢB, and pR0. After surgery, adjuvant chemotherapy with S-1 was continued.

[A Case of Gallbladder Cancer with Para-Aortic Lymph Node Metastasis Successfully Treated by Gemcitabine plus Cisplatin Combination Chemotherapy and Conversion Surgery].

The case is a 59-year-old woman. A medical examination revealed a high CA19-9, she visited a nearby hospital. Abdominal echo showed thickening of the gallbladder wall, and she was referred to our hospital for further examination. EUS-FNA was performed and a biopsy of #12 lymph node revealed undifferentiated cancer, which was diagnosed as gallbladder cancer. FDG-PET showed accumulation of FDG in the gallbladder lumen and swollen lymph nodes around the aorta. Therefore, the cancer was considered unresectable and chemotherapy was performed. FDG-PET was re-examined after 4 courses of gemcitabine plus cisplatin combination chemotherapy. As a result, the lymph node swelling contracted, the accumulation of FDG disappeared, and surgery was scheduled. Extended cholecystectomy and extrahepatic bile duct resection were performed. She was discharged 22 days after the surgery without complications. Histopathological examination showed fibrotic tissue at the gallbladder and lymph nodes, but no residual tumor cells. There are no recurrences 11 months after surgery. Although the prognosis of gallbladder cancer with para-aortic lymph node metastasis is generally poor, it is suggested that conversion surgery with multimodality treatment including preoperative chemotherapy may be a useful therapeutic strategy.