Relapse and side effects of steroid therapy beyond 3 years in autoimmune pancreatitis: A multicenter retrospective study.

BACKGROUND: The impact of extended steroid administration on patients with autoimmune pancreatitis after a 3-year maintenance period remains poorly understood. This study analyzed the advantage and disadvantage of continuing steroid therapy beyond 3 years. METHODS: In this retrospective multicenter study across 17 institutions, patients who successfully completed 3 years of maintenance therapy without experiencing relapse were categorized into two groups: the maintenance therapy discontinuation group, who discontinued steroid therapy after the initial 3-year period, and maintenance therapy continuation group, who continued steroid therapy beyond 3 years. The cumulative relapse rate after 3 years of maintenance therapy was the primary outcome. Relapse predictors were compared using the Gray test for cumulative relapse incidence by specific factor. RESULTS: Of 211 patients, 105 experienced no relapse during the 3-year maintenance therapy and were divided into two groups: 69 in the maintenance therapy discontinuation group and 36 in the maintenance therapy continuation group. The relapse rate was lower in the maintenance therapy continuation group than in the maintenance therapy discontinuation group (P = 0.035). Predictors of relapse after 3 years included cessation of maintenance therapy (hazard ratio [HR] = 3.76; 95 % confidence interval [CI] = 1.07-13.3, P = 0.040) and renal involvement (HR = 2.88; 95 % CI = 1.04-7.99, P = 0.042). The maintenance therapy continuation group showed a significantly higher prevalence of macrovascular complications, compared with the maintenance therapy discontinuation group (P = 0.005). CONCLUSIONS: Cessation of steroid maintenance therapy and renal involvement were predictors of relapse after 3 years of maintenance therapy. However, the long-term use of steroids may increase the risk of macrovascular complications.

Comprehensive Analysis of Molecular Biologic Characteristics of Pancreatic Ductal Adenocarcinoma Concomitant with Intraductal Papillary Mucinous Neoplasm.

BACKGROUND: Pancreatic ductal adenocarcinoma (PDAC) concomitant with intraductal papillary mucinous neoplasm (IPMN) is defined as PDAC occurring apart from IPMN. This study comprehensively investigated the molecular biologic characteristics of PDAC concomitant with IPMN in major genetic alterations, tumor microenvironment, and prognosis by contrast with those of conventional PDAC. METHODS: The study retrospectively reviewed the data of 158 surgically resected PDAC patients. The driver gene alteration status (KRAS, TP53, CDKN2A, SMAD4, and GNAS) together with the immune and fibrotic status in tumor was evaluated. The prognosis of PDAC concomitant with IPMN and that of conventional PDAC also were compared. RESULTS: No statistically significant difference was found between PDAC concomitant with IPMN and conventional PDAC in the alteration frequency analysis of the major driver genes and the immune and fibrotic status in the tumor microenvironment. Overall survival and disease-free survival between patients who had PDAC concomitant with IPMN and those who had conventional PDAC did not show statistically significant differences in propensity-matched subjects. Furthermore, the co-existence of IPMN was not a poor prognostic factor in the multivariable-adjusted Cox proportional hazards model (hazard ratio, 0.95; 95 % confidence interval, 0.51-1.78). CONCLUSIONS: In this study, PDAC concomitant with IPMN had tumor characteristics similar to those of conventional PDAC in terms of the major driver gene alterations, tumor microenvironment, and prognosis.

[A case of rectovaginal metastasis 6 years after initial resection of extra-gastrointestinal stromal tumor of vulvar origin].

A 53-year-old woman who had undergone excision of KIT-positive extra-gastrointestinal stromal tumor (EGIST) of the vulva 6 years ago presented to our hospital due to a positive fecal occult blood test. Colonoscopy revealed a submucosal tumor in the rectum ventral side. In addition, computed tomography and magnetic resonance imaging revealed a tumor in the rectovaginal septum. For diagnostic and therapeutic purposes, the tumor was resected via the perineal approach. The resected specimen analysis revealed a KIT-positive gastrointestinal stromal tumor (GIST). Following immunopathological and genetic mutation identifications, GIST of the rectovaginal septum from vulva EGIST metastasis was diagnosed. It is important to consider primary GIST and metastatic GIST as differential diagnoses in the case of a rectal submucosal tumor detected by endoscopy.

Evaluation of efficacy of pancreatic juice cytology for risk classification according to international consensus guidelines in patients with intraductal papillary mucinous neoplasm; a retrospective study.

OBJECTIVES: Pancreatic juice cytology (PJC) for intraductal papillary mucinous neoplasm (IPMN) is a possible tool to enhance preoperative diagnostic ability by improving risk classification for malignant IPMN, but its efficacy is controversial. This study evaluated the efficacy of PJC for risk classification according to international guidelines. METHODS: We retrospectively analyzed 127 IPMN patients who underwent endoscopic retrograde cholangiopancreatography (ERCP) preoperatively. PJC was performed in 125 of the 127 cases. High-risk stigmata (HRS, n = 57), worrisome features (WF, n = 64), and other characteristics (n = 6) were classified according to the 2017 international guidelines. RESULTS: Among the 127 IPMN patients, 71 (55.9%) had malignant IPMN (invasive and non-invasive intraductal papillary mucinous carcinoma). The accuracy of WF for classifying malignant IPMN was increased by the addition of PJC, but the accuracy of HRS was not (WF to WF + PJC: 33.1% [42/127] to 48.8% [61/125], HRS to HRS + PJC: 65.4% [83/127] to 52.8% [66/125]). Post-ERCP pancreatitis (PEP) occurred in 32 (25.2%) of 127 IPMN patients. Severe PEP was not detected. Significant risk factors for PEP were female sex, obesity, and endoscopic naso-pancreatic drainage (ENPD) (P = .03, P = .0006, and P = .02, respectively). In patients with ENPD tube placement, a main pancreatic duct size of <5 mm was a significant risk factor for PEP (P = .02). CONCLUSION: PJC could increase the accuracy of WF for classifying malignant IPMN. The additive effect of PJC for risk classification may be limited, however, and it is not recommended for all IPMN cases due to the high frequency of PEP.

Significance of pancreatic calcification on preoperative computed tomography of intraductal papillary mucinous neoplasms.

BACKGROUND AND AIM: Chronic pancreatitis is a risk factor for pancreatic cancer. Pancreatic calcification is a characteristic of chronic pancreatitis; however, its significance for intraductal papillary mucinous neoplasm (IPMN) oncogenesis remains unknown. Therefore, we investigated the relationship between pancreatic calcification and invasive IPMN. METHODS: This study included 157 patients who underwent resection for IPMN between April 2001 and October 2016 (intraductal papillary mucinous adenoma, n = 76; noninvasive intraductal papillary mucinous carcinoma [IPMC], n = 32; and invasive IPMC, n = 49). We divided the subjects on the basis of the presence/absence of pancreatic calcification on preoperative computed tomography (CT). The factors associated with pancreatic calcification were investigated in univariate analyses. Then, multivariate logistic regression analyses of the relationship between pancreatic calcification and invasive IPMC (after adjusting for clinical or imaging characteristics) were conducted. RESULTS: Preoperative CT revealed pancreatic calcification in 17.2% (27/157) of the resected IPMN. In the univariate analyses, jaundice, high serum carbohydrate antigen 19-9 levels, and invasive IPMC were significantly associated with pancreatic calcification (4/27 [14.8%] vs 4/130 [3.1%], 0.01; 12/27 [44.4%] vs 31/130 [23.8%], 0.03; and 15/27 [55.6%] vs 34/130 [26.2%], 0.001, respectively). Pancreatic calcification was significantly associated with invasive IPMC (multivariate odds ratio = 2.88, 95% confidence interval [95% CI] = 1.15-7.21, 0.03, adjusted for clinical characteristics; odds ratio = 5.50, 95% CI = 1.98-15.3, 0.001, adjusted for imaging characteristics). CONCLUSIONS: Pancreatic calcification on CT is associated with invasive IPMC. Pancreatic calcification might be a predictor of invasive IPMC.

Pancreatic inflammation and atrophy are not associated with pancreatic cancer concomitant with intraductal papillary mucinous neoplasm.

BACKGROUND: Inflammation-induced carcinogenesis in pancreatic ductal adenocarcinoma (PDAC) has been reported; however, its involvement in PDAC with intraductal papillary mucinous neoplasm (IPMN) remains unclear. We herein investigated the relationship between pancreatic atrophy and inflammation and the incidence of PDAC concomitant with IPMN. METHODS: This study included 178 consecutive patients who underwent surgical resection for PDAC with IPMN (N = 21) and IPMN (N = 157) between April 2001 and October 2016. A multivariable logistic regression analysis was conducted to assess the relationship between pancreatic inflammation and atrophy and the incidence of PDAC concomitant with IPMN, with adjustments for clinical characteristics and imaging features. Pathological pancreatic inflammation and atrophy were evaluated in resected specimens. RESULTS: High degrees of pancreatic inflammation and atrophy were not associated with the incidence of PDAC with IPMN (multivariable odds ratio [OR] = 0.5, 95% confidence interval [CI] = 0.07 to 3.33, P = .52, adjusted by clinical characteristics, OR = 0.9, 95% CI = 0.10 to 5.86, P = .91, adjusted by imaging studies; OR = 0.2, 95% CI = 0.009 to 1.31, P = .10, adjusted by clinical characteristics, OR = 0.2, 95% CI = 0.01 to 1.43, P = .12, adjusted by imaging studies, respectively). CONCLUSIONS: Pancreatic inflammation and atrophy were not associated with pancreatic cancer concomitant with IPMN.

Multifocal cysts and incidence of pancreatic cancer concomitant with intraductal papillary mucinous neoplasm.

OBJECTIVES: The present study was conducted in order to elucidate the relationship between the number of cyst-existing regions and incidence of pancreatic ductal adenocarcinoma (PDAC) concomitant with intraductal papillary mucinous neoplasm (IPMN), which currently remains unclear. METHODS: Subjects comprised 141 patients undergoing resection for IPMN (Non-invasive IPMN (IPMN with low-to high-grade dysplasia): N = 94, invasive IPMN: N = 31, and PDAC concomitant with IPMN: N = 16) between November 2000 and February 2017. A logistic regression analysis was performed to assess the relationship between the number of cyst-existing regions (one region/two or more regions) and incidence of PDAC concomitant with IPMN, adjusted by clinical characteristics. Cyst-existing regions were defined by the number of anatomical parts of the pancreas: the head/body/tail of the pancreas. RESULTS: Multiple cyst-existing regions (two or more regions) correlated with the incidence of PDAC concomitant with IPMN (PDAC concomitant with IPMN in one region vs. two or more regions: 3/66 vs. 13/75, multivariable odds ratio [OR] = 4.11, 95% confidence interval [CI] = 1.22 to 18.8, P = 0.02). In contrast, multiple cyst-existing regions did not correlate with the incidence of IPMN (invasive IPMN in one region vs. two or more regions: 13/66 vs. 18/75, OR = 1.19, 95% CI = 0.52 to 2.76, P = 0.67). CONCLUSIONS: Multifocal cysts correlated with the incidence of PDAC concomitant with IPMN, and may be a high-risk factor for PDAC concomitant with IPMN.

Randomised controlled, patient-blinded, multicentre, superiority trial to evaluate the efficacy of the line-attached sheath-type traction device for endoscopic submucosal dissection in patients with superficial gastric neoplasms.

INTRODUCTION: EndoTrac is a line-attached sheath-type traction device that enables us to control the direction and the force of traction during endoscopic submucosal dissection (ESD). The efficacy of EndoTrac for gastric ESD has not been fully verified. METHODS AND ANALYSIS: The G-Trac study is a multicentre (nine general hospitals and two university hospitals in Japan) collaborative trial assessing the efficacy of EndoTrac for gastric ESDs. Patients with superficial gastric neoplasms will be enrolled and randomly assigned to undergo either conventional ESD or EndoTrac ESD. Allocation will be stratified according to tumour location, operator experience and tumour diameter at an allocation rate of 1:1. The type of endoknife used will be confirmed before randomisation. The primary outcome, procedure time, will be compared between the groups in both intention-to-treat and per-protocol analyses using the Wilcoxon rank sum test. The efficacy-related, safety-related and device-related outcomes will be assessed in the secondary analysis. The planned sample size of the 142 patients in the two groups will enable us to detect a difference with a power of 80% by using the Wilcoxon rank sum test, assuming an effect size of 0.54, asymptotic relative efficiency of 0.864 and a two-sided type 1 error rate of 5%. ETHICS AND DISSEMINATION: This trial was approved by the certified review board of Kobe University (22 December 2022). The results from this trial will be disseminated through peer-review journals, presentations at national and international conferences, and data sharing with other researchers. TRIAL REGISTRATION NUMBER: jRCT1052220166.

Pancreatic injury in patients treated with immune checkpoint inhibitors: a retrospective multicenterstudy.

BACKGROUND: Immune checkpoint inhibitor-related pancreatic injury (ICI-PI) is a rare occurrence, which has not been reported in detail. We conducted a retrospective multicenter study to determine the clinical characteristics, risk factors, and treatment of ICI-PI. METHODS: We reviewed the medical records of patients who received ICIs for malignant tumors between April 2014 and April 2019 at 16 participating hospitals. Patients with elevated pancreatic enzymes or pancreatitis were identified and classified using the Common terminology Criteria for Adverse Events (CTCAE) ver.5.0). The number of patients with pancreatic enzyme elevation was determined and those with pancreatic enzyme elevation of ≥ grade 3 according to CTCAE ver.5.0, or pancreatitis underwent detailed analysis for ICI-PI. RESULTS: The study enrolled 1069 patients. Nineteen patients (1.8%) had ICI-PI, 5 (0.5%) of whom also had pancreatitis. Four patients had mild pancreatitis, whereas 1 patient had severe pancreatitis, culminating in death. Steroid therapy was administered to 7 of 19 patients, which led to ICI-PI improvement in 5 patients. On the other hand, ICI-PI improved in 9 of 12 patients who were not administered steroid therapy. Six of the 14 patients with ICI-PI improvement were rechallenged with ICI, and ICI-PI relapse occurred in only 1 patient (16.7%), which improved with ICI discontinuation and steroid therapy. CONCLUSIONS: ICI-PI is a rare occurrence, with a low incidence of pancreatitis, which followed a very serious course in one patient. Although the benefit of steroid therapy for ICI-PI is unclear, ICI rechallenge is acceptable after improvement of ICI-PI without pancreatitis.

Temporal progression of pancreatic cancer computed tomography findings until diagnosis: A large-scale multicenter study.

BACKGROUND: Focal parenchymal atrophy and main pancreatic duct (MPD) dilatation have been identified as early signs of pancreatic ductal adenocarcinoma. However, limited evidence exists regarding their temporal progression due to previous study limitations with restricted case numbers. OBJECTIVE: To ascertain a more precise frequency assessment of suspicious pancreatic ductal adenocarcinoma findings as well as delineate the temporal progression of them. METHODS: A multicenter retrospective study was conducted on patients diagnosed with pancreatic ductal adenocarcinoma between 2015 and 2021. We included patients who had undergone at least one computed tomography (CT) scan ≥6 months before diagnosing pancreatic ductal adenocarcinoma. The temporal progression of suspicious pancreatic ductal adenocarcinoma findings on CT was investigated. RESULTS: Out of 1832 patients diagnosed with pancreatic ductal adenocarcinoma, 320 had a previous CT before their diagnosis. Suspicious pancreatic ductal adenocarcinoma findings were detected in 153 cases (47.8%), with focal parenchymal atrophy (26.6%) being the most common followed by MPD dilatation (11.3%). Focal parenchymal atrophy was the earliest detectable sign among all suspicious findings and became visible on average 2.7 years before diagnosis, and the next most common, MPD dilatation, 1.1 years before diagnosis. Other findings, such as retention cysts, were less frequent and appeared around 1 year before diagnosis. Focal parenchymal atrophy followed by MPD dilatation was observed in 10 patients but not in reverse order. Focal parenchymal atrophy was more frequently detected in the pancreatic body/tail. No significant relationship was found between the pathological pancreatic ductal adenocarcinoma differentiation or tumor stage and the time course of the CT findings. All cases of focal parenchymal atrophy progressed just prior to diagnosis, and the atrophic area was occupied by tumor at diagnosis. Main pancreatic duct dilatation continued to progress until diagnosis. CONCLUSION: This large-scale study revealed that the temporal progression of focal parenchymal atrophy is the earliest detectable sign indicating pancreatic ductal adenocarcinoma. These results provide crucial insights for early pancreatic ductal adenocarcinoma detection.

Integrated analysis of tertiary lymphoid structures in relation to tumor-infiltrating lymphocytes and patient survival in pancreatic ductal adenocarcinoma.

BACKGROUND: Tertiary lymphoid structure (TLS) reflects an intense immune response against cancer, which correlates with favorable patient survival. However, the association of TLS with tumor-infiltrating lymphocytes (TILs) and clinical outcomes has not been investigated comprehensively in pancreatic ductal adenocarcinoma (PDAC). METHODS: We utilized an integrative molecular pathological epidemiology database on 162 cases with resected PDAC, and examined TLS in relation to levels of TILs, patient survival, and treatment response. In whole-section slides, we assessed the formation of TLS and conducted immunohistochemistry for tumor-infiltrating T cells (CD4, CD8, CD45RO, and FOXP3). As confounding factors, we assessed alterations of four main driver genes (KRAS, TP53, CDKN2A [p16], and SMAD4) using next-generation sequencing and immunohistochemistry, and tumor CD274 (PD-L1) expression assessed by immunohistochemistry. RESULTS: TLSs were found in 112 patients with PDAC (69.1%). TLS was associated with high levels of CD4+ TILs (multivariable odds ratio [OR], 3.50; 95% confidence interval [CI] 1.65-7.80; P = 0.0002), CD8+ TILs (multivariable OR, 11.0; 95% CI 4.57-29.7, P < 0.0001) and CD45RO+ TILs (multivariable OR, 2.65; 95% CI 1.25-5.80, P = 0.01), but not with levels of FOXP3+ TILs. TLS was associated with longer pancreatic cancer-specific survival (multivariable hazard ratio, 0.37; 95% CI 0.25-0.56, P < 0.0001) and favorable outcomes of adjuvant S-1-treatment. TLS was not associated with driver gene alterations but tumor CD274 negative expression. CONCLUSIONS: Our comprehensive data supports the surrogacy of TLS for vigorous anti-tumor immune response characterized by high levels of helper and cytotoxic T cells and their prognostic role.

Prospective multicenter evaluation of moving cell metallic stents in endoscopic multiple stent deployment for hepatic hilar obstruction.

BACKGROUND AND AIM: Bilateral stent deployment for malignant biliary obstruction (MHBO) can be achieved using side-by-side (SBS) or stent-in-stent (SIS) procedures. Compared with SBS techniques, the procedural steps of SIS are technically complex due to the necessity of introducing the delivery system into a contralateral biliary tract through the mesh of the SEMS. To overcome this issue, a novel uncovered SEMS, the HILZO Moving Cell Stent (MCS) has been released. The present study examined the technical feasibility of treating MHBO using bilateral deployment of this novel stent without dilating the mesh of the first stent to achieve insertion of the second stent within a single session, using a prospective, multicenter setting. METHOD: The primary outcome in the present study was the technical success rate. Technical success was defined as deployment of bilateral MCSs into two or more biliary tracts using SIS without a dilation device in a single-session. RESULTS: A total of 27 patients with complications of MHBO were enrolled in this study. Bilateral SIS using two MCS was successfully performed in 23 patients without using dilation devices among 27 patients (initial technical success rate; 85.2%). Median time to recurrent biliary obstruction (TRBO) was 271 days. Stent dysfunction was observed in 12 patients (44.4%), and re-intervention was successfully performed in all patients without one patient who instead received best supportive care. CONCLUSIONS: The SIS technique using MCS without dilation of the mesh may be technically feasible and safe. In addition, this may be useful for re-intervention. Further comparative randomized trials are needed.

Possibility of detecting intraductal papillary mucinous neoplasms using metabolite biomarkers for pancreatic cancer.

Aim: The aim of this study was to identify whether metabolite biomarker candidates for pancreatic cancer (PC) could aid detection of intraductal papillary mucinous neoplasms (IPMN), recognized as high-risk factors for PC. Materials & methods: The 12 metabolite biomarker candidates, which were found to be useful to detect PC in our previous study, were evaluated for plasma samples from patients with PC (n = 44) or IPMN (n = 24) or healthy volunteers (n = 46). Results: Regarding the performance of individual biomarkers of PC and PC high-risk IPMN, lysine exhibited the best performance (sensitivity: 67.8%; specificity: 86.9%). The multiple logistic regression analysis-based detection model displayed high sensitivity and specificity values of 92.5 and 90.6%, respectively. Conclusion: Metabolite biomarker candidates for PC are useful for detecting high-risk IPMN, which can progress to PC.

Endoscopic Self-Expandable Metal Stent Placement for Malignant Afferent Loop Obstruction After Pancreaticoduodenectomy: A Case Series and Review.

In this study, we assessed a series of our cases in which endoscopic self-expandable metal stents (SEMSs) were used to treat malignant afferent loop obstruction (ALO) that arose after pancreaticoduodenectomy (PD). We retrospectively examined the records of 7 patients who underwent endoscopic SEMS placement for malignant ALO following PD. Clinical success was achieved in all cases. The median procedure time was 30 min (range, 15-50 min). There were no cases of stent occlusion, and no procedure-related adverse events were encountered. All patients died of their primary disease, and the median overall survival period was 155 days (range, 96-374 days). A re-intervention involving endoscopic ultrasound-guided hepaticogastrostomy combined with antegrade stenting was performed for obstructive jaundice and acute cholangitis in 1 case. In conclusion, endoscopic SEMS placement may be an effective and safe treatment for malignant ALO that arises after PD.

A Case in which an Intraductal Papillary Neoplasm of the Bile Duct Was Surgically Resected 12 Years after the Initial Diagnosis.

A 66-year-old Japanese man was referred to our hospital with multiple giant liver cysts. The cysts had already been detected as multiple 3-cm cysts with small nodules at another hospital 12 years prior to this presentation. The cysts were diagnosed as an intraductal papillary neoplasms of the bile duct (IPNB) occupying the right lobe of the liver. Extended right lobectomy was performed. Based on the pathological findings, the tumor was diagnosed to be an oncocytic-type IPNB with minimal invasion. This experience suggests that the progression of IPNBs occur relatively slowly. The present case might provide important information for understanding the natural history of IPNBs.

Prediction of pancreatic atrophy after steroid therapy using equilibrium-phase contrast computed tomography imaging in autoimmune pancreatitis.

BACKGROUND AND AIMS: Imaging tools for predicting pancreatic atrophy after steroid therapy in autoimmune pancreatitis (AIP) have not been established. As delayed equilibrium-phase contrast enhancement in computed tomography (CE-CT) may reflect interstitial fibrosis, we evaluated the ability of equilibrium-phase CT imaging for predicting pancreatic atrophy. METHODS: Forty-six steroid-treated AIP patients who underwent contrast-enhanced CT at our university hospital were included in this retrospective study. CT attenuation (Hounsfield units [HU]) values in noncontrast images (NC) and equilibrium-phase images (EP) and the differences in HU values between NC and EP images (SUB) were measured. Pancreatic volume was measured in CE-CT before (Volpre) and after (Volpost) steroid therapy. The volume reduction rate was calculated. The relationships of CT values with pancreatic atrophy, Volpost, volume reduction rate, and diabetes exacerbation were investigated. RESULTS: CT values in the EP and SUB images before steroid therapy were associated with pancreatic atrophy after steroid therapy (atrophy vs nonatrophy 114.5 ± 12.8 vs 99.5 ± 11.1, P = 0.0002; 70.9 ± 14.72 vs 57.2 ± 13.1, P = 0.003, respectively), but CT values in NC images were not (P = 0.42). CT values in EP and SUB images before steroid therapy were correlated with Volpost (EP images r = -0.70, P = 0.002; SUB images r = -0.68, P = 0.03) and volume reduction rate after steroid therapy (EP images: r = -0.55, P < 0.0001; SUB images r = -0.45, P = 0.002). Diabetes exacerbation was associated with higher EP and SUB values (P = 0.009 and P = 0.04, respectively). CONCLUSION: Equilibrium-phase contrast CT imaging may facilitate prediction of pancreatic atrophy after steroid therapy in AIP.

A case of high-grade pancreatic intraepithelial neoplasia diagnosed based on focal pancreatic parenchymal atrophy after acute pancreatitis.

A 60-year-old male visited a previous hospital with upper abdominal pain. He was diagnosed with localized mild acute pancreatitis. Three months later, abdominal contrast-enhanced computed tomography showed focal parenchymal atrophy of the pancreas with distal pancreatic duct dilation. No obvious solid mass could be found at the site of the pancreatic duct stenosis on imaging examinations. Endoscopic retrograde pancreatography showed focal mild stenosis with distal pancreatic duct dilation in the tail of the pancreas. Carcinoma in situ of the pancreas was strongly suspected, especially based on the presence of focal atrophy of the pancreas around the site of stenosis of the main pancreatic duct and the distal pancreatic duct dilation. Laparoscopic distal pancreatectomy was performed. Histologically, high-grade pancreatic intraepithelial neoplasia was found in the epithelium of the stenotic main pancreatic duct and its branches. This case suggests that localized acute pancreatitis and focal atrophy of the pancreas with distal dilation of the pancreatic duct could be important clinical manifestations of pancreatic carcinoma in situ.