The major indication for steroid treatment in AIP is the presence of symptoms. An initial prednisolone dose of 0.6 mg/kg/day, is recommend, which is then reduced to a maintenance dose over a period of 3-6 months. Maintenance treatment with low-dose steroid reduces but dose not eliminate relapses.

The role of long noncoding RNAs (lncRNAs) in the epithelial‐mesenchymal transition (EMT) in pancreatic ductal adenocarcinoma (PDAC) is unclear. Some lncRNAs can be transferred by extracellular vesicles (EVs) and have potential as biomarkers. Here, we identify an lncRNA that could serve as a biomarker for PDAC and show the functional roles of the lncRNA. Expression profiling of lncRNAs revealed that highly upregulated in liver cancer (HULC) was highly expressed, and induced, by transforming growth factor‐β in PDAC cells and their EVs. Knockdown of HULC decreased PDAC cell invasion and migration by inhibiting the EMT. Thus, HULC could be transferred by EVs, and promote EMT, invasion, and migration in recipient PDAC cells. To assess the roles of HULC, PDAC cell xenografts in nude mice were established. Knockdown of HULC in PDAC cells implanted in mice inhibited tumor growth. Moreover, microRNA‐133b suppressed PDAC cell invasion and migration by inhibiting the EMT through targeting HULC. Furthermore, serum samples were obtained from 20 PDAC and 22 intraductal papillary mucinous neoplasm (IPMN) patients, as well as 21 healthy individuals. Analysis of serum EV HULC expression by digital PCR showed that HULC expression was significantly increased in PDAC patients compared to healthy individuals or IPMN patients. Additionally, HULC showed good predictive performance for discriminating PDAC, suggesting that the analysis of EV‐encapsulated HULC would contribute to the diagnosis for human PDAC. Extracellular vesicle‐transported HULC promotes cell invasion and migration by inducing the EMT, and microRNA‐133b suppresses the EMT by targeting HULC. Extracellular vesicle‐encapsulated HULC could be a potential circulating biomarker for human PDAC.

Pancreatic hamartoma is a rare tumor, and its characteristic histopathologic features have not yet been fully evaluated. In this study, we collected 9 cases of pancreatic hamartoma to elucidate distinctive histopathologic features that can serve to establish this tumor as a clear disease entity and thus formulate useful histopathologic criteria for this tumor. The cases comprised 4 men and 5 women with a mean age of 62.7 years. The average tumor diameter was 3.3 cm. All patients underwent surgical treatment, and none showed any recurrence postoperatively. Macroscopically, pancreatic hamartomas were well-demarcated tumors with a solid or solid and cystic appearance. Microscopically, these tumors comprised mature acini and small-sized to medium-sized ducts showing a distorted architecture with various amounts of fibrous stroma. Strikingly, the tumors consistently lacked concentric elastic fibers in their duct walls, peripheral nerves, and well-formed islets of Langerhans, all of which exist in both the normal and atrophic pancreas. Immunohistochemically, scattered chromogranin A-positive neuroendocrine cells were observed in the acinar and ductal components. Ductal components were positive for S-100 protein. Spindle-shaped stromal cells expressed CD34 and/or c-kit. These histopathologic features were distinct from those of 5 cases of pancreatic ductal adenocarcinoma, 3 cases of type 1 autoimmune pancreatitis (lymphoplasmacytic sclerosing pancreatitis), 3 cases of alcoholic chronic pancreatitis, and 5 cases of normal pancreas. In conclusion, pancreatic hamartomas share some distinctive histopathologic features and clinical outcomes (neither recurrence nor metastasis) that allow them to be interpreted as malformative lesions. The term "hamartoma" is appropriate for these unique lesions.

Neoadjuvant chemotherapy/neoadjuvant chemoradiotherapy (NAC/NACRT) can be performed in patients with pancreatic cancer to improve survival. We aimed to clarify the clinical outcomes of biliary drainage with a metal stent (MS) or a plastic stent (PS) during NAC/NACRT. Between October 2013 and April 2016, 96 patients with pancreatic cancer were registered for NAC/NACRT. Of these, 29 patients who underwent biliary drainage with MS or PS before NAC/NACRT and a subsequent pancreatoduodenectomy were retrospectively analyzed with regard to patient characteristics, preoperative recurrent biliary obstruction rate, NAC/NACRT delay or discontinuation rate, and operative characteristics. The median age of the patients was 67 years. NAC and NACRT were performed in 14 and 15 patients, respectively, and MS and PS were used in 17 and 12 patients, respectively. Recurrent biliary obstruction occurred in 6% and 83% of the patients in the MS and PS groups, respectively (p<0.001). NAC/NACRT delay was observed in 35% and 50% of the patients in the MS and PS groups, respectively (p=0.680). NAC/NACRT discontinuation was observed in 12% and 17% of the patients in the MS and PS groups, respectively (p=1.000). The operative time in the MS group tended to be longer than that in the PS group (625 minutes vs 497 minutes, p=0.051), and the operative blood loss volumes and postoperative adverse event rates were not different between the two groups. MS was better than PS from the viewpoint of preventing recurrent biliary obstruction, although MS was similar to PS with regards to perioperative outcomes.

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