Five cases of localized cystic dilatation of a side branch of the main pancreatic duct due to a new entity ("ductectatic" mucinous cystadenoma and cystadenocarcinoma) are reported. The dilated duct was widely covered by epithelium indistinguishable from that of mucinous cystadenoma (n = 4) or cystadenocarcinoma (n = 1) of the pancreas. All lesions were located in the uncinate process and were about 3 cm in size. On computed tomographic scans and sonograms, lesions were difficult to distinguish from simple cyst of the pancreas unless lobulated or irregular margins were demonstrated. Endoscopic retrograde pancreatography (ERP) or operative pancreatography clearly demonstrated characteristic findings: localized, prominent cystic dilatation of a side branch of the main pancreatic duct with grape-like clusters or pear-shaped pools of contrast material associated with filling defects of various sizes. When a cystic lesion is noted in the uncinate process of the pancreas, ERP is mandatory to confirm or rule out this potentially or overtly malignant disease.

Malignant change has not been observed after total or subtotal excision of choledochal cysts in this series.

Background Abnormal miRNA expression was recently implicated in the metastasis of oral squamous cell carcinoma (OSCC) and with a poor prognosis. The initiation of the invasion‐metastasis cascade involves epithelial‐mesenchymal transition (EMT). Our aim was to clarify how miRNA, especially miR‐155‐5p misexpression contributes to OSCC metastasis through EMT. Methods We collected tumor samples from 73 subjects with OSCC. The samples were analyzed by quantitative reverse‐transcription polymerase chain reaction (qRT‐PCR), and correlations between miR‐155‐5p levels and clinical characteristics were investigated. OSCC cell lines were analyzed by miRNA microarray and by transfection with a miR‐155‐5p mimic or inhibitor, followed by proliferation and wound‐healing migration assays. qRT‐PCR analyses of EMT makers in cells transfected with miR‐155‐5p inhibitor were performed. Results We found high miR‐155‐5p expression in tissue samples from subjects with OSCC that had metastasized to cervical lymph nodes. HSC‐3 cells also strongly expressed miR‐155‐5p. The epithelial marker E‐cadherin was strongly expressed in HSC‐3 cells transfected with miR‐155‐5p inhibitor, and we observed elevated SOCS1 and decreased STAT3 expression in these cells. Conclusions Our results suggest that miR‐155‐5p causes OSCC to metastasize, and could serve as a novel therapeutic target for OSCC.

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.

The carboxyl group (COOH) is an omnipresent functional group in organic molecules, and its direct catalytic activation represents an attractive synthetic method. Herein, we describe the first example of a direct catalytic nucleophilic activation of carboxylic acids with BH3·SMe2, after which the acids are able to act as carbon nucleophiles, i.e. enolates, in Mannich-type reactions. This reaction proceeds with a mild organic base (DBU) and exhibits high levels of functional group tolerance. The boron catalyst is highly chemoselective toward the COOH group, even in the presence of other carbonyl moieties, such as amides, esters, or ketones. Furthermore, this catalytic method can be extended to highly enantioselective Mannich-type reactions by using a (R)-3,3'-I2-BINOL-substituted boron catalyst.