A case of intracystic papillary neoplasm of the gallbladder that exhibited findings similar to gallbladder adenomyomatosis with the formation of intramural cysts because of Rokitansky-Aschoff sinus infiltration.

A 74-year-old man underwent regular follow-up observations after being diagnosed with gallbladder adenomyomatosis based on findings, such as the thickening of the wall of the gallbladder fundus and the presence of intramural cysts. Over the course of 3 years, a papillary tumor located on the thickened wall of the gallbladder had increased in size and extended into the lumen. Consequently, the patient was diagnosed with gallbladder cancer and underwent extended cholecystectomy. The histological diagnosis was intracystic papillary neoplasm (ICPN) of the gallbladder. Although several Rokitansky-Aschoff sinuses that had increased in size because of tumor progression were observed, no adenomyomatosis of the gallbladder was detected. ICPN, a recently identified disease, is not widely known to present with imaging findings similar to adenomyomatosis. The primary treatment of ICPN is radical resection, whereas adenomyomatosis is generally conservatively managed with regular follow-up observations. As the treatment strategies for these two diseases greatly differ, differential diagnosis must be carefully performed.

The zinc transporter LIV-1 is a novel regulator of stemness in pancreatic cancer cells.

OBJECTIVE: Recent studies have identified the existence a portion of cancer cells, called "cancer stem cells", within the entire cancer tissue. Cancer stem cells harbor highly tumorigenic and chemo-resistant phenotypes, which lead to recurrence or re-growth of the tumor after surgery. The mechanisms that regulate the stemness of cancer cells remain largely unknown. We hypothesized that LIV-1, a zinc transporter, regulates the stemness in pancreatic cancer cells. MATERIAL AND METHODS: We established two stable Panc-1 pancreatic cancer cell lines in which LIV-1 expression was knocked down by the introduction of siRNA against LIV-1. Expression of cancer stem cell-related molecules was examined by quantitative real-time PCR. Expression of ATP-binding cassette sub-family G member 2 was also determined by flow cytometry. Spheroid culture was performed in low-adhesion coated plates. Cell migration was determined by using a modified 2-chamber migration assay. In vivo tumor formation was assessed in nude mice after the subcutaneous injection of cancer cells. The Agilent's miRNA microarray was used to identify differentially expressed miRNAs. RESULTS: Knockdown of LIV-1 expression resulted in (i) decreased expression of cancer stem cell-related molecules such as LIN28 and ATP-binding cassette sub-family G member 2, (ii) decreased spheroid-forming ability, (iii) decreased migration, (iv) decreased incidence of tumor formation in nude mice, and (v) upregulation of miR-7 expression. CONCLUSIONS: Our results suggest that LIV-1 might act as a novel regulator of stemness in pancreatic cancer cells.

The usefulness of endoscopic ultrasound-guided fine-needle aspiration for the diagnosis of pancreatic neuroendocrine tumors based on the World Health Organization classification.

BACKGROUND: We assessed the controversial topic of using 22-gauge needles in endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) for the diagnosis and evaluation of Ki67 labeling indices (Ki67LI) of pancreatic neuroendocrine tumors (pNET). METHODS: Thirty-eight patients with pNET who underwent EUS-FNA between January 1, 2008 and December 31, 2012 were enrolled in this study. When available, the Ki67LI and WHO classifications obtained by EUS-FNA and surgical resection were compared. RESULTS: EUS-FNA with a 22-gauge needle acquired sufficient histological sample to correctly diagnose pNET in 35 cases (92.1%). Both EUS-FNA and surgical histological specimens were available for 19 cases, and grading classes of the 2 procedures were consistent in 17 cases (89.5%) according to the WHO classification based on the Ki67LI. Tumor size was associated with a difference in the Ki67LI between the 2 procedures, although the Ki67LI was almost completely consistent for tumors less than 18 mm in size. CONCLUSIONS: EUS-FNA with a 22-gauge needle is a safe and highly accurate technique for the diagnosis of pNET. There was a clear correlation between the Ki67LI of histological specimens acquired by EUS-FNA and surgery. EUS-FNA with a 22-gauge needle is useful to predict the WHO classification of pNET.

miR-197 induces epithelial-mesenchymal transition in pancreatic cancer cells by targeting p120 catenin.

Invasive ductal adenocarcinoma (IDA) of the pancreas manifests poor prognosis due to the early invasion and distant metastasis. In contrast, intraductal papillary mucinous adenoma or carcinoma (IPMA or IPMC) reveals better clinical outcomes. Various molecular mechanisms contribute to these differences but entire picture is still unclear. Recent researches emphasized the important role of miRNA in biological processes including cancer invasion and metastasis. We previously described that miR-126 is down-regulated in IDA compared with IPMA or IPMC, and miR-126 regulates the expression of invasion related molecule disintegrin and metalloproteinase domain-containing protein 9 (ADAM9). Assessing the difference of miRNA expression profiles of IDA, IPMA, and IPMC, we newly identified miR-197 as an up-regulated miRNA specifically in IDA. Expression of miR-197 in pancreatic cancer cells resulted in the induction of epithelial-mesenchymal transition (EMT) along with the down-regulation of p120 catenin which is a putative target of miR-197. Direct interaction between miR-197 and p120 catenin mRNA sequence was confirmed by 3'UTR assay, and knockdown of p120 catenin recapitulated EMT induction in pancreatic cancer cells. In situ hybridization of miR-197 and immunohistochemistry of p120 catenin showed mutually exclusive patterns suggesting pivotal role of miR-197 in the regulation of p120 catenin. This miR-197/p120 catenin axis could be a novel therapeutic target.

Diagnosis of autoimmune pancreatitis by EUS-FNA by using a 22-gauge needle based on the International Consensus Diagnostic Criteria.

BACKGROUND: It is controversial whether EUS-guided FNA by using 22-gauge (G) needles is useful for the diagnosis or evaluation of autoimmune pancreatitis (AIP). OBJECTIVE: To evaluate the usefulness of EUS-FNA by 22-G needles for the histopathological diagnosis of AIP. DESIGN: A retrospective study. SETTING: Single academic center. PATIENTS: A total of 273 patients, including 25 with AIP, underwent EUS-FNA and histological examinations. RESULTS: EUS-FNA by using 22-G needles provided adequate tissue samples for histopathological evaluation because more than 10 high-power fields were available for evaluation in 20 of 25 patients (80%). The mean immunoglobulin G4-positive plasma cell count was 13.7/high-power field. Obliterative phlebitis was observed in 10 of 25 patients (40%). In the context of the International Consensus Diagnostic Criteria for AIP, 14 and 6 of 25 patients were judged to have level 1 (positive for 3 or 4 items) and level 2 (positive for 2 items) histological findings, respectively, meaning that 20 of 25 patients were suggested to have lymphoplasmacytic sclerosing pancreatitis based on the International Consensus Diagnostic Criteria. The diagnosis in 1 patient was type 2 AIP because a granulocytic epithelial lesion was identified in this patient. LIMITATIONS: A retrospective study with a small number of patients. CONCLUSIONS: The results of this study suggest that EUS-FNA by using 22-G needles provides tissue samples adequate for histopathological evaluation and greatly contributes to the histological diagnosis of AIP.

Distinct clinical features of two patients that progressed from the early phase of chronic pancreatitis to the advanced phase.

Chronic pancreatitis (CP) has been considered an intractable inflammatory disease that is progressive and irreversible after definite structural changes appear in the pancreas. The Japanese diagnostic criteria for CP were revised in 2009. One of the reasons for this revision was to define a diagnostic criterion for the early phase of CP (early CP) to improve a patient's clinical outcome, because the disease progression might be reversed in this phase by a therapeutic intervention. However, the clinical features and outcome of early CP remain largely unknown, and the diagnostic reliability of early CP needs to be verified. Here, we show two patients who met the diagnostic criteria of early CP and then progressed to the advanced, late phase of CP (definite CP). A 64-year-old man with recurrent acute pancreatitis was diagnosed as early CP and later progressed to definite CP with multiple pancreatic calcifications at the age of 69. The etiology of CP in this patient was thought to be idiopathic. The other patient was a 57-year-old man with alcohol abuse (ethanol consumption>120 g/day). He was diagnosed as early CP and then rapidly progressed to definite CP without any acute attack. He could not remain abstinent after the diagnosis of early CP. In the present report, we retrospectively demonstrated distinct clinical features of the two patients, both of whom were diagnosed as early CP first and then progressed to definite CP. Thus, our findings support the disease concept of early CP and also suggest the validity of the revised Japanese criteria for the diagnosis of early CP.

Pancreatic duct drainage using EUS-guided rendezvous technique for stenotic pancreaticojejunostomy.

The patient was a 30-year-old female who had undergone excision of the extrahepatic bile duct and Roux-en-Y hepaticojejunostomy for congenital biliary dilatation at the age of 7. Thereafter, she suffered from recurrent acute pancreatitis due to pancreaticobiliary maljunction and received subtotal stomach-preserving pancreaticoduodenectomy. She developed a pancreatic fistula and an intra-abdominal abscess after the operation. These complications were improved by percutaneous abscess drainage and antibiotic therapy. However, upper abdominal discomfort and the elevation of serum pancreatic enzymes persisted due to stenosis from the pancreaticojejunostomy. Because we could not accomplish dilation of the stenosis by endoscopic retrograde cholangiopancreatography, we tried an endoscopic ultrasonography (EUS) guided rendezvous technique for pancreatic duct drainage. After transgastric puncture of the pancreatic duct using an EUS-fine needle aspiration needle, the guidewire was inserted into the pancreatic duct and finally reached to the jejunum through the stenotic anastomosis. We changed the echoendoscope to an oblique-viewing endoscope, then grasped the guidewire and withdrew it through the scope. The stenosis of the pancreaticojejunostomy was dilated up to 4 mm, and a pancreatic stent was put in place. Though the pancreatic stent was removed after three months, the patient remained symptom-free. Pancreatic duct drainage using an EUS-guided rendezvous technique was useful for the treatment of a stenotic pancreaticojejunostomy after pancreaticoduodenectomy.

MiR-126 acts as a tumor suppressor in pancreatic cancer cells via the regulation of ADAM9.

The epithelial-mesenchymal transition (EMT) is a critical step for pancreatic cancer cells as an entry of metastatic disease. Wide variety of cytokines and signaling pathways are involved in this complex process while the entire picture is still cryptic. Recently, miRNA was found to regulate cellular function including EMT by targeting multiple mRNAs. We conducted comprehensive analysis of miRNA expression profiles in invasive ductal adenocarcinoma (IDA), intraductal papillary mucinous adenoma, intraductal papillary mucinous carcinoma, and human pancreatic cancer cell line to elucidate essential miRNAs which regulate invasive growth of pancreatic cancer cells. Along with higher expression of miR-21 which has been shown to be highly expressed in IDA, reduced expression of miR-126 in IDA and pancreatic cancer cell line was detected. The miR-126 was found to target ADAM9 (disintegrin and metalloproteinase domain-containing protein 9) which is highly expressed in pancreatic cancer. The direct interaction between miR-126 and ADAM9 mRNA was confirmed by 3' untranslated region assay. Reexpression of miR-126 and siRNA-based knockdown of ADAM9 in pancreatic cancer cells resulted in reduced cellular migration, invasion, and induction of epithelial marker E-cadherin. We showed for the first time that the miR-126/ADAM9 axis plays essential role in the inhibition of invasive growth of pancreatic cancer cells.

Early detection of low enhanced pancreatic parenchyma by contrast-enhanced computed tomography predicts poor prognosis of patients with acute pancreatitis.

OBJECTIVES: The usefulness of early severity assessment of acute pancreatitis (AP) by contrast-enhanced computed tomography (CECT) was investigated. METHODS: Data were obtained from a 2007 nationwide survey in Japan. Clinical data of 983 patients with AP were analyzed. All were examined by CECT on the day of admission. RESULTS: Early findings of CECT demonstrated that low enhanced pancreatic parenchyma (LEPP) was associated with the incidence of organ failure (OF), multiple OF, and infectious complications as well as mortality (P < 0.0001). Next, patients were further divided into 4 groups according to the CECT findings, which focused on the LEPP and peripancreatic collections (PPCs). The LEPP/PPC (+/+) group was characterized as high morbidity and high mortality. The incidence of OF (28.2%), multiple OF (15.5%), and mortality (11.4%) in patients assigned to the (+/+) group was significantly higher than in those assigned to the other groups. The incidence of infectious complications was significantly higher in patients assigned to the (+/+) group (16.7%), the (+/-) group (9.0%), and the (-/+) group (7.0%) than those assigned to the (-/-) group (1.8%). CONCLUSIONS: The detection of LEPP and PPC was a useful CECT finding for the early assessment of the severity of AP.

The evaluation of MSX2 mRNA expression level in biliary brush cytological specimens.

BACKGROUND: To distinguish cholangiocarcinoma from inflammatory disease remains difficult when stricture is present in the bile duct. Endoscopic brushing cytology is a convenient method for stricture in the bile duct, however, the diagnostic sensitivity of this method for malignancy is reported to be low (<60%). Msh homeobox 2 is frequently expressed in carcinoma cells of epithelial origin but not in normal tissues. AIM: To assess whether MSX2 expression level in brushing samples allows differentiation of malignant from benign bile duct stricture. PATIENTS AND METHODS: Cytological brushing specimens were obtained from strictures of the bile duct during endoscopic retrograde cholangiopancreaticography (ERCP) in 71 patients. The brushing fluid was subjected to cytological diagnosis and RNA extraction. The expression level of MSX2 was evaluated by one-step real-time RT-PCR. RESULTS: MSX2 expression levels were significantly higher in malignant than in benign bile duct stricture (p=0.004). The sensitivity and specificity for cholangiocarcinoma of cytology and MSX2 expression in strictures of the bile duct were: 55.3% and 100%, and 72.3% and 58.3%, respectively. CONCLUSION: The sensitivity of MSX2 expression level for cholangiocarcinoma was much higher than that of cytology. This suggests that the evaluation of MSX2 level in ERCP brushing samples would be a useful tool to distinguish malignant from benign bile duct stricture.

Long-period pancreatic stenting for painful chronic calcified pancreatitis required higher medical costs and frequent hospitalizations compared with surgery.

OBJECTIVES: The aim of this study was to compare the benefits between endoscopic drainage and surgical drainage of the pancreatic duct for patients with chronic calcified pancreatitis. METHODS: A total of 68 patients were classified into endoscopic (n = 34) or surgical (n = 34) treatment groups. Patients receiving endoscopic treatment were further divided into 2 subgroups: a short-period group, patients who could discontinue serial pancreatic stenting within 1 year (n = 19); and a long-period group, patients who needed pancreatic drainage by serial endoscopic stenting for more than 1 year (n = 15). The medical records of these patients were retrospectively analyzed. RESULTS: Hospital stays, frequency of hospitalizations, and medical expense were similar between the short-period endoscopic treatment group and surgery group. On the other hand, patients in the long-period endoscopic treatment group required significantly longer hospital stays, more frequent hospitalizations, and had higher medical expenses than the short-period endoscopic treatment group as well as than the surgery group. CONCLUSIONS: Patients who underwent serial endoscopic stenting for more than 1 year showed no benefit compared with surgical treatment in terms of the frequency of hospital stays and medical costs.

Perfusion computed tomography findings of autoimmune pancreatitis.

OBJECTIVES: The aim of this study was to clarify the pancreatic blood perfusion in patients with autoimmune pancreatitis (AIP) and the changes after steroid treatment. METHODS: Perfusion computed tomography was performed in 11 patients with AIP and 12 control subjects. Pancreatic volumetric blood flow (F(V)), volume of distribution (V(D)), and blood transit time τ were determined from a single-compartment kinetic model. Nine patients with AIP were reexamined by perfusion computed tomography after corticosteroid administration. RESULTS: The pancreatic F(V) values of the 11 patients with AIP (82.7/min) were significantly lower than those of control subjects (163.5/min, P = 0.0006). On the other hand, the pancreatic V(D) and τ values were not significantly different between AIP and normal. After steroid treatment, the F(V) values of 9 reexamined patients with AIP (76.2/min) were significantly elevated (109.8/min, P = 0.0391). However, the changes of the values after the treatment differed in degree among individuals. The values of 4 patients were dramatically elevated to greater than 100/min, whereas those of 4 other patients did not improve well. The value of the remaining patient whose initial F(V) value was normal (168.09/min) did not change after the treatment. CONCLUSIONS: Pancreatic volumetric perfusion was attenuated in AIP patients. The perfusion was improved after the steroid treatment.

LIV-1 enhances the aggressive phenotype through the induction of epithelial to mesenchymal transition in human pancreatic carcinoma cells.

LIV-1 is a downstream target of STAT3 and is essential for the nuclear localization of Snail, a master regulator of epithelial to mesenchymal transition (EMT). Little is known about the association of LIV-1 with pancreatic carcinoma development, therefore, expression of LIV-1 mRNA was analyzed by real-time reverse transcriptase polymerase chain reaction (RT-PCR) in 9 cultured cell lines (8 carcinoma and 1 normal duct cell lines) and 24 pancreatic tissues (12 carcinoma and 12 normal tissues). Localization of this gene product was investigated by immunohistochemistry in 72 pancreatic carcinoma and the relation between its expression and clinicopathological findings was examined. To assess the function of LIV-1 in pancreatic carcinoma cells, stable siRNA expressing Panc-1 cells were generated. Higher expression of LIV-1 mRNA was found in both pancreatic carcinoma cell lines and pancreatic carcinoma tissues compared to normal duct cell line and histologically normal tissues, respectively. Immunohistochemical analysis revealed that LIV-1 expression was frequently found in 76.4% of pancreatic carcinoma tissues and its expression level was associated with tumor size and lymphatic infiltration. Down-regulated LIV-1 cells showed significant inhibition of anchorage-dependent or -independent proliferation and cell motility in vitro and reduction of tumor growth and metastasis in vivo. Furthermore, nuclear expression of Snail was decreased and E-cadherin expression was restored in LIV-1 siRNA expressing pancreatic carcinoma cells. These findings indicate that LIV-1 may be involved in acquisition of the aggressive phenotype of human pancreatic carcinoma cells through the induction of epithelial to mesenchymal transition.