Concordance of the histological diagnosis of type 1 autoimmune pancreatitis and its distinction from pancreatic ductal adenocarcinoma with endoscopic ultrasound-guided fine needle biopsy specimens: an interobserver agreement study.

The histological diagnosis of type 1 autoimmune pancreatitis (AIP) based on the findings obtained by an endoscopic ultrasound-guided fine needle biopsy (EUS-FNB) is feasible, but the diagnostic consistency of this method has not been confirmed. We determined the interobserver agreement among 20 pathologists regarding the diagnosis of type 1 AIP, including the distinction from pancreatic ductal adenocarcinoma (PDAC) using large tissue samples obtained by EUS-FNB. After guidance for diagnosing AIP with biopsy tissues was provided, a round 2 was performed. The median sensitivity and specificity for diagnosing PDAC vs. non-neoplastic diseases were 95.2% and 100%, respectively. In groups of specialists (n = 7) and the generalists (n = 13), Fleiss' к-values increased from 0.886 to 0.958 and from 0.750 to 0.816 in round 2. The concordance was fair or moderate for obliterative phlebitis and storiform fibrosis but slight for ductal lesion of type 1 AIP. Discordant results were due to ambiguous findings and biopsy tissue limitations. Among the specialists, the ratio of cases with perfect agreement regarding the presence of storiform fibrosis increased in round 2, but agreement regarding obliterative phlebitis or ductal lesions was not improved. Although the histological definite diagnosis of type 1 AIP was achieved by most observers in > 60% of the cases, the confidence levels varied. Because some ambiguities exist, the histological diagnostic levels based on the diagnostic criteria of type 1 AIP should not be taken for granted. Guidance is effective for improving accurate PDAC diagnoses (notably by recognizing acinar-ductal metaplasia) and for evaluating storiform fibrosis.

Daily Coffee Intake Inhibits Pancreatic Beta Cell Damage and Nonalcoholic Steatohepatitis in a Mouse Model of Spontaneous Metabolic Syndrome, Tsumura-Suzuki Obese Diabetic Mice.

BACKGROUND: Metabolic syndrome is one of the most important health issues worldwide. Obesity causes insulin resistance, hyperlipidemia, diabetes, and various diseases throughout the body. The liver phenotype, which is called nonalcoholic steatohepatitis (NASH), frequently progresses to hepatocellular carcinoma. We recently established a new animal model, Tsumura-Suzuki obese diabetic (TSOD) mice, which spontaneously exhibit obesity, diabetes, hyperlipidemia, and NASH with liver nodules. METHODS: We examined the effects of coffee intake on various conditions of the metabolic syndrome using TSOD mice. The daily volume of coffee administered was limited so that it reflected the appropriate quantities consumed in humans. To clarify the effects of the specific components, animals were divided into two coffee-intake groups that included with and without caffeine. RESULTS: Coffee intake did not significantly affect obesity and hyperlipidemia in TSOD mice. In contrast, coffee intake caused various degrees of improvement in the pancreatic beta cell damage and steatohepatitis with liver carcinogenesis. Most of the effects were believed to be caused by a synergistic effect of caffeine with other components such as polyphenols. However, the antifibrotic effects of coffee appeared to be due to the polyphenols rather than the caffeine. CONCLUSIONS: A daily habit of drinking coffee could possibly play a role in the prevention of metabolic syndrome.

Histopathological characteristics of glutamine synthetase-positive hepatic tumor lesions in a mouse model of spontaneous metabolic syndrome (TSOD mouse).

We previously reported that Tsumura-Suzuki obese diabetic (TSOD) mice, a polygenic model of spontaneous type 2 diabetes, is a valuable model of hepatic carcinogenesis via non-alcoholic fatty liver disease (NAFLD) and non-alcoholic steatohepatitis (NASH). One of the characteristics of tumors in these mice is the diffuse expression of glutamine synthetase (GS), which is a diagnostic marker for hepatocellular carcinoma (HCC). In this study, we performed detailed histopathological examinations and found that GS expression was diffusely positive in >70% of the hepatic tumors from 15-month-old male TSOD mice. Translocation of ß-catenin into nuclei with enhanced membranous expression also occurred in GS-positive tumors. Small lesions (<1 mm) in GS-positive cases exhibited dysplastic nodules, with severe nuclear atypia, whereas large lesions (>3 mm) bore the characteristics of human HCC, exhibiting nuclear and structural atypia with invasive growth. By contrast, the majority of GS-negative tumors were hepatocellular adenomas with advanced fatty change and low nuclear grade. In GS-negative tumors, loss of liver fatty acid-binding protein expression was observed. These results suggest that the histological characteristics of GS-positive hepatic tumors in TSOD mice resemble human HCC; thus, this model may be a useful tool in translational research targeting the NAFLD/NASH-HCC sequence.

Extranodal NK/T-cell lymphoma, nasal type, manifesting as rapidly progressive dementia without any mass or enhancing brain lesion.

Among the many potential etiologies for rapidly progressive dementia (RPD), primary central nervous system extranodal NK/T-cell lymphoma, nasal-type (ENKL) is a rare entity. We present the first reported case of autopsy-proven RPD due to ENKL without any mass or enhancing lesion of the brain. A 54-year-old immunocompetent man presented with RPD, myoclonus and ataxia. The mini-mental state examination (MMSE) score was 22/30. His brain MRI revealed progressive brain atrophy without gadolinium enhancement or mass lesion. Five months after the initial evaluation, cognitive impairment further worsened with an MMSE score of 3/30. At the advanced stage, lumbar MRI showed swollen cauda equina with gadolinium enhancement. The number of Epstein-Barr virus (EBV) DNA in cerebrospinal fluid had gradually increased. Twelve months after onset, the patient died of respiratory failure. Pathological findings revealed that lymphoma cells had diffusely invaded the meninges, parenchyma of the brain, spinal cord and cauda equina. Cells were positive for CD3, CD56 and EBV-encoded small RNAs and negative for CD20. No evidence of malignancy was identified in the visceral organs. This report indicates that ENKL should be recognized as one of the rare causes of RPD. Early testing for EBV-DNA in cerebrospinal fluid and imaging of cauda equina would be useful diagnostic tools.