Pancreatic cancer is lethal, as it is often detected late. Thus, novel biomarkers of precursor lesions are needed to devise timely therapies. Pancreatic intraepithelial neoplasia (PanIN) and intraductal papillary mucinous neoplasm (IPMN) are major precursors of pancreatic cancer. In normal gastric mucosa, gastric gland mucin‐specific O‐glycans are unique in having α1,4‐linked N‐acetylglucosamine (αGlcNAc) residues attached to MUC6. Recently we reported that αGlcNAc functions as a tumor suppressor for differentiated‐type gastric adenocarcinoma (Karasawa et al., J Clin Invest 122, 923, 2012). MUC6 is also expressed in pancreatic neoplasms, including PanIN and IPMN, but the role of αGlcNAc expression in pancreatic neoplasms remains unknown. Here, we analyze expression patterns of αGlcNAc, MUC6 and MUC5AC in pancreatic neoplasms and compare them with progression from PanIN to invasive ductal adenocarcinoma (IDAC) (the PanIN‐IDAC sequence; 20 cases) and from IPMN to IPMN with associated invasive carcinoma (IPMNAIC) (the IPMN‐IPMNAIC sequence; 20 cases). At both sequences, the frequency of MUC6‐positive and αGlcNAc‐positive lesions decreased with tumor progression. We then compared expression levels of αGlcNAc and MUC6 at each step of the progression. At the PanIN‐IDAC sequence, αGlcNAc expression significantly decreased relative to MUC6 in low‐grade PanIN (P = 0.021), high‐grade PanIN/intraductal spread of IDAC (P = 0.031) and IDAC (P = 0.013). At the IPMN‐IPMNAIC sequence, decreased αGlcNAc expression was also observed in low‐grade IPMN exhibiting gastric‐type morphology (P = 0.020). These results suggest that decreased expression of αGlcNAc relative to MUC6 occurs early and marks the initiation of tumor progression to pancreatic cancer.

Placental mesenchymal dysplasia (PMD) is characterized by multiple hypoechoic vesicles which are similar to molar changes in the placenta; however, the process of such morphological changes of PMD during pregnancy has not been fully understood. We performed a review of all PMD cases published in English and identified 49 articles including 110 cases. With regard to the gestational age at which the multicystic pattern was seen,approximately 70% of cases were diagnosed at 13-20 weeks of gestation. Another characteristic feature of PMD is varicose dilation of fetal chorionic vessels. As many as 90% of cases were diagnosed as placenta with dilated fetal chorionic vessels in the third trimester. We also report a case of PMD which was found at 10 weeks of gestation according to ultrasonic molar patterns. Serial observations of the placenta using ultrasound and magnetic resonance imaging revealed that multicystic lesions became smaller after 23 weeks. In contrast, dilated placental vessels on the fetal side became apparent at 38 weeks. The present review highlights that placental vesicular lesions of PMD may precede dilation of fetal chorionic vessels during pregnancy. It also indicates the potential of a gradual reduction in size of PMD's placental vesicular lesions by serial study of placental images.

Objectives:To compare radial volumetric imaging breath-hold examination with k-space weighted image contrast reconstruction (r-VIBE-KWIC) to Cartesian VIBE (c-VIBE) in arterial phase dynamic gadoxetic acid (Gd-EOB-DTPA)-enhanced magnetic resonance imaging (DCE-MRI) of the liver. Methods:We reviewed 53 consecutive DCE-MRI studies performed on a 3-T unit using c-VIBE and 53 consecutive cases performed using r-VIBE-KWIC with full-frame image subset (r-VIBEfull) and sub-frame image subsets (r-VIBEsub; temporal resolution, 2.5-3 s). All arterial phase images were scored by two readers on: (1) contrast-enhancement ratio (CER) in the abdominal aorta; (2) scan timing; (3) artefacts; and (4) visualisation of the common, right, and left hepatic arteries. Results:Mean abdominal aortic CERs for c-VIBE, r-VIBEfull, and r-VIBEsub were 3.2, 4.3, and 6.5, respectively. There were significant differences between each group (P < 0.0001).The mean score for c-VIBE was significantly lower than that for r-VIBEfull and rVIBEsub in all factors except for visualisation of the common hepatic artery (P < 0.05).The mean score of all factors except for scan timing for r-VIBEsub was not significantly different from that for r-VIBEfull. Conclusion:r-VIBE-KWIC provides higher image quality than c-VIBE, and r-VIBEsub features high temporal resolution without image degradation in arterial phase DCE-MRI. ・Using r-VIBE-KWIC, optimal arterial phase images were obtained in over 90%.・Using r-VIBE-KWIC, visualisation of the hepatic arteries was improved. ・A two-reader study revealed r-VIBE-KWIC's advantages over Cartesian VIBE.Abbreviations VIBE, volumetric imaging breath-hold examination; KWIC, k-space weighted image contrast reconstruction; DCE-MRI, dynamic contrast-enhanced magnetic resonance imaging; CER, contrast-enhancement ratio

Polypoid endometriosis is a rare type of endometriosis. We report a case of polypoid endometriosis of the ovary mimicking ovarian carcinoma with peritoneal dissemination. Computed tomography and magnetic resonance imaging showed a left ovarian endometriotic cyst containing several nodules in the cystic wall that displayed enhancement, and pelvic nodules on the right ovary. A preoperative or intraoperative diagnosis to avoid the unnecessary extended operation is important for such disease. Retrospective magnetic resonance imaging analysis identified a peculiar finding for polypoid endometriosis: all solid nodules had a round and smooth shape and displayed a low-signal-intense marginal edge on T2-weighted images, suggesting that this is an important finding for differentiating polypoid endometriosis from ovarian carcinoma arising from endometriosis.

Objectives: Type 1 autoimmune pancreatitis (AIP) is histologically characterized by dense lymphoplasmacytic infiltration and marked storiform fibrosis, manifestations associated with pancreatic ducts. Such periductal lymphocyte recruitment is thought to be elicited by dysregulation of mechanisms governing physiological lymphocyte homing. The present study was undertaken to determine whether vascular addressins including peripheral lymph node addressin (PNAd) and mucosal addressin cell adhesion molecule 1 (MAdCAM-1) play a role in type 1 AIP histogenesis.Methods: Tissue sections of type 1 AIP and tumor-associated non-AIP chronic pancreatitis, as well as normal pancreas, were subjected to immunohistochemical analysis using vascular addressin-related antibodies.Results: The number of periductal MECA-79 + high endothelial venule (HEV)-like vessels was increased in type 1 AIP relative to that seen in non-AIP chronic pancreatitis, while the number of MAdCAM-1 + HEV-like vessels did not differ between the two conditions. MECA-79 antigens are expressed on duct-forming epithelial cells not only in pancreas but also in salivary glands, which often harbor extrapancreatic lesions in type 1 AIP.Conclusions: Type 1 AIP can be characterized by periductal induction of MECA-79 + HEV-like vessels.MECA-79 + 6-sulfo sialyl Lewis X-related carbohydrate antigens expressed on duct-forming epithelial 3 cells could be associated with type 1 AIP pathogenesis.