Primary Follicular Lymphoma of the Duodenum with Erosions as Atypical Macroscopic Features

A 52-year-old Japanese woman who was eventually diagnosed with primary follicular lymphoma of the duodenum showed atypical endoscopic features, namely, erosions with peripheral whitish edematous mucosa. Initial biopsy specimens taken from the erosions revealed insufficient numbers of lymphoma cells for histological diagnosis. Subsequent biopsy specimens from the peripheral mucosa containing the whitish enlarged villi showed infiltration of the lymphoma cells forming lymphoid follicles, which led us to the appropriate diagnosis. This case indicates that endoscopists should take biopsy samples from the peripheral mucosa with whitish enlarged villi rather than erosions in the rare instances that erosions appear as the main macroscopic feature of intestinal follicular lymphoma

A new basal hadrosaurid (Dinosauria : Ornithischia) from the latest Cretaceous Kita-ama Formation in Japan implies the origin of hadrosaurids

Here we describe a partial hadrosaurid skeleton from the marine Maastrichtian Kita-ama Formation in Japan as a new taxon, Yamatosaurus izanagii gen. et sp. nov., based on unique characters in the dentition. Our phylogenetic analysis demonstrates Yamatosaurus izanagii belongs to Hadrosauridae, composed of Hadrosaurus foulkii + (Yamatosaurus izanagii + (Saurolophinae + Lambeosaurinae)). The coracoid lacks a biceps tubercle as in non-hadrosaurid hadrosauroids, suggesting its presence is a key feature for the clade of Saurolophinae and Lambeosaurinae. The evolutionary rates analysis further supports that shoulder and forelimb features, which are likely to have been involved in locomotion, were important for the early evolution of Hadrosauridae. Our biogeographic analyses show that basal hadrosaurids were widely distributed in Asia and Appalachia, that the clade of Saurolophinae and Lambeosaurinae originated in Asia, and that eastern Asia may have served as a refugium of relict hadrosauroid taxa such as Plesiohadros djadokhtaensis, Tanius sinensis, and Yamatosaurus izanagii during the Late Cretaceous. The contemporaneous occurrence of basal (Yamatosaurus izanagii) and derived (Kamuysaurus japonicus) hadrosaurids during the Maastrichtian in Japan is the first record in Asia. Because of the long geographical distance between these localities, they likely did not co-exist, but instead demonstrate some level of provinciality

Spindle cell carcinoma of the common bile duct

Spindle cell-type undifferentiated carcinoma arising from the extrahepatic bile duct is extremely rare. We report herein a case of this type of carcinoma in the common bile duct of the hepatic hilus. A 59-year-old man was admitted to our hospital complaining of jaundice. Laboratory data revealed elevation of serum CA 19-9. Cholangiography revealed complete obliteration of the left hepatic bile duct and stenosis of the bile duct from the superior to the right hepatic bile duct. Computed tomography showed the tumor, measuring 15×12 mm, in the hepatic hilus, obliteration of the right to main trunk of the portal vein and a lymph node in the hepato-duodenum ligament swelling. Arteriography revealed a kink of the right hepatic artery, so encasement of the right hepatic artery was suspected. We preoperatively diagnosed hilus bile duct carcinoma and scheduled right trisection hepatectomy. Intraoperative frozen sections taken from the tumor and tissues around hepatic arteries showed spindle cells and inflammatory cells, so inflammatory pseudotumor was diagnosed intraoperatively. Because the right hepatic bile duct was occluded, right lobe hepatectomy was performed. However, permanent section revealed both spindle cells and poorly differentiated tubular adenocarcinoma cells positive for CAM5.2, AE1/AE3 and vimentin. Based on these findings, the tumor was finally diagnosed as spindle cell-type undifferentiated carcinoma. The patient died of pulmonary infarction 11 days after the operation

Singar1, a Novel RUN Domain-containing Protein, Suppresses Formation of Surplus Axons for Neuronal Polarity

Although neuronal functions depend on their robust polarity, the mechanisms that ensure generation and maintenance of only a single axon remain poorly understood. Using highly sensitive two-dimensional electrophoresis-based proteomics, we identified here a novel protein, single axon-related (singar)1/KIAA0871/RPIPx/RUFY3, which contains a RUN domain and is predominantly expressed in the brain. Singar1 expression became up-regulated during polarization of cultured hippocampal neurons and remained at high levels thereafter. Singar1 was diffusely localized in hippocampal neurons and moderately accumulated in growth cones of minor processes and axons. Overexpression of singar1 did not affect normal neuronal polarization but suppressed the formation of surplus axons induced by excess levels of shootin1, a recently identified protein located upstream of phosphoinositide-3-kinase and involved in neuronal polarization. Conversely, reduction of the expression of singar1 and its splicing variant singar2 by RNA interference led to an increase in the population of neurons bearing surplus axons, in a phosphoinositide-3-kinase-dependent manner. Overexpression of singar2 did not suppress the formation of surplus axons induced by shootin1. We propose that singar1 ensures the robustness of neuronal polarity by suppressing formation of surplus axons

Impact of residual in situ carcinoma on postoperative survival in 125 patients with extrahepatic bile duct carcinoma

Purpose: The aim of this study was to determine the impact of the presence of carcinoma in situ at the bile duct stump on postoperative survival in patients who underwent resection of extrahepatic bile duct carcinoma. Methods: The patients with resected extrahepatic bile duct carcinoma were divided into three groups according to resected margin status: no evidence of residual carcinoma (Negative group, n=96); carcinoma in situ at the bile duct stump (CIS group, n=10); and invasive carcinoma at any surgical margin (Invasive group, n=19). Cause-specific survival for these groups was compared statistically. Results: Surgical margin status was identified as a prognostic factor on univariate analysis (p=0.005) and was an independent prognostic factor on multivariate analysis (p=0.018). The CIS group displayed significantly better survival than the Invasive group (p=0.006), and the survival was comparable to that for the Negative group (p=0.533). Two of three patients in the CIS group with local recurrence died >5 years after surgical resection. Conclusions: Patients with positive ductal margins of carcinoma in situ of the extrahepatic bile duct do not appear to show different survival after resection compared to patients with negative margins, but remnant carcinoma in situ is likely to develop late local recurrence

Endoscopic retrograde cholangiography versus peroral cholangioscopy to evaluate intraepithelial tumor spread in biliary cancer

Background and study aims: Localized-type bile duct carcinoma (LBDC) is often accompanied by extensive intraepithelial tumor spread (ITS) ≥2 cm which makes radical resection more difficult. This retrospective case review compared the diagnostic accuracy of endoscopic retrograde cholangiography (ERC) and peroral cholangioscopy (POCS) to detect ITS beyond the visible LBDCs. Patients and methods: Forty-four consecutive LBDC patients diagnosed between April 2004 to October 2008 who underwent radical resection with histopathological analysis were included in this study. Extensive ITS was found histopathologically in one-third of the cases (32%). The outcome parameters were the presence or absence of extensive ITS and the extent of extensive ITS proximal and distal to the main tumor. Results: It was not possible to pass the cholangioscopic through the tumor sites in 6 cases. ERC correctly identified the presence of extensive ITS in 11/14 cases and did not yield any false-positive results. The three ERC-negative cases were all correctly identified by POCS plus biopsy since the cholangioscope could be passed in all three cases. The extent of extensive ITS was correctly diagnosed by ERC alone, ERC with POCS, and ERC with POCS plus mapping biopsy in 22%, 77%, and 100% of cases, respectively. Conclusions: The presence of extensive ITS could be correctly detected in 80% of cases by ERC alone. POCS with mapping biopsy provided perfect diagnostic accuracy of not only the presence/absence but also the extent of extensive ITS. However, POCS has the limitation that the cholangioscope cannot be passed through the tumor sites in approximately 15% of cases