Simultaneous occurrence of a hepatocellular carcinoma and a hepatic non-Hodgkin’s lymphoma infiltration

To investigate the simultaneous occurrence of hepatocellular carcinoma and non-Hodgkin’s lymphoma, we report the case of a 70 year old patient with a primary diagnosis of non-Hodgkin’s lymphoma in 2002. In a routine follow up investigation of his chronic lymphocytic leukemia a newly detected mass in the Couinaud's segments 2 and 3 was found. No hepatitis C virus or hepatitis B virus infection or cirrhosis was evident. After laparoscopic segmentectomy the histological examination revealed a hepatocellular carcinoma. While the relation between liver parenchyma damages and hepatocellular carcinoma or non-Hodgkin’s lymphoma is well known, only a few publications have focused on the coexistence of hepatocellular carcinoma and non-Hodgkin’s lymphoma. With this case we demonstrate the coexistence of these diseases without having a predamaged liver parenchyma

Impact of Duct-to-Mucosa Pancreaticojejunostomy with External Drainage of the Pancreatic Duct After Pancreaticoduodenectomy

Background. A variety of different techniques are established for the management of the pancreatic remnant after partial pancreaticoduodenectomy. Although pancreaticojejunostomy is one of the most favored methods, technical details are still under discussion. We report about a series of duct-to-mucosa pancreaticojejunostomies with total external drainage of the pancreaticduct. Patients and Methods. Between 1998 and 2007 257 patients underwent surgical therapy for malignant disease of the pancreas and the periampullary region and for chronic pancreatitis. Of these, 153 partial pancreaticoduodenectomies (85 pylorus preserving resections and 68 Whipple's procedures) were performed. In all of these cases, the pancreatic remnant was drained by a duct-to-mucosa pancreaticojejunostomy with external drainage of the pancreatic duct. Presence of postoperative pancreatic fistula (PPF) was defined according to the International Study Group on Pancreatic Fistula (ISGPF). Results. Postoperative mortality was 1.9%. The incidence of postoperative pancreatic fistula (PPF) was 19.6% according to the ISGPF criteria. Only one patient required re-laparotomy for complications caused by PPF. Patients with PPF had a significantly longer operation time (7.3 h versus 6.6 h; P = 0.041). Incidence of PPF was not influenced by histology. In all cases the fistulas resolved under conservative treatment. Conclusion. Duct-to-mucosa PJ with external drainage is a safe procedure to enteralize the pancreatic stump after partial pancreaticoduodenectomy. (C) 2011 Elsevier Inc. All rights reserved

Pyroclastic dune bedforms: macroscale structures and lateral variations. Examples from the 2006 pyroclastic currents at Tungurahua (Ecuador).

Pyroclastic currents are catastrophic flows of gas and particles triggered by explosive volcanic eruptions. For much of their dynamics, they behave as particulate density currents and share similarities with turbidity currents. They occasionally deposit dune bedforms with peculiar lamination patterns, from what is thought to represent the dilute, low concentration, and fluid-turbulence supported end member of the pyroclastic currents. Here, we present a high resolution dataset of sediment plates (lacquer peels) with several closely spaced lateral profiles representing sections through single pyroclastic bedforms from the August 2006 eruption of Tungurahua (Ecuador). Most of the sedimentary features contain backset bedding and preferential stoss-face deposition. From the ripple scale (few cm) to the largest dune bedform scale (several m length), similar patterns of erosive-based backset beds are evidenced. Recurrent trains of sub-vertical truncations on the stoss side of structures reshape and steepen the bedforms. In contrast, sporadic coarse-grained lenses and lensoidal layers flatten bedforms by filling troughs. The coarsest (clasts up to 10 cm), least sorted and massive structures still exhibit lineation patterns that follow the general backset bedding trend. The stratal architecture exhibits strong lateral variations within tens of centimeters, with very local truncations both in flow-perpendicular and flow-parallel direction. We infer that the bedforms' sedimentary patterns result from four formation mechanisms: "differential draping", "slope-influenced saltation", "truncative bursts", and "granular-based events". Whereas most of the literature makes a straightforward link between backset bedding and Froude-supercritical flows, we reconsider this interpretation. Indeed, features that would be diagnostic of subcritical dunes, antidunes, and "chute and pools" can be found on the same horizon and in a single bedform, only laterally separated by short distances (10s of cm). Our data stress the influence of the pulsating and highly turbulent nature of the currents and the possible role of coherent flow structures such as Görtler vortices. Backset bedding is interpreted here as a consequence of a very high sedimentation environment of weak and waning currents that interact with the pre-existing morphology. Quantification of near-bed flow velocities are made via comparison with wind tunnel experiments. We estimate that shear velocities of ca. 0.30 m.s-1 (equivalent to pure wind velocity of 6 to 8 m.s-1 at 10 cm above the bed) could emplace the constructive bedsets, whereas the truncative phases would result from bursts with impacting wind velocities of at least 30-40 m.s-1

Revisiting the lacquer peels method with pyroclastic deposits: sediment plates, a precise, fine scale imaging method and powerful outreach tool

Abstract Pyroclastic sedimentary successions record an eruptive history modulated by transport and depositional phases. Here, a field technique of outcrop impregnation was used to document pyroclastic sediments at the scale of individual laminae. The details so obtained have the potential to reveal new insights into the dynamics of transport and deposition of pyroclastic currents and fallout. Sediment plates (a type of lacquer peels) represent a sampling method whereby a thin plate of undisturbed sediments is obtained directly from the outcrop. A low-viscosity, hardening epoxy resin is applied to a freshly exposed cross-section of an unconsolidated deposit and impregnates a surface layer of the cross-section via capillary forces before solidifying. Upon hardening, a solid plate (0.5–5 cm thick and up to 2 m in length) of the sedimentary formation can be recovered and transported with full preservation of the initial organization of the particles. Sediment plates are capable of recording and highlighting details of stratification to a very fine scale and high degree of precision. This method represents a valuable tool for research, education, and exhibition purposes. A dataset of 50 m2 of sediment plates was created from the primary sedimentary structures emplaced during 1) the August 2006 eruption of Tungurahua volcano (Ecuador), 2) the Laacher See eruption (Germany) and 3) Astroni surge deposits (Campi Flegrei, Italy). This dataset has been put to use in several contexts: 1) analysis of sedimentation processes at the boundary-layer scale, 2) data comparison with remote measurements (e.g., ground penetrating radar), 3) archiving and conservation, 4) as teaching material and 5) for dissemination exercises during exhibition in museums

Pyroclastic dune bedforms: macroscale structures and lateral variations. Examples from the 2006 pyroclastic currents at Tungurahua (Ecuador).

Pyroclastic currents are catastrophic flows of gas and particles triggered by explosive volcanic eruptions. For much of their dynamics, they behave as particulate density currents and share similarities with turbidity currents. They occasionally deposit dune bedforms with peculiar lamination patterns, from what is thought to represent the dilute, low concentration, and fluid-turbulence supported end member of the pyroclastic currents. Here, we present a high resolution dataset of sediment plates (lacquer peels) with several closely spaced lateral profiles representing sections through single pyroclastic bedforms from the August 2006 eruption of Tungurahua (Ecuador). Most of the sedimentary features contain backset bedding and preferential stoss-face deposition. From the ripple scale (few cm) to the largest dune bedform scale (several m length), similar patterns of erosive-based backset beds are evidenced. Recurrent trains of sub-vertical truncations on the stoss side of structures reshape and steepen the bedforms. In contrast, sporadic coarse-grained lenses and lensoidal layers flatten bedforms by filling troughs. The coarsest (clasts up to 10 cm), least sorted and massive structures still exhibit lineation patterns that follow the general backset bedding trend. The stratal architecture exhibits strong lateral variations within tens of centimeters, with very local truncations both in flow-perpendicular and flow-parallel direction. We infer that the bedforms' sedimentary patterns result from four formation mechanisms: "differential draping", "slope-influenced saltation", "truncative bursts", and "granular-based events". Whereas most of the literature makes a straightforward link between backset bedding and Froude-supercritical flows, we reconsider this interpretation. Indeed, features that would be diagnostic of subcritical dunes, antidunes, and "chute and pools" can be found on the same horizon and in a single bedform, only laterally separated by short distances (10s of cm). Our data stress the influence of the pulsating and highly turbulent nature of the currents and the possible role of coherent flow structures such as Görtler vortices. Backset bedding is interpreted here as a consequence of a very high sedimentation environment of weak and waning currents that interact with the pre-existing morphology. Quantification of near-bed flow velocities are made via comparison with wind tunnel experiments. We estimate that shear velocities of ca. 0.30 m.s-1 (equivalent to pure wind velocity of 6 to 8 m.s-1 at 10 cm above the bed) could emplace the constructive bedsets, whereas the truncative phases would result from bursts with impacting wind velocities of at least 30-40 m.s-1