Deep-seated Mass Research Articles

Appraise the structural mitigation of landslide risk via numerical modelling: a case study from the northern Apennines (Italy)

The Ca’ Lita landslide is a large and deep-seated mass movement located in the northern Apennines, about 70 km west of Bologna (Northern Italy). It consists of a composite landslide that affects Cretaceous to Eocene flysch rock masses and chaotic complexes. Many of the sectors making up the landslide have resumed activity between 2002 and 2006, threatening some villages and an important road connecting several key industrial facilities located in the upper watershed. This paper presents the management of the emergency, dealing with the investigation campaigns (geological, geomorphological and LiDAR surveys, borehole drillings, seismic surveys), with the monitoring (in situ instrumentation) and with the design and construction of mitigation measures. The whole process, from landslide reactivation to date, has been modelled on a numerical basis with the finite difference code FLAC 2D, to assess the efficiency of the mitigation system and to propose further countermeasure works in different scenarios.

Sclerosing epithelioid fibrosarcoma as a rare cause of ascites in a young man: a case report

IntroductionSclerosing epithelioid fibrosarcoma is a rare but distinct variant of fibrosarcoma that not only presents as a deep-seated mass on the limbs and neck but can also occur adjacent to the fascia or peritoneum, as well as the trunk and spine. We report the case of an intra-abdominal sclerosing epithelioid fibrosarcoma, which to best of the authors' knowledge has not been described previously. The patient discussed here developed lung metastases but is still alive 1-year post-diagnosis.Case presentationA 29-year-old man presented with a 2-week history of progressive abdominal distension and pain and was found to have marked ascites. A full liver screen was unremarkable with abdominal and chest computed tomography scans only confirming ascites. After a diagnostic laparotomy, biopsies were taken from the greater omentum and peritoneal nodules. Histopathology revealed a malignant tumour composed of sheets and cords of small round cells set in collagenized stroma. After further molecular investigation at the Mayo Clinic, USA, the diagnosis of a high-grade sclerosing epithelioid fibrosarcoma was confirmed.ConclusionSclerosing epithelioid fibrosarcoma is an extremely rare tumour, which is often difficult to diagnose and which few pathologists have encountered. This case is particularly unusual because of the intra-abdominal origin of the tumour. Owing to the rarity of sclerosing epithelioid fibrosarcoma, there is no clear evidence regarding the prognosis of such a tumour, although sclerosing epithelioid fibrosarcoma is able to metastasize many years post-presentation. It is important that physicians and pathologists are aware of this unusual tumour.

Intramuscular Myxoma Presenting as a Rare Posterior Neck Mass in a Young Child

Intramuscular myxoma (IMM) is an uncommon benign tumor that presents as a slow-growing, deep-seated mass confined to the skeletal muscle. Histologically, these lesions most resemble umbilical cord tissue. They are generally found in the proximal thigh, gluteal region, or shoulder girdle and are exceedingly rare neck masses in the pediatric population. These tumors most often present as painless, deep-seated intramuscular masses that may exhibit symptoms of compression of surrounding structures.(1) I report a case of a 22-month-old girl with an IMM in the posterior cervical triangle.

Investigation and monitoring in support of the structural mitigation of large slow moving landslides: an example from Ca' Lita (Northern Apennines, Reggio Emilia, Italy)

Abstract. The Ca' Lita landslide is a large and deep-seated mass movement located in the Secchia River Valley, in the sector of the Northern Apennines falling into Reggio Emilia Province, about 70 km west of Bologna (Northern Italy). It consists of a composite landslide system that affects Cretaceous to Eocene flysch rock masses and chaotic complexes. Many of the components making up the landslide system have resumed activity between 2002 and 2004, and are now threatening some hamlets and an important road serving the upper watershed area of River Secchia, where many villages and key industrial facilities are located. This paper presents the analysis and the quantification of displacement rates and depths of the mass movements, based on geological and geomorphological surveys, differential DEM analysis, interpretation of underground stratigraphic and monitoring data collected during the investigation campaign that has been undertaken in order to design cost-effective mitigation structures, and that has been conducted with the joint collaboration between public offices and research institutes.

Numerical analysis of deep-seated mass movements in the Magura Nappe; Flysch Belt of the Western Carpathians (Czech Republic)

Abstract. Deep-seated slope failures are common features in the mountains of the Raca Unit, Magura Nappe of the Flysch Belt of Western Carpathians. Since they represent very complicated system, understanding of their evolution and triggers still remains unclear. We tried to provide a back-analysis of their development by using a finite difference code (FDM) of continua (Flac 4.0). We confirmed that such large mass movements could be triggered by water saturation of the bedrock in the three particular geological and geomorphic settings. Such situation could have been caused by heavy rainfalls in humid phases of the Holocene or permafrost melting in Late Glacial. The effects of faulting, very deep weathering of the bedrock, low geotechnical parameters of smectite-rich material and the local slope geometry have also been accounted for in numerical models, as well as the other triggering factors of slope instability. FDM modelled shear zones are in agreement with observations.

Forearm Mass in an Adolescent

Forearm Mass in an Adolescent

Structure and dynamics of deep-seated slope failures in the Magura Flysch Nappe, outer Western Carpathians (Czech Republic)

Abstract. Deep-seated mass movements currently comprise one of the main morphogenetic processes in the Flysch Belt of the Western Carpathians of Central Europe. These mass movements result in a large spectrum of slope failures, depending on the type of movement and the nature of the bedrock. This paper presents the results of a detailed survey and reconstruction of three distinct deep-seated slope failures in the Raca Unit of the Magura Nappe, Flysch Belt of the Western Carpathians in the Czech Republic. An interdisciplinary approach has enabled a global view of the dynamics and development of these deep-seated slope failures. The three cases considered here have revealed a complex, poly-phase development of slope failure. They are deep-seated ones with depths to the failure surface ranging from 50 to 110m. They differ in mechanism of movement, failure structure, current activity, and total displacement. The main factors influencing their development have been flysch-bedrock structure, lithology, faulting by bedrock separation (which enabled further weakening through deep weathering), geomorphic setting, swelling of smectite-rich clays, and finally heavy rainfall. All of the slope failures considered here seem to have originated during humid phases of the Holocene or during the Late Glacial.

Angiosarcoma arising in hemangioma/vascular malformation: report of four cases and review of the literature.

Malignant change in a benign vascular tumor is exceedingly rare, and there have been only five previously reported convincing cases. Four new cases of angiosarcoma (AS) arising in a hemangioma/vascular malformation (HVM) are described. All patients were in the 6th or 7th decade of life (two female, two male). Development of an enlarging deep-seated mass was the main presenting symptom. MRI disclosed the presence of two separate soft tissue masses in both thighs in one patient. No patient had a history of prior radiotherapy at the same site. Preoperative duration, known in three cases, ranged from 1 to 24 months (median 12 months). Three tumors were located in the lower extremities (thigh and buttock), one in the retroperitoneum, and one in the parotid region. Three patients were treated by marginal excision; in one case only a biopsy was performed. Radiotherapy/chemotherapy was given in all cases. Two patients were disease free 2 and 14 months after surgery and two developed metastases. Grossly, the tumors were described as frankly hemorrhagic masses or as firm, whitish areas with hemorrhagic nodules and were centered in skeletal muscle in three cases. Size ranged between 2.2 cm and 8 cm (median 4.3 cm). Histologically, all the tumors had two distinct components. In three cases the benign and the malignant components were variably intermixed, whereas in one case the HVM was mainly located at the edge of the malignant tumor. The benign component showed features of an arteriovenous hemangioma (three cases) or intramuscular capillary hemangioma. AS showed epithelioid morphology in three cases and a well-differentiated dissecting pattern in one case. An imperceptible transition between the two components was noted in two cases. The two anatomically separate masses excised from one patient appeared almost identical. All cases were positive for at least two endothelial markers (CD31, CD34, VWF) and negative for the epithelial markers (EMA, AE1/AE3, Pan-keratin). Possible mechanisms for this exceptional phenomenon are discussed.

Clinical Experiences in Neuronavigation

We have successfully used a navigation system in more than 120 neurosurgical operations for past two years. The neuronavigation system provides high levels of mechanical accuracy in surgical localization, especially for small deep-seated masses or epileptic foci, surgical planning for intrinsic and extrinsic brain tumors, and arteriovenous malformation and guidance of instrumentation of spinal surgery. The ages of the patients were from 12 months to 75 years. The sex distribution was equal. Computed tomography or magnetic resonance imaging with 2–3 mm thick slices were employed for image guidance. The clinical experiences included 50 cases of deep-seated mass, 50 cases of surgical planning for tumor or vascular mass excision and 20 cases of spinal instrumentation treatment. There were no mechanical failures. Neuronavigation definitely provides a good technology in frameless brain and spinal surgeries.

219 大深度地殻エネルギー抽出のための花こう岩と超臨界水との相互作用に関する研究

219 大深度地殻エネルギー抽出のための花こう岩と超臨界水との相互作用に関する研究

Relationships between clay mineralogy, hydrothermal metamorphism, and topography in a Western Cascades watershed, Oregon, USA

This study investigates variation in clay mineralogy and its relation to hydrothermal metamorphism, hillslope processes, and topography in the western Cascade Mountains. The study area is the drainage basin of Dorena Lake, a medium-sized (686 km 2) watershed located near Cottage Grove, OR. The Bohemia Mining District is on the southeastern rim of the watershed in a hydrothermally metamorphosed region associated with a set of granodiorite plutons. To characterize large-scale patterns of clay mineral distribution within the watershed, suspended sediments were collected from 43 stream locations. Samples of several metamorphosed and unaffected volcanic and volcaniclastic rocks were collected to help clarify metamorphic reaction processes. One active earthflow was also sampled. X-ray diffraction methods were used to determine the mineralogy of the clay-sized (<2 μm) fraction of the samples. Clay mineralogy varies systematically across the watershed, and the three major stream tributaries carry sediment with distinct mineralogical signatures. Discrete minerals include kaolinite, smectite, chlorite, and illite. Interstratified kaolinite–smectite and chlorite-vermiculite (CV) are also present. The active earthflow and unmetamorphosed rock samples primarily contain smectite. In contrast, metamorphosed rock samples are composed of some combination of illite, interstratified illite–smectite, CV, and chlorite. Examination of clay mineral distribution reveals the effects of hydrothermal metamorphism in the mining district on clay mineralogy, hillslope processes, and landscape development. Compared with most of the watershed, the mining district has steeper slopes and higher elevations and lacks smectite almost entirely. Analyses of metamorphosed bedrock units indicate that smectite originally present in the rocks was converted to nonexpandable clay minerals during metamorphism. Induration of bedrock and loss of expandable clays resulted in thin soils and steep topography. Debris slides and flows are the dominant mass movement processes in this area; earthflows are noticeably absent, probably because thick, smectitic soils are lacking. Elsewhere in the watershed where smectite is abundant, slopes are more gentle; and both shallow and deep-seated mass movements are common. The clay mineralogy of bedrock and soils is thus integrally tied to the hillslope processes operating within the watershed and therefore affects the geomorphology of the landscape. High-relief, hydrothermally metamorphosed volcanic centers surrounded by weaker rocks in adjacent lowlands are common features in the western Cascade Mountains. These massifs were likely formed by differential erosion processes similar to those operating in the Dorena Lake watershed.

455 大深部岩体における水圧破砕き裂進展プロセスの数値シミュレーションに関する研究(GS-12 き裂(3))

455 大深部岩体における水圧破砕き裂進展プロセスの数値シミュレーションに関する研究(GS-12 き裂(3))

Deep-seated thoracic and abdominal masses: usefulness of ultrasound and computed tomography guidance in fine needle aspiration cytology diagnosis.

Fine needle aspiration cytology (FNAC) was performed under ultrasound and CT guidance in 120 cases. These included abdominal masses (85 cases) and thoracic masses (35 cases) biopsied over a two and a half year period (March 1996 to September 1998). The aim of this study was to assess the contribution of clinico-imaging evaluation and image-guided FNAC to the management of patients with deep-seated mass lesions. Aspirations in the abdomen were performed from various anatomic sites such as liver (56 cases), lymph nodes (18 cases), gastrointestinal tract (three cases), pancreas (six cases), and kidney (two cases). In the thorax, biopsy was performed in the lung (19 cases) and mediastinum (13 cases). In 112 cases (93.4%) FNAC was diagnostic. Of the lesions that were successfully aspirated, 85% were < or = 5 cm in size. No major complication was encountered. All the successful aspirates could be defined as malignant or non-malignant, but tissue differentiation was possible in 63.7% of malignant lesions and 53.8% of benign lesions. Combined clinical and imaging evaluation for malignancy showed 80% sensitivity and 59% specificity. Although clinicoradiological parameters themselves have certain limitations in diagnosing benign versus malignant lesions, in conjunction with guided FNA they are very accurate and safe in diagnosing deep-seated mass lesions in the thorax and in the abdomen. However, the role of FNA in tissue differentiation of solid lesions such as lymphoma requires further study.

Incidental sampling of branchial remnants: A potential source of error in fine-needle aspiration of neck lesions—a case report

Remnants of the branchial apparatus can produce lesions in the head and neck region in later life, often amenable to fine-needle aspiration (FNA) diagnosis. Yet such remnants or rudimentary lesions can remain clinically undetected and can later interfere with the cytologic interpretation of other deep lesions of the neck, as the present case demonstrates. In this case the lesion, which by a subsequent resection turned out to be a neurilemmoma, had been adequately sampled by the FNA, yet the cytologic diagnosis was sidetracked by the presence in the specimen of immature squamous epithelial tissue fragments and other elements (multinucleated histiocytes, calcifications), on the basis of which the diagnosis of an epithelial lesion, likely malignant, was made. The neck surgery and a preceding endoscopic examination of the mouth, pharynx, and larynx did not identify such a lesion, but a detailed microscopic examination of the fibroadipose tissue between the tumor and the peripharyngeal region revealed the presence of epithelial microfragments with morphology partly corresponding to that of the FNA cytology, highly indicative of a branchiogenic lesion in the peripharyngeal region. The basic embryology of the branchial apparatus resulting in such defects is presented, as well as tentative guidelines for recognizing material deriving from accidental sampling of such lesions during FNA investigations of deep-seated masses of the neck. Diagn. Cytopathol. 2000;22:157–160. © 2000 Wiley-Liss, Inc.

The influence of the Earth's gravity anomoly boundary effects upon the landscape elements

Conditions are investigated of generation of additional components, both normal and horizontal, of the gravity force acceleration above the gravity anomalies on the Earth's surface. Gravity force variations along the Earth's surface have been evaluated quantitatively for a spherical mass. The distributions and amplitudes of the horizontal components of the gravity caused by deep-seated masses of complicated geometry have been under consideration. A qualitative approach to processes acting on landscape structures in fringe zones of the gravity anomalies has been carried out by synthetic models. Analytical calculation were put together with the results of synthetic modelling and compared with field observations and remote sensing studies.

Spectral methods in gravity inversion: the geopotential field and its derivatives

The 3D spectral analysis of the gravitational potential field for a given mass distribution is studied. The derived quantities, the gravitational force field and the gravity gradient tensor are computed in frequency space. As an example, the fields are theoretically and numerically evaluated for a right rectangular prism. The spectral approach finds several geophysical applications, as, e.g., in inversion processes. Gravity inversion for deep seated masses, as for instance at Moho level, are treated with an iterative inversion process, in which the downward continuation is alternated with the classical calculation of the gravity field. The theory is applied to the inversion of the gravity data in the SE-Alps, regarding only the long-period field, generated by Moho undulations. The results are used for the evaluation of the equipotential lines, the gravity field, and the gravity gradient tensor in a vertical section of the Alpine crustal root.

Coupling GIS with Physical Models to Assess Deep-Seated Landslide Hazards

Deep-seated landslides pose a dilemma for land managers who must utilize certain natural resources while protecting others from adverse environmental impacts. The physical factors controlling deep-seated mass movement are often poorly constrained, and the consequences of a particular land use may therefore be unknown. Empirical techniques work well for mapping areas affected by deep-seated landsliding, but may be incapable of predicting the impacts of land use on specific landslides. Numerical models of the physical processes of mass movement offer an alternative method for determining landslide potential and provide additional information for evaluating hazards where empirical evidence is insufficient or ambiguous. Modeling efforts can utilize topographic and geotechnical data mapped at regional scales (typically 1:24,000) if the physical controls on landsliding are resolved. A strategy for coupling the data processing capabilities of geographic information systems (GIS) software with the predictive power of a physical model is demonstrated with a small basin in northwestern Washington state, managed for timber production, where deep-seated landsliding has degraded an important fisheries resource. Historic data were insufficient to clearly identify the primary factors controlling landslide activity. Modelling results, however, indicate that certain deep-seated landslides react primarily to increases in pore-water pressure, while others react primarily to stream-channel incision. These results guide further field efforts and provide a rational basis for land-use decisions.

Postauricular response in motor paresis with intracranial lesions.

The clinical usefulness of the postauricular response (PAR) in the evaluation of motor paresis was studied in 105 patients with intracranial lesions and 25 normal volunteers. Click stimuli at 90 dB hearing level were delivered in each ear, and PARs recorded from bilateral posterior auricular muscles with reference to the vertex (Cz). No volunteer demonstrated PAR in the relaxed posture, but in tensed postures increasing muscle tone PARs were elicited with a latency of 11.5 +/- 0.7 msec and an amplitude of 6.2 +/- 2.8 muV. Sixty-two patients (59%) had high-amplitude PARs in the relaxed posture. PARs were enhanced more frequently in paretic patients than in non-paretic patients (p less than 0.01). In subcortical lesions, the PAR latency had a significant correlation with the degree of motor paresis (p less than 0.005). In patients, the enhanced PAR amplitude suggested the presence of motor paresis associated with deep-seated mass lesions. The enhanced response is thought to be associated with dysfunction of the pyramidal and extrapyramidal tracts.

Open surgery assisted by the neuronavigator, a stereotactic, articulated, sensitive arm

A new computed tomographic-stereotactic device that translates the operating point onto preoperative computed tomographic (CT) images, the Neuronavigator, has been developed. We have applied this system to various neurosurgical procedures to examine its usefulness. The system consists of a 6-joint sensing arm and a 16-bit personal computer. It projects the location of the arm tip onto a corresponding CT slice with a cursor that guides the surgeon toward the intracranial target during open surgery. The system also projects the location of the tip onto angiograms, and when used in conjunction with echography or a transcranial Doppler (TCD) flow meter, the surgeon's ability to navigate is enhanced. Sixty-eight patients underwent operation with the Neuronavigator. The navigation system worked as the core of a multimodal three-dimensional data base that proved to be useful during surgery. The maximum detection error was 2.5 mm, which was considered sufficient for open microsurgery. It also proved useful in designing the position of a craniotomy, in targeting deep-seated mass lesions, and in tracing the tumor edge, which had been identified on a CT scan. When the angiogram was combined with the navigator, it became easy to identify key vessels within a small operating field. The system was also combined with a TCD flow meter. This combination makes it possible to translate the measuring point of the TCD directly into CT coordinates, improving the precision of location of the TCD probe. The Neuronavigator combines various diagnostic images into one database and effectively guides the surgeon during surgery.

Open Surgery Assisted by the Neuronavigator, a Stereotactic, Articulated, Sensitive Arm

Abstract A new computed tomographic-stereotactic device that translates the operating point onto preoperative computed tomographic (CT) images, the Neuronavigator, has been developed. We have applied this system to various neurosurgical procedures to examine its usefulness. The system consists of a 6-joint sensing arm and a 16-bit personal computer. It projects the location of the arm tip onto a corresponding CT slice with a cursor that guides the surgeon toward the intracranial target during open surgery. The system also projects the location of the tip onto angiograms, and when used in conjunction with echography or a transcranial Doppler (TCD) flow meter, the surgeon's ability to navigate is enhanced. Sixty-eight patients underwent operation with the Neuronavigator. The navigation system worked as the core of a multimodal three-dimensional data base that proved to be useful during surgery. The maximum detection error was 2.5 mm, which was considered sufficient for open microsurgery. It also proved useful in designing the position of a craniotomy, in targeting deep-seated mass lesions, and in tracing the tumor edge, which had been identified on a CT scan. When the angiogram was combined with the navigator, it became easy to identify key vessels within a small operating field. The system was also combined with a TCD flow meter. This combination makes it possible to translate the measuring point of the TCD directly into CT coordinates, improving the precision of location of the TCD probe. The Neuronavigator combines various diagnostic images into one database and effectively guides the surgeon during surgery.