Benign giant-cell tumor of the common bile duct:A case report

Primary giant-cell tumors rarely arise in the common bile duct. We herein report a case of primary giant-cell tumor of the common bile duct. The patient was an 81-year-old male who was diagnosed with a well-defined 1.2-cm mass projecting into the lumen of the middle common bile duct. Excision of the gallbladder and extrahepatic bile duct and a Roux-en-Y cholangiojejunostomy were performed. Histologically, the tumor had no association with carcinomas of epithelial origin and was similar to giant-cell tumors of the bone. The tumor consisted of a mixture of mononuclear and multinucleated osteoclast-like giant cells. The mononuclear cells showed no atypical features, and their nuclei were similar to those of the multinucleated giant cells. CD68 was expressed on the mononuclear and multinucleated osteoclast-like giant cells, whereas CD163 immunoreactivity was restricted to the mononuclear cells. Six months after the operation, the patient was still alive and had no recurrence. The interest of this case lies in the rarity of this entity, the difficulty of preoperative diagnosis, and this tumor’s possible confusion with other malignant tumors.

First principles study of stability, mechanical, and electronic properties of chromium silicides

Through the first principles calculations, the chemical stability, mechanical, and electronic properties of chromium silicides are predicted. Estimating enthalpies and binding energies, density state density and electron density distribution are combined to analyse the thermodynamic stability and physical properties of chrome-silicon binary compounds. The chromium silicide includes Cr3 Si, Cr5 Si3, CrSi, and CrSi2. The chemical stability and the information about electronic structure, mechanical properties, Debye temperature, and anisotropy properties are obtained by density functional theory and Debye quasi-harmonic approximation. Meanwhile, the calculation of elastic modulus shows that Cr3 Si has the highest body modulus value（251 GPa） and CrSi2 possesses the highest shear modulus（169.5 GPa） and Young＇s modulus（394.9 GPa）. In addition, the Debye temperature and the speed of sound of these Cr–Si compounds are also calculated.Since the calculated bulk modulus is different from Young＇s modulus anisotropy index, and also different from Young＇s modulus of a three-dimensional surface shape, the different mechanical anisotropies of all the compounds are obtained.

Effect of volume fraction of metal matrix composites framework on compressive mechanical properties of 3D interpenetrating ZTAp/40Cr architectured composites

The effect of the volume fraction of 3D-metal matrix composites(MMC)framework on the compressive properties of 3D interpenetrating hierarchical ZrO_(2)-toughened Al_(2)O_(3)particle(ZTAp)/40Cr steel composites was investigated.The results showed that the compressive properties of the material tended to decrease as the volume fraction of 3D-MMC framework increased.The composite with 35 vol.%3D-MMC had a yield strength of 1455.2 MPa and compressive strength of 1612.8 MPa,which occurred at a strain value of 5.6%.Compared to the homogeneously dispersed composite material,the composite with 35 vol.%3D-MMC had a 144.7%higher yield strength,which occurred at a 20%higher strain.An analysis of the cracks inside the material revealed that the crack was hindered and deflected by the matrix during propagation,which lengthened the crack propagation path and consumed more energy,thus leading to toughening.The results indicated that 3D interpenetrating hierarchical structure had a strengthening and toughening effect on ZTAp/40Cr composites.

Clinico-neuropathological features of isocitrate dehydrogenase 2 gene mutations in lower-grade gliomas

Background:Mutations in the isocitrate dehydrogenase 1(IDH1)and IDH2 genes are important for both the integrated diagnosis and the prognosis of diffuse gliomas.The p.R132H mutation of IDH1 is the most frequently observed IDH mutation,while IDH2 mutations were relatively rarely studied.The aim of the study was to determine the pathological and genetic characteristics of lowergrade gliomas that carry IDH2 mutations.Methods:Data from 238 adult patients with lower-grade gliomas were retrospectively analyzed.The status of IDH1/2 gene mutations,telomerase reverse transcriptase(TERT)promoter mutations,O^6-methylguanine-DNA-methyltransferase(MGMT)promoter methylation,1p/19q co-deletion and the expressions of IDH1 R132H,alpha-thalassemia X-linked mental retardation,and p53 were evaluated.Progression-free survival(PFS)and overall survival(OS)were calculated via Kaplan-Meier estimation using the log-rank test.Results:Totally,71%(169/238)of patients were positive for IDH mutations,including 12 patients harboring mutations in IDH2.Among the 12 patients with IDH2 mutations,ten patients harbored the R172K mutation,one patient harbored the R172S mutation and one harbored the R172W mutation.Of these,11 tumors occurred in the frontal lobe and showed morphology typical of oligodendroglioma.The proportion of grade II tumors was higher than that of grade III tumors in IDH2 mutant-gliomas.IDH2 mutations were frequently associated with TERT promoter mutations,1p/19q co-deletion and MGMT promoter methylation.IDH2 mutations were associated with better outcomes compared with IDH wild-type gliomas(P<0.05).However,the PFS and OS did not differ from that of IDH1 mutant patients(P=0.95 and P=0.60,respectively).Conclusions:IDH2 mutations are more frequent in oligodendrogliomas and associated with a better prognosis.IDH2 mutations may segregate in distinct clinico-pathological and genetic subtypes of gliomas,and therefore may merit routine investigation.

Deformation characteristic of semi-solid ZCuSn10 copper alloy during isothermal compression

The compression tests were carried out by Gleeble-1500 thermo-mechanical simulator with samples of semi-solid ZCuSnl0 alloy prepared by strain-induced melt activation （SIMA） process. The original microstruc- ture and the deformation temperature of semi-solid ZCuSnl0 alloy are different. The strain is 0.2, and the strain rate is 1 s-1 for the compression test. The results show that when the semi-solid ZCuSnl0 alloy was pre- pared by SIMA process, the liquid fraction of semi-solid microstructure increases, and the solid grain is smaller, more uniform and more inclined to be round as the roiling pre-deformation increasing. The results also indicate that the deformation resistance of ZCuSnl0 alloy in semi-solid state decreases with the deformation temperature increas- ing or the solid fraction of original microstructure de- creasing. The stress-strain curves of the isothermal compression can be divided into quasi-elastic deformation stage and plastic deformation stage, and there are three deformation zones in the samples after isothermal com- pression, namely the difficult deformation zone, the large deformation zone and the free deformation zone. In the three deformation zones, the main deformation mechanism is flow of liquid incorporating solid particles （FLS） mechanism, plastic deformation of solid particles （PDS） mechanism and liquid flow （LF） combining with FLS mechanism, respectively.

A Dandy-Walker malformation associated with ganglioglioma

To the Editor: The Dandy-Walker malformation (DWM) is a rare congenital malformation involving the posterior fossa. Diagnosis of the DWM is based on a series of characteristic neuroimaging findings, which include complete or partial agenesis of the cerebellar vermis, cystic dilatation of the fourth ventricle, and enlarged posterior fossa.[1] Several malformation syndromes and cytogenetic abnormalities have been associated with the DWM. However, the co-existence of the DWM and neoplasms is rare.[2] There are rare reports of the co-existence of the DWM and ganglioglioma.

Effect of Si content on impact-abrasive wear resistance of Al2O3p/steel composites prepared by squeeze casting

The 40Cr steel matrix composites were reinforced with Al203 particulates （Al2O3p） through Si adding to improve the impact-abrasive wear resistance, in which Si powder ranging up to 25% of the AlzO3p weight was added into the Al2O3p preforms; then, the composites were fabricated by squeeze casting. For all composites, alumina particles are evenly distributed, and Si powder is dissolved in the matrix. Without Si powder addition, the 40Cr steel matrix contains only pearlite; however, ferrite appears and increases with Si powder addition. In the impact-abrasive wear tests, the impact frequency is 80 min^-1 and the impacting energy is 2 J. With increasing Si powder, the wear of the composites first decreases obviously, reaches the minimum at 10% and then increases. The effect of Si addition on the wear resistance can be attributed to two reasons： one is increasing the hardness of the matrix, and the other is improving the interfacial bonding between Al2O3p and steel. The wear mechanism of the composites is abrasive wear when the Si powder is 〈 10 wt%. Otherwise, it is a mixed mode of abrasive and delamination wear.

Interhemispheric cistern lipoma associated with malformations of cortical development, hypogenesis of the corpus callosum, and abnormal vasculature

To the Editor:Intracranial lipomas(ICLs)are very rare congenital malformative lesions accounting for about 0.1%to 1.7%of all intracranial tumors.[1,2]Herein we describe a rare case of a lipoma affecting the cerebral interhemispheric cisterns in association with malformations of cortical development(MCD),hypogenesis of the corpus callosum,and abnormal vasculature.

Clinicopathological features of inflammatory demyelinating diseases in biopsy

Inflammatory demyelinating diseases(IDD)of the central nervous system(CNS)occur throughout the world and are the leading cause of nontraumatic neurological disability in young adults.[1]Early diagnosis of IDD allows prompt immunotherapies that minimize relapse,disabilities and mortality.[2]Multiple sclerosis(MS)is the most frequent IDD in adults.The histological characteristics of chronic MS lesions are well known to neuropathologists;however,diagnosing an inflammatory demyelinating process in biopsy may be challenging since the specimens are frequently small and often represent only parts of a larger lesion.[3]Furthermore,the histopathological hallmarks of acute MS differ fundamentally from the well-known characteristics of chronic demyelinated plaques observed in autopsies.[3]Kuhlmann et al[4]recently proposed a new histological classification system for MS lesions.Whether this new classification system corresponds to clinical manifestations and thus reflects the temporal multiplicity of MS and whether it can be applied to all IDD cases remain to be further studied.

Papillary Glioneuronal Tumor with an Excessive Angiomatous Component in an Elderly Man

Papillary glioneuronal tumor （PGNT） is a rare tumor categorized as a distinct mixed glioneuronal neoplasm in the World Health Organization （WHO） 2007 classification,rfl Here, we report a case of PGNT accompanied by excessive areas with angioma-like features in an elderly man. This report contributes to the diverse spectrum of this rare tumor entity.