Clear cell carcinoma of the stomach: a rare tumor variant imparting poor prognosis.

INTRODUCTION: Clear cell gastric cancer (CCGC) represents an extremely rare variant of adenocarcinoma of the stomach. It can be mistaken for a clear cell metastatic lesion arising from other anatomic parts, especially renal cell carcinoma. PATIENTS AND METHODS: We describe the case of a 66-year-old woman who was operated for a pyloric adenocarcinoma which resulted to be a CCGC at definitive histology. Moreover, we offer a systematic review of the current pertinent literature on CCGC. RESULTS: Our case represents the 160th example of CCGC. Clear cell aspect is due to the intracytoplasmic accumulation of glycogen in most cases, followed by mucin, lipid or water; the reason of the underlying biochemical process is still unclear. Paralleling other epithelial clear cell malignancies (as ovarian, bladder, urothelial or pancreatic cancers), also CCGC shows a more aggressive clinical behavior over conventional neoplastic counterparts. CONCLUSIONS: Differently from clear cell carcinomas involving other organs, CCGC has been rarely investigated by the literature. Since, compared to non clear cell cancers, this particular phenotype of gastric cancer appears to be associated with poorer prognosis, further studies are needed in order to corroborate its real adverse prognostic significance and standardize the correct management and treatment.

An unusual case of extra-nodal interdigitating dendritic cell neoplasm: sarcoma or not?

INTRODUCTION: Interdigitating dendritic cell sarcoma (IDCS) represents an extremely rare neoplasm frequently originating from T-cell- associated dendritic antigen-presenting cells normally populating the paracortex of lymph nodes. Diagnosis is challenging due to the rarity of this neoplasm and the overlapping features with the other primary and metastatic spindle cell neoplasm, even more, when localized in an extra-nodal site. PATIENTS AND METHODS: Herein we report a case of 48 Years old woman with a six-month history of centimetric, quiet painful mass of the philtrum without other significant comorbidity. RESULTS: Histological report showed a proliferation of quiet bland spindle to plump cell, scattered multinucleated giant cell in a subtle background of lymphocytes. IHC study displays only positivity for S-100 and fine, granular scattered cytoplasmatic stain for CD68; all dendritic IHC markers were negative. Morphological and immunohistochemical analyses were consistent with extra-nodal Interdigitating Dendritic Cell Neoplasm. CONCLUSION: Interdigitating Dendritic Cell Sarcoma is a rare and challenging entity with a variable prognosis. We present a case of extra-nodal IDCS whit low worrisome histological features, emphasizing the need for further efforts to better definitely this rare neoplasm ad its potential for malignancy.

Predictive role of dynamic contrast enhanced T1-weighted MR sequences in pre-surgical evaluation of macroadenomas consistency.

PURPOSE: Our hypothesis was that pituitary macroadenomas show different areas of consistency detectable by enhanced magnetic resonance imaging (MRI) with Dynamic study during gadolinium administration. MATERIALS AND METHODS: We analysed 21 patients with pituitary macroadenomas between June 2013 and June 2015. All patients underwent trans-sphenoidal surgery and neurosurgeon described macroadenomas consistency. Similarly, two neuroradiologists manually drew regions of interest (ROIs) inside the solid-appearing portions of macroadenoma and in the normal white matter both on dynamic and post-contrast acquisitions. The ratio between these ROIs, defined as Signal Intensity Ratio (SIR), allowed obtaining signal intensity curves over time on dynamic acquisition and a single value on post-contrast MRI. SIR values best differentiating solid from soft macroadenoma components were calculated and correlated with pathologic patterns. A two-sample T test and empiric receiver operating characteristic (ROC) curve of SIR was performed. RESULTS: According to ROC analysis, the SIR value of 1.92, obtained by dynamic acquisition, best distinguished soft and hard components. All the specimens from soft components were characterized by high cellularity, high representation of vascularization and micro-haemorrhage and low percentage of collagen content. The reverse was evident in hard components. CONCLUSIONS: We demonstrated that dynamic MRI acquisition could distinguish with good accuracy macroadenomas consistency.

Isolated Hypoglossal Nerve Palsy Mimicking a Base of Tongue Tumor.

Isolated paralysis of hypoglossal nerve is uncommon, generally being associated with other neuropathies. A careful differential diagnosis is necessary to recognize the underlying diseases, some of which can be life-threatening. The authors report a patient of an 80-year-old woman presenting with an isolated hypoglossal palsy, mimicking a tongue neoplasm. Through a careful clinical workup and thanks to the aid of the imaging, it was possible to identify the presence of signal alterations due to a subacute denervation of the affected hemitongue and to exclude the presence of a tumor. The patient was clinically diagnosed as isolated hypoglossal palsy, resulting from a thrombo-embolic accident involving the nerve along its course. The authors propose some useful means for the differential diagnosis and review the literature.

Predictive value of pre-treatment apparent diffusion coefficient (ADC) in radio-chemiotherapy treated head and neck squamous cell carcinoma.

OBJECTIVE: This study aimed at evaluating the role of "baseline" apparent diffusion coefficent (ADC), in patients affected by head and neck cancer treated with radio-chemotherapy, as a potential marker of response to therapy. METHODS: Fifty-seven patients underwent pretreatment ADC maps. Minimum, maximum, and medium ADC were computed. Age, dose, treatment time, and ADC values were compared between the two groups (Group 1: local control; Group 2: relapse/persistence of disease) using the Student t test two-tailed unpaired. Two-tailed Fischer exact test was used to compare T stage, N stage, grading and type of treatment between two groups. We have analyzed the receiver operating characteristic (ROC) of statistically significant variables. RESULTS: In patients with local control, values of pre-treatment medium and minimum ADC were lower than ADC values of patients with persistent or recurrent disease, with values, respectively, of 0.83 ± 0.02 × 10-3 mm2/s and 0.59 ± 0.02 × 10-3 mm2/s (vs 0.94 ± 0.05 × 10-3 mm2/s and 0.70 ± 0.05 × 10-3 mm2/s). ROC curve analysis displayed statistical significance as regarding the medium ADC value, showing a sensitivity of 50% and a specificity of 84.8%. ROC analysis of the values minimum ADC showed a sensitivity of 42.9% and specificity of 87.9%. CONCLUSION: The value of the ADC pre-treatment of patients with local control of the disease is lower than that of patients with persistent disease or recurrence.

Endovascular treatment of spontaneous extraperitoneal haemorrhage: immediate and long-term clinical efficiency.

PURPOSE: This study aimed to evaluate the effectiveness of transcatheter embolisation in the treatment of spontaneous extraperitoneal haemorrhage (SEH). MATERIALS AND METHODS: We retrospectively evaluated the technical and clinical success in terms of immediate and long-term mortality in a series of patients who underwent endovascular treatment of SEH from January 2005 to December 2010. A statistical comparison of pre- and postoperative transfusion requirements was performed by using the Student's t test, with statistical significance set at p < 0.005. RESULTS: In the period considered, 30 patients (16 women and 14 men; mean age, 73.3 years ±15.6) with SEH underwent endovascular treatment. Technical success was obtained in all cases (100 %), and a statistically significant reduction in blood transfusion requirements was observed (mean preoperative requirement: 7.5 U/day ±3; mean postoperative requirement 2.8 U/day) (p < 0.005). We observed a postoperative mortality of 10 % (3/30 patients) and mortality at 6 and 12 months was 14.8 % (4/27 patients) and 26 % (6/23 patients), respectively. CONCLUSION: According to our experience and to the literature, transcatheter arterial embolisation represents the treatment of choice in patients with SEH, as it ensures complete therapeutic success.

Endovascular treatment of intracranial aneurysms with flow-diverter stents: preliminary single-centre experience.

PURPOSE: This paper reports our preliminary experience with the endovascular treatment of intracranial aneurysms using flow-diverter stents (FDs) and compares it with the literature data. MATERIALS AND METHODS: From May 2009 to April 2012, 28 patients (6 men and 22 women; mean age, 54 years) with a total of 35 aneurysms were treated with FDs. We evaluated postprocedural technical success and long-term efficacy, with follow-up examinations performed at 3-7 days [computed tomography (CT)/magnetic resonance (MR) angiography] and at 3, 6 and 12 months (digital subtraction angiography, DSA). A total of 43 FDs were placed, 36 Pipeline and 7 Silk. RESULTS: A total of 30 procedures were performed (two patients were treated twice). Technical success was 96.6%, with one case of postprocedural death; the aneurysm exclusion rate at 3, 6 and 12 months was 60%, 73% and 89%, respectively. There was no case of acute stent thrombosis, and only two cases of nonsignificant stenosis. All covered side branches were patent, except one case of steno-occlusion of the ophthalmic artery. CONCLUSIONS: Our results are consistent with the literature and demonstrate the effectiveness and safety of FDs in selected cases of cerebral aneurysm (wide neck, fusiform, blister-like).

Ongoing Challenges of Laser-Based Powder Bed Fusion Processing of Al Alloys and Potential Solutions from the Literature-A Review.

Their high strength-to-weight ratio, good corrosion resistance and excellent thermal and electrical conductivity have exponentially increased the interest in aluminium alloys in the context of laser-based powder bed fusion (PBF-LB/M) production. Although Al-based alloys are the third most investigated category of alloys in the literature and the second most used in industry, their processing by PBF-LB/M is often hampered by their considerable solidification shrinkage, tendency to oxidation, high laser reflectivity and poor powder flowability. For these reasons, high-strength Al-based alloys traditionally processed by conventional procedures have often proved to be unprintable with additive technology, so the design and development of new tailored Al-based alloys for PBF-LB/M production is necessary. The aim of the present work is to explore all the challenges encountered before, during and after the PBF-LB/M processing of Al-based alloys, in order to critically analyse the solutions proposed in the literature and suggest new approaches for addressing unsolved problems. The analysis covers the critical aspects in the literature as well as industrial needs, industrial patents published to date and possible future developments in the additive market.

Sol-gel derived 45S5 bioglass: synthesis, microstructural evolution and thermal behaviour.

In this work, the 45S5 bioactive glass was synthesized through an aqueous sol-gel method. Characteristic functional groups were evidenced by Fourier transform infrared spectroscopy, the thermal behaviour was investigated by thermogravimetric and differential thermal analysis, crystallization kinetics and phase evolution were followed by X-ray diffraction measurements. The sintering behaviour of the sol-gel derived 45S5 was then studied by dilatometry and the microstructural evolution was followed step-by-step, interrupting the thermal cycle at different temperatures. In vitro dissolution tests were performed in order to assess the degradation behaviour of sol-gel derived 45S5 samples thermally treated at different temperatures. A relevant influence of the calcination conditions (namely, dwelling time and temperature) of the as-prepared powder on the phase appearance and its sintering behaviour as well as on the porosity features, in terms of pore dimension and interconnectivity, of the fired materials was stated.

Production of Dense Cu-10Sn Part by Laser Powder Bed Fusion with Low Surface Roughness and High Dimensional Accuracy.

Tin-bronze alloys with a tin content of at least 10 wt% have excellent mechanical properties, wear resistance, and corrosion resistance. Among these alloys, Cu-10Sn was investigated in this study for production with the laser powder bed fusion process with a 500W Yb:YAG laser. In particular, a design of experiment (DoE) was developed in order to identify the optimal process parameters to obtain full density, low surface roughness, and high dimensional accuracy. Samples were characterized with Archimedes' method and optical microscopy to determine their final density. It was shown that the first method is fast but not as reliable as the second one. A first mechanical characterization was performed through microhardness tests. Finally, a set of process parameters was identified to produce fully dense samples with low surface roughness and high accuracy. The results showed that the volumetric energy density could represent an approach that is too simplified, therefore limiting the direct correlation with the physical aspects of the process.

Evaluation of a Laboratory-Scale Gas-Atomized AlSi10Mg Powder and a Commercial-Grade Counterpart for Laser Powder Bed Fusion Processing.

Laser powder bed fusion (LPBF) is an additive manufacturing technology that implies using metal powder as a raw material. The powders suitable for this kind of technology must respect some specific characteristics. Controlled gas atomization and post-processing operations can strongly affect the final properties of the powders, and, as a consequence, the characteristics of the bulk components. In fact, a complete characterization of the powders is mandatory to fully determine their properties. Beyond the most used tests, such as the volume particle size distribution (PSD) and flowability, the PSD number, the Hausner ratio and the oxidation level can give additional information otherwise not detectable. The present work concerns the complete characterization of two AlSi10Mg powders: a commercial-grade gas atomized powder and a laboratory-scale gas atomized counterpart. The laboratory-scale gas atomization allows to better manage the amount of the fine particles and the oxidation level. As a consequence, a higher particle packing can be reached with an increase in the final density and tensile strength of the LPBF bulk samples.

Low-Power Laser Powder Bed Fusion Processing of Scalmalloy®.

Among recently developed high-strength and lightweight alloys, the high-performance Scalmalloy® certainly stands out for laser powder bed fusion (LPBF) production. The primary goal of this study was to optimize the Scalmalloy® LPBF process parameters by setting power values suitable for the use of lab-scale machines. Despite that these LPBF machines are commonly characterized by considerably lower maximum power values (around 100 W) compared to industrial-scale machines (up to 480 W), they are widely used when quick setup and short processing time are needed and a limited amount of powder is available. In order to obtain the optimal process parameters, the influence of volumetric energy density (VED) on the sample porosity, microstructure and mechanical properties was accurately studied. The obtained results reveal the stability of the microstructural and mechanical behaviour of the alloy for VEDs higher than 175 Jmm-3. In this way, an energy-and-time-saving choice at low VEDs can be taken for the LPBF production of Scalmalloy®. After identifying the low-power optimized process parameters, the effects of the heat treatment on the microstructural and mechanical properties were investigated. The results prove that low-VED heat-treated samples produced with an LPBF lab-scale machine can achieve outstanding mechanical performance compared with the results of energy-intensive industrial production.

Myopericytoma-like tumors of the lung: Report of two cases.

Myopericytoma is a benign neoplasm presenting cells with different shapes, from oval to spindle, and myoid showing with perivascular growth, which frequently originates from the skin and soft tissues of distal extremities, trunk, head, and neck regions. These tumors rarely have been reported to occur in visceral sites. There is only one case of myopericytoma showing pulmonary involvement with multiple nodules. Although most myopericytomas behave in a benign manner, some cases of malignant myopericytoma arising in both superficial soft tissue and visceral locations have been described. We describe two cases of pulmonary tumors with myopericytoma-like features.

Short Heat Treatments for the F357 Aluminum Alloy Processed by Laser Powder Bed Fusion.

Conventionally processed precipitation hardening aluminum alloys are generally treated with T6 heat treatments which are time-consuming and generally optimized for conventionally processed microstructures. Alternatively, parts produced by laser powder bed fusion (L-PBF) are characterized by unique microstructures made of very fine and metastable phases. These peculiar features require specifically optimized heat treatments. This work evaluates the effects of a short T6 heat treatment on L-PBF AlSi7Mg samples. The samples underwent a solution step of 15 min at 540 °C followed by water quenching and subsequently by an artificial aging at 170 °C for 2-8 h. The heat treated samples were characterized from a microstructural and mechanical point of view and compared with both as-built and direct aging (DA) treated samples. The results show that a 15 min solution treatment at 540 °C allows the dissolution of the very fine phases obtained during the L-PBF process; the subsequent heat treatment at 170 °C for 6 h makes it possible to obtain slightly lower tensile properties compared to those of the standard T6. With respect to the DA samples, higher elongation was achieved. These results show that this heat treatment can be of great benefit for the industry.

Case report: An epidural cavernous hemangioma mimicking a dumbbell-shaped neuroma.

INTRODUCTION AND IMPORTANCE: Spinal epidural cavernous hemangiomas are a rare occurrence. This particular case is made even more distinctive by the fact that the lesion mimicked a dumbbell-shaped neuroma. Moreover, it had a very unique localization (wholly epidural, at cervical-thoracic -C7-D1- level). The importance of this case is linked not only to its remarkable rarity, but also to the diagnostic avenues explored. The surgery was carried out by Prof. Riccardo Caruso, Head of the Neurosurgical Department of the Military Hospital of Rome and Professor of Neurosurgery of Sapienza University of Rome, assisted by Dr. Luigi Marrocco, Senior Neurosurgeon of the Military Hospital of Rome. Postsurgical recovery was managed by Dr. Venceslao Wierzbicki, Senior Neurosurgeon of the Military Hospital of Rome. CASE PRESENTATION: In 2020, a 71 year-old man, suffering from intense pain in the left scapular region and in the ulnar area of the left forearm, underwent surgery for the removal of a spinal epidural cavernous hemangioma involving the left C7-D1 foramen. Prior to surgery, the lesion had been misdiagnosed as a neuroma by a radiologist. CLINICAL DISCUSSION: In the Literature there are other, rare cases of hemangiomas partly located in the spinal canal, and partly located intra and extra foramen. In the case here presented, differential diagnosis as well as a potential Schwannoma, suggested by the dumbbell shape of the lesion, should have considered also the possibility of a meningioma. Two teams of radiologists examined the images, the radiologists of our team, Dr. Valentina Martines and Dr. Emanuele Piccione, thanks to a close inspection of the features of the lesion, postulated the extra-dural position. Other aspects of the scans were then analyzed to help guide future diagnosis of similar lesions. CONCLUSION: With a spinal tumor affecting the foramen, a close examination of the images allows for accurate presurgical differential diagnosis, differentiating between the more frequent neuroma and other rarer tumors, such as a hemangioma.

An Automatic on Top Analysis of Single Scan Tracks to Evaluate the Laser Powder Bed Fusion Building Parameters.

The production of dense samples produced by laser powder bed fusion (LPBF) is mainly determined by the choice of the best combination of construction parameters. Parameter optimization is the first step in the definition of an LPBF process for new alloys or systems. With this goal, much research uses the single scan track (SST) approach for a preliminary parameter screening. This study investigates the definition of a computer-aided method by using an automatic on top analysis for the characterization of SSTs, with the aim of finding ranges of laser power and scan speed values for massive production. An innovative algorithm was implemented to discard non-continuous scans and to measure the SSTs quality using three regularity indexes. Only open source software were used to fine tune this approach. The obtained results on Al4Cu and AlSi10Mg realized with two different commercial systems suggest that it is possible to use this method to easily narrow the process parameter window that allows the production of dense samples.

Effect of Heat Treatment on Microstructure and Selective Corrosion of LPBF-AlSi10Mg by Means of SKPFM and Exo-Electron Emission.

The paper deals with the evolution of the microstructure of AlSi10Mg alloy obtained by laser powder bed fusion (LPBF), as a function of the post-processing heat treatment temperature. This was approached by complementary methods including FE-scanning electron microscopy, scanning Kelvin probe force microscopy and exo-electron emission techniques. The fast cooling rate of the LPBF process as compared to traditional casting produces a very fine microstructure with high mechanical properties and corrosion resistance. However, the LPBF-AlSi10Mg alloy can be susceptible to selective corrosion at the edge of the melt pools generated by the laser scan tracks. Post-process thermal treatments of the Al alloy induce a marked modification of the silicon network at melt pool edges, in particular at high temperature such as 400 °C. It was found that this is associated to a more homogeneous distribution of Volta potential. Analysis of exo-electron emission confirms the silicon diffusion during thermal treatment. The modification of the silicon network structure of the LPBF-AlSi10Mg during thermal treatment reduces the susceptibility to selective corrosion.

Vertebral fractures and mortality risk in hospitalised patients during the COVID-19 pandemic emergency.

BACKGROUND AND OBJECTIVE: Bone fragility has been linked to COVID-19 severity. The objective of this study was to evaluate whether a diagnosis of vertebral fracture (VF) increased mortality risk in COVID-19 patients and whether this effect was greater than in those without COVID-19. METHODS: We assessed VFs by computed tomography (CT) in a cohort of 501 patients consecutively admitted to the emergency department (ED) for clinical suspicion of SARS-CoV-2 infection during the first wave of pandemic emergency. Of those, 239 had a confirmed diagnosis of COVID-19. RESULTS: VF prevalence was similar between COVID-19 and non-COVID-19 groups (22.2 vs. 19%; p = 0.458). Death rates were similar between COVID-19 and non-COVID-19 groups at both 30 (15.8 vs. 12.2%; p = 0.234) and 120 days (21.8 vs. 17.6%; p = 0.236). The mortality risk was higher in COVID-19 patients either with one or multiple fractures compared to those without VFs, at 30 and 120 days, but statistical significance was reached only in those with multiple VFs (30-day HR 3.03, 95% CI 1.36-6.75; 120-day HR 2.91, 95% CI 1.43-5.91). In the non-COVID-19 group, the 30-day mortality risk was significantly higher in patients either with one (HR 7.46, 95% CI 3.12-17.8) or multiple fractures (HR 6.2, 95% CI 2.75-13.98) compared to those without VFs. A similar effect was observed at 120 days. After adjustment for age, sex and bone density, mortality risk remained associated with VFs in the non-COVID-19 group only. CONCLUSIONS: VFs were not independently associated with short-term mortality in patients with COVID-19, but they strongly increased mortality risk in those without COVID-19.

A357 Alloy by LPBF for Industry Applications.

The aim of this study is to define the process parameters to build components for industrial applications in A357 alloy by Laser Powder Bed Fusion (LPBF) and to evaluate the effects of post-processing heat treatments on the microstructure and mechanical properties in order to obtain the highest hardness and strength. First, process parameters values were defined to obtain full dense components with highest productivity. Then samples were built for microstructural, hardness, and tensile strength investigation in different conditions: as-built, after a stress-relieving treatment, and after a T6 precipitation hardening treatment. For this latest treatment, different time and temperatures for solution and ageing were investigated to find the best in terms of final hardness achievable. It is demonstrated that samples in A357 alloy can be successfully fabricated by LPBF with a density of 99.9% and a mean hardness value achievable of 116 HV0.1, in as-built condition. However, for production purposes, it is fundamental to reduce the residual stresses typical of LPBF. It was shown that a similar hardness value could be obtained after a stress-relieving treatment followed by a proper T6 treatment, together with a coarser but more isotropic microstructure.