Spontaneous acute epidural hematoma secondary to skull and dural metastasis of hepatocellular carcinoma: A case report

BACKGROUND The skull and dura are uncommon sites for the metastasis of hepatocellular carcinoma(HCC).Spontaneous acute epidural hematoma(AEDH)is also very rare.We report here a spontaneous AEDH secondary to skull and dural metastasis of HCC.This case is extremely rare.CASE SUMMARY A 48-year-old male patient with a history of HCC developed unconsciousness spontaneously.Head computed tomography showed"a huge AEDH in the left parietal and occipital region with osteolytic destruction of the left parietal bone.Emergent operation was performed to evacuate the hematoma and resect the lesion.Pathological study revealed that the lesion was the metastases from HCC.The patient died of lung infection,anemia,and liver failure 3 wk after operation.CONCLUSION Spontaneous AEDH caused by hepatocellular carcinoma(HCC)dural and skull metastases is extremely rare,the outcome is poor.So,early diagnosis is important.If the level of AFP does not decrease with the shrinkage of intrahepatic lesions after treatment,it is necessary to be alert to the existence of extrahepatic metastases.Since most of the patients had scalp and bone masses,physicians should pay attention to the patient's head palpation.Once a patient with the history of HCC had sudden neurological dysfunction,the possibility of spontaneous AEDH caused by the skull and dura mater metastases should be considered.Since hemorrhage is common in the skull HCC metastases,for patients with spontaneous AEDH accompanied by skull osteolytic lesions,it is also necessary to be alert to the possibility of HCC.For AEDH secondary to HCC metastases,early diagnosis and timely treatment are critical to improve the patients’outcomes.

Microstructure and property of laser additive manufactured alloy Ti-6Al-2V-1.5Mo-0.5Zr-0.3Si after aged at different temperatures

The solid solution and aging treatment for conventional manufacturing processes might not be suitable for laser additive manufactured titanium alloys due to the different lamellar microstructures.In this study,the influence of aging temperatures(600,700 and 800°C)on microstructure and mechanical properties of titanium alloy Ti-6Al-2V-1.5Mo-0.5Zr-0.3Si was investigated.The results indicate that after solid solution treatment at 970°C followed by water quenching,the alloy mainly consists of coarsening lamellar a phase in martensite α' matrix.Aging at 600°C will not change the size of primary lamellar α phase but lead to huge amount of secondary a phases(α_(s))generating with very fine microstructure.By increasing the aging temperature,the number of α_(s) decreases but with coarsened microstructures.When aged at 800°C,the width of the asphase reaches 350 nm,almost 7 times wider than that aged at 600°C.The changing size of α_(s) obviously influences the property of the alloy.The fine α_(s) leads to high strength and microhardness but low plasticity,and specimen aged at 700°C with suitable assize has the best comprehensive properties.

Effects of annealing temperature and cooling rate on microstructures of a novel titanium alloy Ti-6Al-2V-1.5Mo-0.5Zr-0.3Si manufactured by laser additive manufacturing

The microstructure changes of Ti-6Al-2V-1.5Mo-0.5Zr-0.3Si alloy manufactured by laser additive manufacturing （LAM） are systematically investigated with statistical analysis of primary α phase （αp） and secondary α phase （αs） under different annealing conditions. Results indicate that, with the increase in holding temperature, the content of αp lamellas decreases with the increasing αs content, maintaining the total α phases concentration stabilized. The width of αp lamellas and the nominal specific surface area of α phase both exhibit positive correlation with the temperature, while the increment of αp and the widths of αs lamellas show an increase-decrease tendency. Besides, with the decrease in cooling rate, the total content of α and the width of αp lamellas increase, while the nominal specific surface area of α phase shows no significant change. The results indicate that, in the annealing process, the holding temperature determines the surplus and growth interfaces of % lamellas, and the cooling rate influences the nucleation quantity of c^s in unit time. During the cooling stage, the αp lamellas grow initially, and then, the nucleation and crab-like structure growth occur followed by those of the αs lamellas. The time intervals among them are influenced by cooling rate. The mechanism of microstructure formation of the LAMed titanium alloy during annealing stage was discussed, which would guide for the heat treatment method to achieve required microstructure.

Microstructure and properties of hybrid additive manufacturing 316L component by directed energy deposition and laser remelting

Arc additive manufacturing is a high-productivity and low-cost technology for directly fabricating fully dense metallic components.However,this technology with high deposit rate would cause degradation of dimensional accuracy and surface quality of the metallic component.A novel hybrid additive manufacturing technology by combining the benefit of directed energy deposition and laser remelting is developed.This hybrid technology is successfully utilized to fabricate 316L component with excellent surface quality.Results show that laser remelting can largely increase the amount ofδphases and eliminateσphases in additive manufacturing 316L component surface due to the rapid cooling.This leads to the formation of remelting layer with higher microhardness and excellent corrosion resistance when compared to the steel made by directed energy deposition only.Increasing laser remelting power can improve surface quality as well as corrosion resistance,but degrade microhardness of remelting layer owing to the decrease inδphases.

Improvement of proof-ultimate strength difference in laser additive manufactured Ti-6Al-2V-1.5Mo-0.5Zr-0.3Si alloy by tuning basketweave structure

After annealed at 1000 ℃, a special basket-weave structure is obtained in laser additive manufactured Ti-6Al-2V-1.5Mo- 0.5Zr-0.3Si alloy. The unit of the special basket-weave structure is a lamellas clusters, which consist of lamellar primary ot (otp), crab-like structures at the edges of otp and lamellar secondary a (as) on both sides of otp. As the units of basket-weave structures, the width of the clusters is much larger than that of a lamellas in as-deposited alloy. The formation temperature and process of the special basket-weave structure are studied, and the room temperature properties are tested and compared with the as-deposited alloy. The results show that the formation of the special basket-weave structure finishes within about 30 s and crab-like structures form earlier than lamellar as. The yield strength of the alloy is decreased by about 75 MPa compared to that of the as-deposited alloy. Besides, the proof-ultimate strength difference of the alloy is two times higher than that of the as-deposited alloy with about 34% improvement for the impact toughness. It is because ot colony size shows a positive correlation to the width of the unit forming basket-weave structure. The enhancement in proof-ultimate strengthdifference could significantly improve the toughness of the alloy, and thus effectively increase the safety of the alloy.