Visonà S D, Chen Y, Bernardi P, Andrello L, Osculati A
Department of Public Health, Experimental and Forensic Medicine, University of Pavia, Via Forlanini 12, 27100 Pavia, Italy.
Department of Public Health, Experimental and Forensic Medicine, University of Pavia, Via Forlanini 12, 27100 Pavia, Italy.
Forensic Sci Int. 2018 Mar;284:107-116. doi: 10.1016/j.forsciint.2018.01.001. Epub 2018 Jan 10.
Deaths from electricity, generally, do not have specific findings at the autopsy. The diagnosis is commonly based on the circumstances of the death and the morphologic findings, above all the current mark. Yet, the skin injury due to an electrocution and other kinds of thermal injuries often cannot be differentiated with certainty. Therefore, there is a great interest in finding specific markers of electrocution. The search for the metallization of the skin through Scanning Electron Microscope equipped with Energy Dispersive X-Ray Spectroscopy (EDS) probe is of special importance in order to achieve a definite diagnosis in case of suspected electrocution.
We selected five cases in which the electrocution was extremely likely considering the circumstances of the death. In each case a forensic autopsy was performed. Then, the skin specimens were stained with Hematoxylin Eosin and Perls. On the other hand, the skin lesions were examined with a scanning electron microscope equipped with EDS probe in order to evaluate the morphological ultrastructural features and the presence of deposits on the surface of the skin.
The typical skin injury of the electrocution (current mark) were macroscopically detected in all of the cases. The microscopic examination of the skin lesions revealed the typical spherical vacuoles in the horny layer and, in the epidermis, the elongation of the cell nuclei as well as necrosis. Perls staining was negative in 4 out 6 cases. Ultrastructural morphology revealed the evident vacuolization of the horny layer, elongation of epidermic cells, coagulation of the elastic fibers.
EDS-MICROANALYSIS: In the specimens collected from the site of contact with the conductor of case 1 and 2, the presence of the Kα peaks of iron was detected. In the corresponding specimens taken from cases 2, 4, 5 the microanalysis showed the Kα peaks of titanium. In case 3, titanium and carbon were found.
In the suspicion of electrocution, the integrated use of different tools is recommended, including macroscopic observation, H&E staining, iron-specific staining, scanning electron microscopy and EDS microanalysis. Only the careful interpretation of the results provided by all these methods can allow the pathologist to correctly identify the cause of the death. Particularly, the present study suggests that the microanalysis (SEM-EDS) represents a very useful tool for the diagnosis of electrocution, allowing the detection and the identification of the metals embedded in the skin and their evaluation in the context of the ultrastructural morphology.
一般来说，电击死亡在尸检时没有特异性发现。诊断通常基于死亡情况和形态学发现，尤其是电流斑。然而，电击所致的皮肤损伤与其他类型的热损伤往往难以明确区分。因此，寻找电击的特异性标志物备受关注。通过配备能谱仪（EDS）探头的扫描电子显微镜来探寻皮肤金属化，对于疑似电击案件做出明确诊断尤为重要。
我们选择了五例根据死亡情况极有可能是电击致死的案例。对每例均进行法医尸检。然后，皮肤标本进行苏木精-伊红染色和普鲁士蓝染色。另一方面，用配备EDS探头的扫描电子显微镜检查皮肤损伤，以评估形态学超微结构特征及皮肤表面沉积物的存在情况。
所有案例均在宏观上检测到典型的电击皮肤损伤（电流斑）。皮肤损伤的显微镜检查显示角质层有典型的球形空泡，表皮细胞核拉长以及坏死。6例中有4例普鲁士蓝染色呈阴性。超微结构形态显示角质层明显空泡化，表皮细胞拉长，弹性纤维凝固。
在病例1和2与导体接触部位采集的标本中，检测到铁的Kα峰。在病例2、4、5相应部位采集的标本中，微分析显示有钛的Kα峰。在病例3中，发现了钛和碳。
对于疑似电击案件，建议综合使用不同方法，包括宏观观察、苏木精-伊红染色、铁特异性染色、扫描电子显微镜检查和能谱微分析。只有仔细解读所有这些方法提供的结果，病理学家才能正确确定死因。特别是，本研究表明微分析（扫描电镜-能谱仪）是诊断电击的非常有用的工具，能够检测和识别嵌入皮肤的金属，并在超微结构形态背景下对其进行评估。
