Michele Boracchi

Technical note: Improvement of cadaveric skin samples (with severe morphological alteration connected to putrefaction or injury) by an extended histological processing

INTRODUCTION The microscopic study and the interpretation of skin samples with advanced post-mortal phenomena or with particular destructive injuries is problematic for the forensic pathologist. In an attempt of restoring the histological architecture of cadaveric skin and overcoming these types of problem, the Authors performed a histological processing that was longer than the standard: it was extended until 62 days to evaluate the improvement of the microscopic morphological aspect. MATERIALS AND METHODS Cutaneous samples were taken from 25 cadavers (5 typologies of skin: charred, putrified, corifed, mummified and partially skeletonized), fixed with a 10%-buffered formalin and then processed in two different ways: one half of the samples was routinely addressed to the standard-time automatic technique, while the other half was manually processed with prolonged times. All the slides were then stained in Hematoxylin-Eosin. RESULTS The standard-processed slides demonstrated marked morphological alterations and artefacts at the microscopic observation; conversely, those processed with the prolonged manual technique showed an improvement in the morphological structure, sometimes permitting the identification of the anatomical components. CONCLUSION Though it is characterized by the inconvenience of protracted times, the application of a long-term manual histological processing to cadaveric skin samples with advanced post-mortal alteration permits to better observe the anatomical architecture of skin and it could be useful and helpful in the evaluation of such cases.

Observations on self-incineration characteristics in 24 years (1993–2016) of autopsies in the city of Milan

Self-incineration is one of the most dramatic and lethal suicide methods. It is rarely reported in Western countries and is more frequent in developing regions. We illustrate the forensic cases of self-immolation occurring over 24 years in the city of Milan, Italy, highlighting the main issues of such a complex and rare suicide. We selected 33 cases of self-incineration among 23,417 autopsies (4022 suicides) performed at the Department of Legal Medicine of the University of Milan over a period of 24 years (1993–2016). Several parameters were included and analysed: gender and age of the victims, pathological history, previous suicide intentions/attempts, duration of burning, place of death or discovery of the corpse, circumstantial data of fatal events and autopsy findings, with particular attention to thermal injuries. Self-incineration was found in 0.8% of total suicides and 0.14% of total autopsies. One of these cases involved a complex modality (association with plastic-bag suffocation). The typical characteristics of the victim were an Italian man with psychiatric illness, frequently moved by passion, existential discomfort and economic problems. During the 24-year period, the number of cases of self-incineration progressively reduced. This study provides a general overview in one of the biggest metropolitan Italian areas and is one of the few works performed on this topic. It may be helpful in understanding and studying such an unusual manner of suicide.

Technical note: A histochemical approach in diagnosing hanging mechanical asphyxia on cadavers undergoing advanced putrefactive phenomena

The authors used a particular protocol on putrefied corpses to highlight the cutaneous furrow. Two groups of cadavers were selected: in the first group (suicide by hanging mechanical asphyxia), the authors sampled cutaneous lozenges on the furrow still macroscopically recognisable, while in the second group (corpses deceased by different means), we sampled cutaneous lozenges in the hypostatic leaning. All specimens were divided in two: one underwent standard fixation while the other, previously rehydrated in Sandison’s solution, was then fixed in formalin. All specimens were stained with hematoxylin and eosin and Resorcin-Fuchsin. Samples processed with formalin and the H&E staining underlined various artifacts; vice versa, the Sandison solution associated with Resorcin-Fuchsin staining demonstrated the compression of the elastic fibres, with focal positivity in hanged corpses, and diffuse positivity in the entire hypostatic leaning. Sandison’s rehydrating solution and Resorcin-Fuchsin staining exalt the supposed application of an asphyctic mean even on putrefied corpses in those cases burdened by a diagnostic doubt.

Can cadaverous pollution from environmental lead misguide to false positive results in the histochemical determination of Gunshot Residues? In-depth study using ultra-sensitive ICP-MS analysis on cadaveric skin samples

INTRODUCTION In a previous work, we wanted to evaluate if the histochemical determination of lead in Gunshot Residues (GSR) on firearm wounds could be misled due to possible environmental contamination produced by heavy metals and, in particular, by lead. The Sodium Rhodizonate test and its confirmation test with 5% HCl Sodium Rhodizonate resulted to be negative and therefore we wanted to verify if these techniques were sensible enough in order to evaluate this element. We have assessed, on these same samples, a more sensitive technique, as inductive coupled plasma mass spectrometry (ICP-MS) is. This technique is able to detect elements in solution at concentrations as low as 10-15gL-1. MATERIALS AND METHODS Skin samples taken from two groups of victims, whose cause of death was not related to gunshot wounds were analyzed using ICP-MS: group A included 25 corpses found in open spaces after a long time; group B included 16 corpses exhumed after a period of 11 years. As a positive control group we used skin samples from two subjects that had died due to firearm wounds: as a negative control group we used three different types of plain paraffin slides without included biological material. RESULTS At the analysis by ICP-MS, the evaluation of the samples belonging to groups A, B and for the negative control groups resulted to be negative for traces of lead (Pb), barium (Ba) and antimony (Sb). On the other hand, high concentrations of GSR could be found in the positive control group were victims died for firearm wounds. CONCLUSIONS On these basis, we can state that environmental Pb does not contaminate cadavers exposed to open air nor those buried in soil, as confirmed using to ICP-MS technique. Sodium Rhodizonate and 5% HCl Sodium Rhodizonate confirmation test have therefore a high sensitivity, highlighting GSRs, for the diagnosis of death caused by firearm wounds.

Lethal cardiac amyloidosis: Modification of the Congo Red technique on a forensic case

Congo Red staining is usually used in diagnosing amyloidosis, a pathology characterized by the storage of abnormal proteins in several human organs. When assessed on samples fixated in formalin and embended in paraffin, this staining can undergo several artefacts, causing diagnostic and interpretative difficulties due to its weak stainability and a consequent reduced visibility of the amyloid. These complications, in time, requested several variations of this staining technique, especially in clinical practice, while in the forensic field no protocols has ever been adapted to cadaveric samples, a material that is already characteristically burdened by a peculiar stainability. In our work, studying a sudden death caused by cardiac amyloidosis and diagnosed only with post-mortem exams, we present a modified Congo Red staining used with the purpose to demonstrate amyloid in cadaveric material after the unsuccessfully use of all standard protocols.

The detection of metallic residues in skin stab wounds by means of SEM-EDS: A pilot study

The morphological analysis of stab wounds may often not be accurate enough to link it with the type of wounding weapon, but a further evaluation may be performed with the search for metallic residues left during the contact between the instrument and the skin. In this study, Scanning Electron Microscopy-Energy Dispersive Spectroscopy (SEM-EDS) was applied to the study of cadaveric stab wounds performed with kitchen knives composed of iron, chromium and nickel, in order to verify the presence of metallic residues on the wounds edge. Two groups of 10 corpses were selected: group A, including victims of stab wounds and a control group B (died of natural causes). Samplings were performed on the lesions and in intact areas of group A, whereas in group B sampling were performed in non-exposed intact skin. Samples were then analysed with optical microscopy and SEM-EDS. In group A, optical microscopic analysis showed the presence of vital haemorrhagic infiltration, while SEM-EDS showed evidence of microscopic metal traces, isolated or clustered, consisting of iron, chromium and nickel. Moreover, in two cases organic residues of calcium and phosphate were detected, as a probable sign of bone lesion. Control samples (group A in intact areas and group B), were negative for the search of exogenous material to optical microscopy and SEM-EDS. The results show the utility and possible application of the SEM-EDS in theidentification of metallic residues from sharp weapons on the skin.

A particularly complex case of matricide by means of plastic bag suffocation: Case report:

A rare case of homicide with plastic bag suffocation is presented in which forensic genetic investigations were carried out on the inner surface of a plastic bag placed over the head of an elderly woman, bedridden after a stroke. The results obtained suggested that she had been murdered and hinted at the perpetrator of the crime. In fact, it emerged that biological traces left by the victim matched those of her principal caregiver, her psychotic daughter, who later confessed to the crime. The old woman also had a son affected by a serious illness, whose genetic profile was found on the same bag. In a later interview, he stated that his sister had tried to kill him too, thus confirming the genetic findings and allowing the investigators to hypothesise that the daughter had used the same means to try to kill him. Based on these results, the usefulness of forensic genetic testing when investigating complex plastic bag suffocation deaths is highlighted. This peculiar case deserves interest, since no murder of this kind has ever been reported in the Italian forensic literature.

Sudden perinatal death due to rupture of congenital cardiac diverticulum. Pathological findings and medico-legal investigations in malpractice charge

Congenital diverticula of the left ventricle, very rare malformations, are determined by an abnormal embryonic development of the ventricular wall and can be isolated or associated to other cardiac anomalies. In most of the cases, these pathologies are not symptomatic and in some patients can be associated to ventricular arrhythmia, cardiac rupture with tamponade and sudden death. Authors are presenting the case of a sudden death in an 8-weeks-old newborn due to rupture of a cardiac congenital diverticulum of the left ventricle, discovered only at the moment of the autopsic examination. The parents of the victim pressed charges against the medical staff that was appointed to the cares, blaming them with malpractice. The missed diagnosis of a cardiac congenital diverticulum of the left ventricle, a rare pathology, reflects the trickiness of the medical management that can lead to medico-legal controversies and, even though such rare conditions must be always taken into consideration when investigating possible dysfunction causing the death, diagnostic difficulties, in the case in exam, justify the missed diagnosis intra-vitam of cardiac ventricular diverticulum.

Can cadaverous pollution from environmental lead misguide to false positive results in the histochemical determination of gunshot residues? Study on cadaveric skin samples

Histochemical determination of lead in gunshot residues (GSR) raises the question of possible environmental contamination by heavy metals. Authors assess the specificity of the Sodium Rhodizonate Test in the search of lead derived from environmental pollution. Sodium Rhodizonate Test and 5% HCl Sodium Rhodizonate test were applied to skin samples taken from two groups of victims, whose cause of death was not related to gunshot wounds: group A included 25 corpses found in open spaces after a long time; group B included 16 corpses exhumed after a period of 11 years. The use of these histochemical tests to skin samples from these two groups did not show metal debris histochemically similar to the lead present in GSR. These tests were confirmed to be specific in highlighting the GSR coming from gunshot, without being affected by the potential environmental contamination of the heavy metal pollutants, coming from air or soil.