The role of routine histology in the determination of cause of death in medico-legal autopsies
Medical autopsies are performed to establish a cause of death, determine the extent of a disease or to evaluate given therapy. This differs from the purpose of a medico-legal autopsy, which is performed when deemed necessary by the police, as a part of an ongoing death investigation. The purpose of the medico-legal examination is. i.a., to determine cause and manner of death.
The value of a standard histological examination, rather than a case-specific judgement of the need of histological examination, is debated within the forensic community. In a study of 189 autopsies, histological examination changed the cause of death in less than 1% of the cases (Molina et al 2007), concluding that if the cause and manner of death is evident from the circumstances and the macroscopic examination, there is no need to perform a histological analysis. Similar results were found in a study of 100 suicidal hanging deaths (Tse et al 2012). A third study indicated that in 8%, histological examination contributed to the determination of the cause of death (Fronczek et al 2014).
In only one of these studies (Tse et al 2012), the study population did not constitute a mix of causes of death. Since it is obvious that the value of histological examination varies between different causes of death, the aim of this study is to give a better understanding of the role of histology by separately studying different causes of death - e.g., unnatural deaths such as motor vehicle crashes and fire related deaths, and various groups of natural deaths.
A retrospective study will be conducted of 100 randomly selected cases in each group of cause of death, e.g. unnatural causes such as high energy trauma deaths and fire-related deaths, as well as in various natural causes. Study cases will be collected from the database of the National Board of Forensic Medicine where a medico-legal autopsy was performed, including external and internal examination, toxicologal analyses and a routine histological analysis of samples from heart, liver, lungs, kidneys and in some cases also other inner organs.
Firstly, selected forensic pathologists will be sent the autopsy report, without the histological analysis. They will assess and present the (probable) cause and manner of death (i). Secondly, they will gain access to the histological analysis and subsequently make a second assessment (ii). We will then analyze if the histological analysis has contributed to or altered the primary (i) cause or manner of death.
If the study concludes that histological analyses in certain cause-of-death groups do not contribute to the determination of cause or manner of death, the value of doing such examinations on a standard basis can be questioned. It is not only a matter of using resources efficiently, but there are also ethical and judicial aspects to consider. The Swedish Autopsy Act states that organic material can be retained only if it is necessary to fulfill the purpose of the autopsy.