- Email: [email protected]
PATHOLOGY | Autopsy
PATHOLOGY/Autopsy
part provided through major institutes of forensic science, and a number of these exist in association with institutes of forensic medicine and pathology. Given the concentration upon basic biological principles in undergraduate medical training, it is not surprising that a forensic pathologist often has the necessary expertise to take part in forensic biological service work and to give expert evidence in the field of forensic biology. Today, the forensic application of developments in molecular biology involving the analysis and comparison of DNA has been one of the great success stories of forensic biology. Forensic pathologists are often well equipped to analyze and comment on the general use of these techniques. Forensic toxicologist
Medical pharmacology and therapeutics form part of the basic education of all legally qualified medical practitioners. Knowledge of drugs and their normal and abnormal effects on the human body are fundamental to medical practice. While most doctors understand the toxic effects of therapeutic and some nontherapeutic drugs, details regarding the wide range of substances that are dangerous to the human body exceed the knowledge of most doctors. It is scientists specializing in forensic toxicology who screen and analyze human tissues for drugs and toxins. Forensic pathologists have a specific interest in this area. This is because the forensic pathologist has to determine issues relating to the cause of death and circumstances of death of individuals. Where such deaths are apparently the result of toxic substances, then a forensic pathologist must collect the appropriate body samples and, together with a forensic toxicologist, arrange for the most appropriate analysis. Medical detective
Forensic pathologists, more than all other specialists in medical practice, are medical detectives. They are involved in all phases of a death investigation and form part of the detection team that analyses the circumstances of a death. This role of medical detective is often glorified in the media, where the forensic pathologist is frequently elevated to the key player in the investigation. In reality the forensic pathologist participates on an equal basis with all other specialist investigators in the team investigating a death. Forensic pathologists provide far more than an autopsy service for the justice system. Their unique range of skills and expertise overlaps many of the traditional scientific, medical and legal compartments, and as such can be a highly effective and efficient resource for investigators.
1155
See also: Education: An International Perspective. Toxicology: Overview. Legal Aspects of Forensic Science:
Further Reading Brodrick Committee Report (1971) Cmnd. 4810 Report of the Committee on Death Certification and Coroners. London: Home Office. Gonzalez-Crussi F (1987) Three Forms of Sudden Death: and Other Reflections on the Grandeur and Misery of the Body. London: Picador. Hill RB and Anderson RE (1988) The Autopsy: Medical Practice and Public Policy. Boston: Butterworth. Knight B (1991) Forensic Pathology. London: Edward Arnold. Plueckhahn VD and Cordner SM (1991) Ethics, Legal Medicine and Forensic Pathology, 2nd edn. Melbourne: Melbourne University Press. Selby H The Aftermath of Death: Coronials. Leichhardt, NSW: Federation Press. Spitz WU and Fisher RS (1993) Spitz and Fisher's Medicolegal Investigation of Death: Guidelines for the Application of Pathology to Crime Investigation. Springfield, IL: Thomas.
Autopsy D J Pounder, University of Dundee, Dundee, UK Copyright # 2000 Academic Press doi:10.1006/rwfs.2000.0584
Introduction The autopsy, or necropsy as it is sometimes known in Britain, is a postmortem dissection of the body. The literal meaning of autopsy is `to see for oneself'. Autopsies are of two types: those performed in a hospital setting for purely medical purposes, and those performed under legal authority for forensic purposes. The `hospital' autopsy and the forensic autopsy address different questions and have different approaches. These differences are reflected in the conduct of the examination, the ancillary investigations, the significance attached to physical evidence, the approach to documentation, and the requirement for chains of custody. The `hospital' autopsy focuses on the internal examination of the body and the correlation of the findings with the clinical record. The broad purpose of the medicolegal autopsy is to gather evidence relevant to the investigation of a
1156 PATHOLOGY/Autopsy
death by legal authorities. The medicolegal autopsy has the purpose of establishing a cause of death; assisting in interpreting and correlating the facts and circumstances surrounding the death; recovering and preserving evidence; reconstructing how injuries occurred; establishing the identity of the deceased; estimating the time since death; providing an accurately observed record of the medical findings; and assisting in addressing the medicolegal aspects of public safety, public health and criminal and civil court proceedings.
Autopsy Strategy A medicolegal death investigation is much broader than the autopsy, and includes the scene of death examination and the gathering of witness and documentary evidence. The latter includes the social, psychiatric and medical history of the deceased. This background information informs and directs the conduct of the forensic autopsy. Every autopsy begins with a review of the available investigative information, an evaluation of the medicolegal issues arising, and the development of a strategy for the conduct of the autopsy. This strategy draws upon a repertoire of techniques, and structures the conduct of the postmortem examination to obtain the maximum amount of evidence relevant to the specific issues of the case. Such a strategy is inevitably flexible, as the ongoing examination may bring new information to light. Identification
Who, when, where, why, how and what are the questions that the autopsy assists in answering. Who has died is not usually at issue, but establishing identity can be a problem in some instances. There may be no circumstantial evidence of the identity of a person found dead, or visual identification may be impossible because of decomposition, fire damage, physical disruption or mutilation. In all of these circumstances special techniques will be required and then identification becomes a multidisciplinary effort. Radiology, dentistry, anthropology, law enforcement, criminalistics and molecular biology may be involved. The commonest methods of scientific individualization are fingerprints, dentistry and radiography. DNA analysis is increasingly used. The essential principle of individualized identification is to make a match between a unique feature, physically part of the body, and an antemortem record of that unique feature. This requires an accurate and reliable antemortem record. In exceptional circumstances it may be necessary to resort to the less robust methods of photographic superimposition and facial reconstruction.
Time and place of death
When the person died is usually best established from the circumstantial evidence, and is not commonly an important issue. However, it may be critical when alibi is the defence in a homicide, or when the sequence of deaths of family members killed in the same incident influences the inheritance of estates, or when life insurance policies have lapsed in the time between the disappearance of a person and the discovery of the body. Again, special techniques need to be applied to establish the time since death. Where the person died is usually where the body was found, but not always. Homicide victims may be dumped, and bodies may travel long distances in rivers and the sea prior to their recovery. The autopsy may provide evidence that the body has been moved after death, as well as trace evidence originating from the place of death. Cause of death
Establishing why the person died ± that is, the disease or injury initiating the sequence of events, short or prolonged, leading to death ± is one of the most important functions of the autopsy. However, the cause of death may be readily apparent from the circumstances and the condition of the body, such as a passenger in an air crash, and in these cases the autopsy is required for other investigative reasons, such as victim identification and accident reconstruction. There are many causes of death, both natural and unnatural, that cannot be established with certainty by autopsy alone. Examples include epilepsy, asthma and drowning. In such deaths the autopsy assists by excluding other potential causes of death from trauma, drugs or natural disease. In a forensic autopsy, the demonstration of the absence of injury or disease may be as important as the demonstration of unequivocal or occult injury. Some natural diseases, particularly coronary artery disease, are chronic and can kill at any time, so their identification at autopsy represents a potential cause of death but not necessarily the cause of death. Similarly, drugs such as alcohol, morphine and other opiates, to which individuals develop tolerance, may be found at autopsy in concentrations in blood sufficient to account for death but not necessarily lethal. Very minor injuries may be consistent with a subtle form of homicidal trauma, such as soft smothering, and sufficient to arouse suspicion but not provide conclusive proof. Only in a minority of deaths are there autopsy findings of a trauma, poisoning or natural disease incompatible with life, so that the cause of death is established with certainty by the autopsy alone. For the great majority of death investigations, establishing why the person died requires the integrated analysis of the autopsy findings and
PATHOLOGY/Autopsy
scene of death and anamnestic data. In a small number of deaths a thorough investigation, including an autopsy, may fail to establish the cause of death. Such a case is characterized as a `negative autopsy' in the English-speaking world and as a `white autopsy' in the Spanish-speaking world. Manner of death
How the person died ± that is, the manner of death ± is a single word description of the circumstances leading up to the death. The manner of death may be natural or unnatural, and if unnatural may be accidental, suicidal or homicidal. Deaths from alcohol and drug abuse are difficult to classify and in some jurisdictions are simply described as `unclassified'. For some deaths the manner may be undetermined, either because the cause of death is unknown or because the circumstances are unclear; for example, whether a drowning was accidental or suicidal. Responsibility for determining the manner of death always lies with the legal authority, but this may be the autopsy pathologist if the jurisdiction has a North American-style medical examiner system. Surrounding circumstances
Establishing what happened to the deceased ± that is, the totality of the events leading up to and surrounding the death ± is invariably the focus of any legal proceedings. The autopsy can assist in this by establishing objective evidence of some of the things that happened or, more commonly, evidence limiting what could have happened. In homicide investigations, the autopsy can provide information on victim position, weapon used, sequence of injuries, postinjury activities, period of consciousness, survival time, time of death, postmortem interference with the body and method of disposal.
Legal Authority The law, regulations and local administrative practices governing medicolegal autopsies vary from place to place. Wherever the jurisdiction, before the start of any autopsy there must be legal authority to proceed. Only the appropriate law officer can provide this authority, and he or she may be a judge, prosecutor, coroner or medical examiner. The consent of the next of kin is not required, and in most instances they have no effective means of objecting. However, ethnic and religious minorities who have principled objections to postmortem dissections have achieved the legal right of objection in some jurisdictions. The pathologist receiving the authority for autopsy should permanently record how it was received, from whom and
1157
when. The autopsy report will ultimately need an introductory statement of the legal authority upon which it was performed. The next requirement is a formal identification of the decedent by a method meeting the necessary legal requirements. In a case in which no court proceedings are anticipated, simply noting the details contained on the mortuary body tag and any accompanying documentation may suffice. In other circumstances visual identification of the decedent by next of kin, possibly in the presence of a pathologist, or the use of a scientific method may be required. Whatever method is used, it should be formally recorded in the autopsy report.
External Examination The medicolegal autopsy requires the accurate observation and accurate documentation of both the external and the internal examination findings. The external examination is an essential component of the postmortem examination and constitutes the first part of the forensic autopsy. In some deaths it may be appropriate to limit the postmortem examination to the external examination without internal dissection. This is a judgment to be made by the pathologist and law officer in light of the legal requirements, public health concerns, potential for criminal prosecution or civil litigation, resource constraints, and the religious and personal views of the next of kin. The external examination embraces everything on and upon the body, including clothing, physical evidence and medical paraphernalia. Clothing
Examination of the undisturbed clothing is a valuable part of the autopsy. In some jurisdictions the body is stripped naked by police officers or mortuary technicians before presentation to the pathologist, but this is an unwise practice. The clothing can provide a wealth of useful information on the lifestyle of the decedent, events surrounding the death and the cause of death. If the pathologist does not document the clothing then it is often not documented at all. Each article of clothing should be described in appropriate detail and, when the body is unidentified, details of the labels and laundry marks as well. Description of the clothing should include general descriptions of any disarrangement, damage and stains. Recovery of trace evidence from clothing may be undertaken either at the scene of death or in the autopsy room, depending upon local practice and the nature of the case. Trace evidence might include hairs, fibers, paint chips, glass fragments, vegetation and insects. The collection and storage of this trace evidence must meet the legal
1158 PATHOLOGY/Autopsy
requirements for the chain of custody. The appropriateness of the clothing should be assessed against the scene of death and anamnestic information, particularly in potential hypothermic deaths. Stains, scuffmarks and tears to clothing may assist in traffic accident reconstruction or in clarifying events surrounding a death. Gunshot holes and stab wounds to clothing provide useful information in themselves, but more so when correlated with the underlying injuries to the body. Bloodstain patterns to clothing may illuminate the events following trauma and the activities of the victim prior to collapse. Jewelry may provide evidence of identification; medical bracelets and necklaces may indicate a chronic disease; pockets may contain medication or drugs of abuse; and personal papers may give information on identity, medical history and lifestyle. Stains
Before removing clothing and personal effects, and cleaning the body of any stains, it may be necessary to make a permanent photographic record, particularly in a case of homicide. After removal of the clothing, a head-to-toe detailed examination of the naked body is made. In the first instance this external examination should document stains and soiling, general and specific identifying characteristics, evidence of medical intervention and postmortem changes. Stains to the exposed body surfaces may be described at the time of the examination of the clothing and supplemented with a description of stains to the whole body. The location, extent and type of staining or soiling can provide useful information. Blood flow patterns from wounds reflect body position after wounding; highvelocity impact blood splatter and gunshot residue stains on the hands may indicate suicide; `coffee grounds vomitus' around the mouth and melena staining of the buttocks suggest death from massive gastrointestinal hemorrhage; vomitus containing tablet debris raises the possibility of suicidal overdose. General descriptors
The general external description should include height, weight, build, sex, race, head and body hair, eyes, dentition, scars, tattoos and body piercings and evidence of natural disease, particularly ankle edema and varicose veins, which raise the possibility of a cardiovascular death. The back, anus and perineum, palms and soles must always be examined. A specific search for petechial hemorrhages in the eyelids, conjunctivae, inner lips, face and neck is mandatory because they are easily overlooked but of considerable importance in the diagnosis of asphyxia. The recording of postmortem changes to the body
does not usually include body temperature unless there is a specific concern about the time of death. Core body temperature obtained rectally, or by a liver stab, is required. The presence or absence, and the pattern, of postmortem lividity, rigor mortis and putrefaction are routinely observed and recorded. Postmortem lividity (livor mortis or hypostasis) reflects gravitational pooling of blood after death, and thus body position. Areas of contact pallor produced by pressure from clothing or adjacent objects should correlate with the scene of death findings. A pink lividity, rather than the usual purple-red, raises the possibility of death from carbon monoxide poisoning, cyanide or hypothermia. Rigor mortis, which develops some hours after death, fixes the body in the position in which it came to rest and should also correlate with the scene of death findings. Neither lividity nor rigor is of any substantial value in estimating time of death. Postmortem injuries produced during the recovery of the body or by the feeding of insects, birds, animals or crustaceans are recorded separately from injuries produced in life in order to avoid confusion. Medical intervention
In many deaths there is evidence of attempts at lifesaving medical intervention. Where disposable medical equipment is attached to the body this should not be removed at the scene of death but transported with the body to the mortuary to be recorded by the pathologist. The most common items are airways and solutions for intravenous infusion. All of these require description and an assessment of their correct placement, together with recording of any associated bleeding, bruising or other tissue damage. Emergency medical treatment is rarely documented in detail at the time it is given because of the urgency of the circumstances, and consequently the autopsy record is often the most complete and reliable record. It may be important in any civil litigation for malpractice. Injuries produced by medical intervention, particularly those in the neck, may be misinterpreted as assaultive if not viewed in context. Recording intravenous lines eliminates the possibility that the associated needle puncture marks may give rise to a false suspicion of intravenous drug abuse. Injuries
The final stage of the external examination is the documentation of injuries. These are described systematically, either by grouping them according to injury type and anatomical location, or by numbering them, without implying an order of infliction or ranking of severity. Each injury is characterized by its type
PATHOLOGY/Autopsy
± for example, bruise, abrasion, laceration, incised wound, stab wound, gunshot wound, burn ± and its general anatomical location. The precise anatomical site of an injury is recorded in cases of homicide or if it is of particular significance for the reconstruction of the circumstances ± for example, a single suicidal gunshot wound or an imprint injury from a vehicle striking a pedestrian. Precisely locating a wound is analogous to giving a latitude and longitude with respect to fixed landmarks, which may be the midline of the chest, the heel or top of the head, or any fixed bony prominence. The size, shape and other relevant features of the injury, depending on its type, are observed and recorded. For this purpose photography is of special value in documenting a wealth of detail. The individual external injuries are described in continuity with any associated internal injuries in the final autopsy report. However, of necessity, the practicalities of the dissection of the body may require that this is carried out in a somewhat disjointed fashion, particularly where there are a large number of wounds. All penetrating wounds, such as gunshot wounds and stab wounds, must be traced from their entry point through the body to their termination or exit point. All nonpenetrating injuries need to be associated with damage to the underlying tissues such as bony fractures, lacerated blood vessels and associated hemorrhage. Special procedures
Special procedures utilized during the external examination include photography for the purposes of identification and documentation. Infrared and ultraviolet photography will enhance tattoos, bruises and patterned injuries. High-contrast black-and-white photography or computer-directed image enhancement can be used to enhance patterned injuries. Trace material can be identified with ultraviolet, laser or alternative light sources. Fingerprinting may be required for identification purposes, and is routine for all homicide victims. Where sexual assault is suspected, the collection of physical evidence includes what would normally be collected in a living victim. Insect specimens, such as fly maggots, may be useful for estimating time of death or for toxicological studies. Gunshot residues can be collected from the skin surface. Radiological examinations assist in identification, locating foreign objects such as projectiles, and documenting old and recent bony injury, which is of particular importance in suspected child abuse, when full body X-rays are required. Angiography and more sophisticated techniques such as computerized tomography (CT) and nuclear magnetic resonance (NMR) scanning may be useful in special circumstances.
1159
For many deaths the information obtained from the history, scene of death and external examination is sufficient and no dissection of the body is required. Such a postmortem external examination of the body is distinguished from an autopsy, which always involves dissection. The purpose of continuing the examination with a dissection is to obtain further information not otherwise available. This internal examination almost always requires the opening of all three body cavities, namely the head, chest and abdomen. In some jurisdictions the opening of all three body cavities is mandatory under regulations governing the conduct of medicolegal autopsies. Even where no such rules exist, it is unwise to omit the examination of any of the three cavities. Such an incomplete autopsy fosters lingering doubts, brings into question the competence and judgment of the pathologist and may unnecessarily precipitate a reopening of the investigation. It is a particularly undesirable practice where the body is to be shipped overseas for disposal, when distance and the differences in language, culture and legal processes combine to compound misunderstandings.
Internal Examination The internal examination of the chest and abdominal cavities is made through a large midline incision to the anterior chest and abdominal wall. This may be a simple linear incision from lower neck to pubic symphysis, a T-shaped incision from shoulder to shoulder and lower neck to symphysis, or a Y-shaped incision sparing the lower neck and upper chest. The choice of incision is dictated by the required exposure, but also by the cosmetic effect, bearing in mind the likely funerary arrangements. The chest plate is removed as a triangle of sternum and costal cartilages and the internal organs removed as a single block, as groups of organs, or as single organs, depending upon the preference and the judgment of the pathologist. When the organs are removed singly, the order of their removal may be modified according to the specific requirements of the case. All of the internal organs including the pelvic organs, comprising the bladder, internal genitalia and rectum, are removed. Using a coronal incision of the scalp, from ear to ear, the scalp is peeled forwards and back to expose the cranial vault, the top of which is cut off to allow removal of the brain and examination of the interior of the skull. The major organs are always weighed and the weights recorded. Where no special techniques are employed the method of dissection is similar to that of a `hospital' autopsy. As well as recording evidence of trauma and natural disease, important negative observations, such as the absence of coronary artery disease, pulmonary
1160 PATHOLOGY/Autopsy
thromboemboli and bony fractures, are also recorded. This serves to provide valuable exclusionary information, and to document the completeness of the internal examination. The quality of documentation required of both the external and the internal examinations is that sufficient for another pathologist to reach a reliable independent interpretation of the findings. Special techniques
Some types of trauma and complications of trauma require special autopsy techniques. In cases of suspected assault the muscles of the anterior shoulders, the anterior abdominal wall and the back are examined. If these muscles are not exposed and dissected then bruises within them may escape detection, particularly since there is often no visible injury on the skin surface. Venous air embolism is a potentially lethal condition and can cause sudden death in association with abortion, labour or penetrating injuries to the neck, such as stab wounds. The diagnosis may be suspected from the circumstances of the death but ultimately rests upon the observation of air in the right side of the heart and great veins at the time of autopsy. This air may be seen on a chest or abdominal X-ray of the decedent. Careful exposure of the inferior vena cava and the opening of the heart under water at the very beginning of the dissection of the body is essential if it is to be visualized. If not considered at the outset, air embolism is easily missed and the evidence destroyed by the routine dissection procedure. Deaths related to abortion, labour or violent sexual assaults require the removal of the internal genitalia in continuity with the external genitalia and perineum. The most important special dissection technique used in forensic pathology is the dissection of the neck. Pathological findings in the neck are of crucial importance in deaths from hanging, ligature strangulation, manual strangulation and impacts to the head and neck. In these cases the physical evidence of injury may be very little when contrasted with the fatal outcome. The forensic dissection technique allows for examination of the neck structures in situ, layer by layer, in a bloodless field, i.e. after draining the neck of blood. In this way the creation of false hemorrhages as a result of the dissection technique is avoided, and even tiny areas of true hemorrhage can be identified. Failure to use this technique may result in the production of false hemorrhages, which are then erroneously interpreted as evidence of trauma in life. Ancillary investigations
Ancillary investigations, which support the medicolegal autopsy, include a potentially large range of hospital laboratory tests and forensic laboratory
examinations. In practice, the most important of these is toxicology because of the prevalence of prescribed and illicit drug usage, which may represent a cause or contributory factor in a death. Approximately one-third of all unnatural deaths have evidence of recent alcohol ingestion, and consequently alcohol analysis is the most common toxicological investigation. Specimens for toxicological analysis should include peripheral blood (and not blood from the torso), vitreous fluid, urine and liver, as well as stomach contents where there is suspicion of recent ingestion. The original volume of the gastric contents should be recorded so that the drug concentration found in a sample on toxicological analysis can be used to calculate the mass of drug in the stomach. Stomach contents may also be relevant to estimation of time of death. Biochemical studies can be performed on blood, urine, cerebrospinal fluid and vitreous fluid, although potential testing is more limited than in the living because of interfering postmortem biochemical changes. Samples from all major organs should be preserved in formaldehyde for possible histological examination, the extent of which is at the later discretion of the pathologist. Histological examination may identify disease states not apparent during autopsy dissection and assist in aging injuries and natural diseases, such as myocardial infarction. Samples for microbiological analysis are taken in accord with hospital autopsy practice and are of particular importance in the forensic setting of a sudden infant death, when occult infection is a common cause. Increasingly, DNA samples are obtained at autopsy for purposes of identification, archiving or the deletion of decedents from DNA criminal databases.
Report and Certification The endproduct of the autopsy is the written and signed report submitted to the legal authority instructing the examination. The pathologist should retain a duplicate signed original. The report should contain all relevant administrative information, such as the time, date and place of examination, the authorizing legal authority and the method of identification of the body, as well as the examination findings, results of ancillary investigations and chain-of-custody details. The report should always include a section offering an opinion on the interpretation of the autopsy findings in the light of the other available investigative information. Only the pathologist is in a position to advise the legal authorities on the significance of the autopsy findings, and to fail to do so through a permanent written record defeats the purpose of the autopsy. In some jurisdictions a pathologist may omit this opinion in a contentious
PATHOLOGY/Histopathology
case, such as a death in custody or an alleged extrajudicial killing, because of fear of reprisals or because of political sympathy with the state authorities. The absence of a full, fair and frank opinion at the conclusion of an autopsy report is always a matter of concern, but particularly in these cases. In those countries where the practice of offering no interpretative opinion in such contentious deaths has become institutionalized, it serves as a marker for the corruption and lack of independence of the medicolegal death investigative system. In addition to the autopsy report, the death certificate provides a documentary record of the death. The person who signs the death certificate records not only the cause of death but also the identity of the person and the time and place of death. In some death investigative systems this responsibility rests with the legal authority, such as the coroner, but in other jurisdictions it may lie with the autopsy pathologist. Formulation of the cause of death on the death certificate is in accordance with international rules approved by the World Health Organization. These rules were established primarily to allow for the classification and coding of deaths with a view to acquiring community-based statistics for health monitoring and planning purposes. A cause of death formulated according to these rules cannot express the complexities which may be of interest in legal proceedings, so that, in the courtroom, the certified cause of death represents only the starting point for comment. See also: Causes of Death: Scene of Death. Pathology: Post-mortem Interval.
Further Reading Randall BB, Fierro MF and Froede RC (1998) Practice guideline for forensic pathology. Archives of Pathology and Laboratory Medicine 122:1056±1064.
Histopathology M A Green, University of Sheffield, Sheffield, UK Copyright # 2000 Academic Press doi:10.1006/rwfs.2000.0588
Histology (the microscopical examination of tissues) forms an integral part of modern pathological investigation. In 1991, the British Royal College of Pathologists issued guidelines for the performance
1161
and reporting of hospital autopsies in which it was stated that `an autopsy is incomplete without histological examination of all major organs'. The same is true of the forensic autopsy. Histology is essential to confirm the nature of any natural disease noted during the naked eye examination, to identify those not visible to the naked eye (e.g. myocarditis) and is also applied in an endeavor to age injuries and natural disease processes such as myocardial infarction. Over the last half century, advances in histopathological techniques such as enzyme histochemistry have been applied to forensic studies, but with very limited success. Like temperature recordings as a method for estimating postmortem interval, changes in tissues, whether due to disease or injury, are subject to numerous variables, and any conclusion drawn from such studies must be hedged about with qualifications. General histopathology has made great strides in recent years. Immunocytochemistry, tumor markers, aspiration techniques and flow cytometry are routinely used in diagnosis. They have proved of limited value to the forensic pathologist. Even so, this is no excuse for limiting the amount or failing to take histology as a routine. Formalin-fixed organs and tissues can be kept for weeks or months, and once appropriately embedded in paraffin wax, they can be stored more or less permanently. Ideally, blocks from the major organs, heart, lung, liver, kidney, spleen and brain, should always be taken, and hematoxylin± eosin (H & E) stained sections should be examined. Unfortunately, in many jurisdictions such comprehensive practise is limited by both cost and time. In the investigation of unexpected infant deaths, the collection of tissue should be even wider. The British Confidential Enquiry into Sudden Death in Infancy (CESDI) lays down a protocol that requires the examination of more than 40 blocks selected from specific sites within a wide range of organs. The selection and preparation of blocks in itself poses problems. Blocks taken `at the table' from the brain are of little value; the brain should be fixed for at least 8 weeks, and preferably 12 weeks, before `blocking out' is undertaken. Similarly, the hearts of middleaged or elderly subjects should not only be formalin fixed, but decalcified if an adequate examination of the coronary artery system is to be made. Every forensic pathologist should have access to a laboratory capable of cutting frozen sections, providing sledge microtome facilities for cutting large tissue blocks, and employing technicians skilled in the selection and use of special stains. Furthermore, pathologists should conform to standard site selection protocols, for example for the examination of the brain and heart, so that their work can be subjected
part provided through major institutes of forensic science, and a number of these exist in association with institutes of forensic medicine and pathology. Given the concentration upon basic biological principles in undergraduate medical training, it is not surprising that a forensic pathologist often has the necessary expertise to take part in forensic biological service work and to give expert evidence in the field of forensic biology. Today, the forensic application of developments in molecular biology involving the analysis and comparison of DNA has been one of the great success stories of forensic biology. Forensic pathologists are often well equipped to analyze and comment on the general use of these techniques. Forensic toxicologist
Medical pharmacology and therapeutics form part of the basic education of all legally qualified medical practitioners. Knowledge of drugs and their normal and abnormal effects on the human body are fundamental to medical practice. While most doctors understand the toxic effects of therapeutic and some nontherapeutic drugs, details regarding the wide range of substances that are dangerous to the human body exceed the knowledge of most doctors. It is scientists specializing in forensic toxicology who screen and analyze human tissues for drugs and toxins. Forensic pathologists have a specific interest in this area. This is because the forensic pathologist has to determine issues relating to the cause of death and circumstances of death of individuals. Where such deaths are apparently the result of toxic substances, then a forensic pathologist must collect the appropriate body samples and, together with a forensic toxicologist, arrange for the most appropriate analysis. Medical detective
Forensic pathologists, more than all other specialists in medical practice, are medical detectives. They are involved in all phases of a death investigation and form part of the detection team that analyses the circumstances of a death. This role of medical detective is often glorified in the media, where the forensic pathologist is frequently elevated to the key player in the investigation. In reality the forensic pathologist participates on an equal basis with all other specialist investigators in the team investigating a death. Forensic pathologists provide far more than an autopsy service for the justice system. Their unique range of skills and expertise overlaps many of the traditional scientific, medical and legal compartments, and as such can be a highly effective and efficient resource for investigators.
1155
See also: Education: An International Perspective. Toxicology: Overview. Legal Aspects of Forensic Science:
Further Reading Brodrick Committee Report (1971) Cmnd. 4810 Report of the Committee on Death Certification and Coroners. London: Home Office. Gonzalez-Crussi F (1987) Three Forms of Sudden Death: and Other Reflections on the Grandeur and Misery of the Body. London: Picador. Hill RB and Anderson RE (1988) The Autopsy: Medical Practice and Public Policy. Boston: Butterworth. Knight B (1991) Forensic Pathology. London: Edward Arnold. Plueckhahn VD and Cordner SM (1991) Ethics, Legal Medicine and Forensic Pathology, 2nd edn. Melbourne: Melbourne University Press. Selby H The Aftermath of Death: Coronials. Leichhardt, NSW: Federation Press. Spitz WU and Fisher RS (1993) Spitz and Fisher's Medicolegal Investigation of Death: Guidelines for the Application of Pathology to Crime Investigation. Springfield, IL: Thomas.
Autopsy D J Pounder, University of Dundee, Dundee, UK Copyright # 2000 Academic Press doi:10.1006/rwfs.2000.0584
Introduction The autopsy, or necropsy as it is sometimes known in Britain, is a postmortem dissection of the body. The literal meaning of autopsy is `to see for oneself'. Autopsies are of two types: those performed in a hospital setting for purely medical purposes, and those performed under legal authority for forensic purposes. The `hospital' autopsy and the forensic autopsy address different questions and have different approaches. These differences are reflected in the conduct of the examination, the ancillary investigations, the significance attached to physical evidence, the approach to documentation, and the requirement for chains of custody. The `hospital' autopsy focuses on the internal examination of the body and the correlation of the findings with the clinical record. The broad purpose of the medicolegal autopsy is to gather evidence relevant to the investigation of a
1156 PATHOLOGY/Autopsy
death by legal authorities. The medicolegal autopsy has the purpose of establishing a cause of death; assisting in interpreting and correlating the facts and circumstances surrounding the death; recovering and preserving evidence; reconstructing how injuries occurred; establishing the identity of the deceased; estimating the time since death; providing an accurately observed record of the medical findings; and assisting in addressing the medicolegal aspects of public safety, public health and criminal and civil court proceedings.
Autopsy Strategy A medicolegal death investigation is much broader than the autopsy, and includes the scene of death examination and the gathering of witness and documentary evidence. The latter includes the social, psychiatric and medical history of the deceased. This background information informs and directs the conduct of the forensic autopsy. Every autopsy begins with a review of the available investigative information, an evaluation of the medicolegal issues arising, and the development of a strategy for the conduct of the autopsy. This strategy draws upon a repertoire of techniques, and structures the conduct of the postmortem examination to obtain the maximum amount of evidence relevant to the specific issues of the case. Such a strategy is inevitably flexible, as the ongoing examination may bring new information to light. Identification
Who, when, where, why, how and what are the questions that the autopsy assists in answering. Who has died is not usually at issue, but establishing identity can be a problem in some instances. There may be no circumstantial evidence of the identity of a person found dead, or visual identification may be impossible because of decomposition, fire damage, physical disruption or mutilation. In all of these circumstances special techniques will be required and then identification becomes a multidisciplinary effort. Radiology, dentistry, anthropology, law enforcement, criminalistics and molecular biology may be involved. The commonest methods of scientific individualization are fingerprints, dentistry and radiography. DNA analysis is increasingly used. The essential principle of individualized identification is to make a match between a unique feature, physically part of the body, and an antemortem record of that unique feature. This requires an accurate and reliable antemortem record. In exceptional circumstances it may be necessary to resort to the less robust methods of photographic superimposition and facial reconstruction.
Time and place of death
When the person died is usually best established from the circumstantial evidence, and is not commonly an important issue. However, it may be critical when alibi is the defence in a homicide, or when the sequence of deaths of family members killed in the same incident influences the inheritance of estates, or when life insurance policies have lapsed in the time between the disappearance of a person and the discovery of the body. Again, special techniques need to be applied to establish the time since death. Where the person died is usually where the body was found, but not always. Homicide victims may be dumped, and bodies may travel long distances in rivers and the sea prior to their recovery. The autopsy may provide evidence that the body has been moved after death, as well as trace evidence originating from the place of death. Cause of death
Establishing why the person died ± that is, the disease or injury initiating the sequence of events, short or prolonged, leading to death ± is one of the most important functions of the autopsy. However, the cause of death may be readily apparent from the circumstances and the condition of the body, such as a passenger in an air crash, and in these cases the autopsy is required for other investigative reasons, such as victim identification and accident reconstruction. There are many causes of death, both natural and unnatural, that cannot be established with certainty by autopsy alone. Examples include epilepsy, asthma and drowning. In such deaths the autopsy assists by excluding other potential causes of death from trauma, drugs or natural disease. In a forensic autopsy, the demonstration of the absence of injury or disease may be as important as the demonstration of unequivocal or occult injury. Some natural diseases, particularly coronary artery disease, are chronic and can kill at any time, so their identification at autopsy represents a potential cause of death but not necessarily the cause of death. Similarly, drugs such as alcohol, morphine and other opiates, to which individuals develop tolerance, may be found at autopsy in concentrations in blood sufficient to account for death but not necessarily lethal. Very minor injuries may be consistent with a subtle form of homicidal trauma, such as soft smothering, and sufficient to arouse suspicion but not provide conclusive proof. Only in a minority of deaths are there autopsy findings of a trauma, poisoning or natural disease incompatible with life, so that the cause of death is established with certainty by the autopsy alone. For the great majority of death investigations, establishing why the person died requires the integrated analysis of the autopsy findings and
PATHOLOGY/Autopsy
scene of death and anamnestic data. In a small number of deaths a thorough investigation, including an autopsy, may fail to establish the cause of death. Such a case is characterized as a `negative autopsy' in the English-speaking world and as a `white autopsy' in the Spanish-speaking world. Manner of death
How the person died ± that is, the manner of death ± is a single word description of the circumstances leading up to the death. The manner of death may be natural or unnatural, and if unnatural may be accidental, suicidal or homicidal. Deaths from alcohol and drug abuse are difficult to classify and in some jurisdictions are simply described as `unclassified'. For some deaths the manner may be undetermined, either because the cause of death is unknown or because the circumstances are unclear; for example, whether a drowning was accidental or suicidal. Responsibility for determining the manner of death always lies with the legal authority, but this may be the autopsy pathologist if the jurisdiction has a North American-style medical examiner system. Surrounding circumstances
Establishing what happened to the deceased ± that is, the totality of the events leading up to and surrounding the death ± is invariably the focus of any legal proceedings. The autopsy can assist in this by establishing objective evidence of some of the things that happened or, more commonly, evidence limiting what could have happened. In homicide investigations, the autopsy can provide information on victim position, weapon used, sequence of injuries, postinjury activities, period of consciousness, survival time, time of death, postmortem interference with the body and method of disposal.
Legal Authority The law, regulations and local administrative practices governing medicolegal autopsies vary from place to place. Wherever the jurisdiction, before the start of any autopsy there must be legal authority to proceed. Only the appropriate law officer can provide this authority, and he or she may be a judge, prosecutor, coroner or medical examiner. The consent of the next of kin is not required, and in most instances they have no effective means of objecting. However, ethnic and religious minorities who have principled objections to postmortem dissections have achieved the legal right of objection in some jurisdictions. The pathologist receiving the authority for autopsy should permanently record how it was received, from whom and
1157
when. The autopsy report will ultimately need an introductory statement of the legal authority upon which it was performed. The next requirement is a formal identification of the decedent by a method meeting the necessary legal requirements. In a case in which no court proceedings are anticipated, simply noting the details contained on the mortuary body tag and any accompanying documentation may suffice. In other circumstances visual identification of the decedent by next of kin, possibly in the presence of a pathologist, or the use of a scientific method may be required. Whatever method is used, it should be formally recorded in the autopsy report.
External Examination The medicolegal autopsy requires the accurate observation and accurate documentation of both the external and the internal examination findings. The external examination is an essential component of the postmortem examination and constitutes the first part of the forensic autopsy. In some deaths it may be appropriate to limit the postmortem examination to the external examination without internal dissection. This is a judgment to be made by the pathologist and law officer in light of the legal requirements, public health concerns, potential for criminal prosecution or civil litigation, resource constraints, and the religious and personal views of the next of kin. The external examination embraces everything on and upon the body, including clothing, physical evidence and medical paraphernalia. Clothing
Examination of the undisturbed clothing is a valuable part of the autopsy. In some jurisdictions the body is stripped naked by police officers or mortuary technicians before presentation to the pathologist, but this is an unwise practice. The clothing can provide a wealth of useful information on the lifestyle of the decedent, events surrounding the death and the cause of death. If the pathologist does not document the clothing then it is often not documented at all. Each article of clothing should be described in appropriate detail and, when the body is unidentified, details of the labels and laundry marks as well. Description of the clothing should include general descriptions of any disarrangement, damage and stains. Recovery of trace evidence from clothing may be undertaken either at the scene of death or in the autopsy room, depending upon local practice and the nature of the case. Trace evidence might include hairs, fibers, paint chips, glass fragments, vegetation and insects. The collection and storage of this trace evidence must meet the legal
1158 PATHOLOGY/Autopsy
requirements for the chain of custody. The appropriateness of the clothing should be assessed against the scene of death and anamnestic information, particularly in potential hypothermic deaths. Stains, scuffmarks and tears to clothing may assist in traffic accident reconstruction or in clarifying events surrounding a death. Gunshot holes and stab wounds to clothing provide useful information in themselves, but more so when correlated with the underlying injuries to the body. Bloodstain patterns to clothing may illuminate the events following trauma and the activities of the victim prior to collapse. Jewelry may provide evidence of identification; medical bracelets and necklaces may indicate a chronic disease; pockets may contain medication or drugs of abuse; and personal papers may give information on identity, medical history and lifestyle. Stains
Before removing clothing and personal effects, and cleaning the body of any stains, it may be necessary to make a permanent photographic record, particularly in a case of homicide. After removal of the clothing, a head-to-toe detailed examination of the naked body is made. In the first instance this external examination should document stains and soiling, general and specific identifying characteristics, evidence of medical intervention and postmortem changes. Stains to the exposed body surfaces may be described at the time of the examination of the clothing and supplemented with a description of stains to the whole body. The location, extent and type of staining or soiling can provide useful information. Blood flow patterns from wounds reflect body position after wounding; highvelocity impact blood splatter and gunshot residue stains on the hands may indicate suicide; `coffee grounds vomitus' around the mouth and melena staining of the buttocks suggest death from massive gastrointestinal hemorrhage; vomitus containing tablet debris raises the possibility of suicidal overdose. General descriptors
The general external description should include height, weight, build, sex, race, head and body hair, eyes, dentition, scars, tattoos and body piercings and evidence of natural disease, particularly ankle edema and varicose veins, which raise the possibility of a cardiovascular death. The back, anus and perineum, palms and soles must always be examined. A specific search for petechial hemorrhages in the eyelids, conjunctivae, inner lips, face and neck is mandatory because they are easily overlooked but of considerable importance in the diagnosis of asphyxia. The recording of postmortem changes to the body
does not usually include body temperature unless there is a specific concern about the time of death. Core body temperature obtained rectally, or by a liver stab, is required. The presence or absence, and the pattern, of postmortem lividity, rigor mortis and putrefaction are routinely observed and recorded. Postmortem lividity (livor mortis or hypostasis) reflects gravitational pooling of blood after death, and thus body position. Areas of contact pallor produced by pressure from clothing or adjacent objects should correlate with the scene of death findings. A pink lividity, rather than the usual purple-red, raises the possibility of death from carbon monoxide poisoning, cyanide or hypothermia. Rigor mortis, which develops some hours after death, fixes the body in the position in which it came to rest and should also correlate with the scene of death findings. Neither lividity nor rigor is of any substantial value in estimating time of death. Postmortem injuries produced during the recovery of the body or by the feeding of insects, birds, animals or crustaceans are recorded separately from injuries produced in life in order to avoid confusion. Medical intervention
In many deaths there is evidence of attempts at lifesaving medical intervention. Where disposable medical equipment is attached to the body this should not be removed at the scene of death but transported with the body to the mortuary to be recorded by the pathologist. The most common items are airways and solutions for intravenous infusion. All of these require description and an assessment of their correct placement, together with recording of any associated bleeding, bruising or other tissue damage. Emergency medical treatment is rarely documented in detail at the time it is given because of the urgency of the circumstances, and consequently the autopsy record is often the most complete and reliable record. It may be important in any civil litigation for malpractice. Injuries produced by medical intervention, particularly those in the neck, may be misinterpreted as assaultive if not viewed in context. Recording intravenous lines eliminates the possibility that the associated needle puncture marks may give rise to a false suspicion of intravenous drug abuse. Injuries
The final stage of the external examination is the documentation of injuries. These are described systematically, either by grouping them according to injury type and anatomical location, or by numbering them, without implying an order of infliction or ranking of severity. Each injury is characterized by its type
PATHOLOGY/Autopsy
± for example, bruise, abrasion, laceration, incised wound, stab wound, gunshot wound, burn ± and its general anatomical location. The precise anatomical site of an injury is recorded in cases of homicide or if it is of particular significance for the reconstruction of the circumstances ± for example, a single suicidal gunshot wound or an imprint injury from a vehicle striking a pedestrian. Precisely locating a wound is analogous to giving a latitude and longitude with respect to fixed landmarks, which may be the midline of the chest, the heel or top of the head, or any fixed bony prominence. The size, shape and other relevant features of the injury, depending on its type, are observed and recorded. For this purpose photography is of special value in documenting a wealth of detail. The individual external injuries are described in continuity with any associated internal injuries in the final autopsy report. However, of necessity, the practicalities of the dissection of the body may require that this is carried out in a somewhat disjointed fashion, particularly where there are a large number of wounds. All penetrating wounds, such as gunshot wounds and stab wounds, must be traced from their entry point through the body to their termination or exit point. All nonpenetrating injuries need to be associated with damage to the underlying tissues such as bony fractures, lacerated blood vessels and associated hemorrhage. Special procedures
Special procedures utilized during the external examination include photography for the purposes of identification and documentation. Infrared and ultraviolet photography will enhance tattoos, bruises and patterned injuries. High-contrast black-and-white photography or computer-directed image enhancement can be used to enhance patterned injuries. Trace material can be identified with ultraviolet, laser or alternative light sources. Fingerprinting may be required for identification purposes, and is routine for all homicide victims. Where sexual assault is suspected, the collection of physical evidence includes what would normally be collected in a living victim. Insect specimens, such as fly maggots, may be useful for estimating time of death or for toxicological studies. Gunshot residues can be collected from the skin surface. Radiological examinations assist in identification, locating foreign objects such as projectiles, and documenting old and recent bony injury, which is of particular importance in suspected child abuse, when full body X-rays are required. Angiography and more sophisticated techniques such as computerized tomography (CT) and nuclear magnetic resonance (NMR) scanning may be useful in special circumstances.
1159
For many deaths the information obtained from the history, scene of death and external examination is sufficient and no dissection of the body is required. Such a postmortem external examination of the body is distinguished from an autopsy, which always involves dissection. The purpose of continuing the examination with a dissection is to obtain further information not otherwise available. This internal examination almost always requires the opening of all three body cavities, namely the head, chest and abdomen. In some jurisdictions the opening of all three body cavities is mandatory under regulations governing the conduct of medicolegal autopsies. Even where no such rules exist, it is unwise to omit the examination of any of the three cavities. Such an incomplete autopsy fosters lingering doubts, brings into question the competence and judgment of the pathologist and may unnecessarily precipitate a reopening of the investigation. It is a particularly undesirable practice where the body is to be shipped overseas for disposal, when distance and the differences in language, culture and legal processes combine to compound misunderstandings.
Internal Examination The internal examination of the chest and abdominal cavities is made through a large midline incision to the anterior chest and abdominal wall. This may be a simple linear incision from lower neck to pubic symphysis, a T-shaped incision from shoulder to shoulder and lower neck to symphysis, or a Y-shaped incision sparing the lower neck and upper chest. The choice of incision is dictated by the required exposure, but also by the cosmetic effect, bearing in mind the likely funerary arrangements. The chest plate is removed as a triangle of sternum and costal cartilages and the internal organs removed as a single block, as groups of organs, or as single organs, depending upon the preference and the judgment of the pathologist. When the organs are removed singly, the order of their removal may be modified according to the specific requirements of the case. All of the internal organs including the pelvic organs, comprising the bladder, internal genitalia and rectum, are removed. Using a coronal incision of the scalp, from ear to ear, the scalp is peeled forwards and back to expose the cranial vault, the top of which is cut off to allow removal of the brain and examination of the interior of the skull. The major organs are always weighed and the weights recorded. Where no special techniques are employed the method of dissection is similar to that of a `hospital' autopsy. As well as recording evidence of trauma and natural disease, important negative observations, such as the absence of coronary artery disease, pulmonary
1160 PATHOLOGY/Autopsy
thromboemboli and bony fractures, are also recorded. This serves to provide valuable exclusionary information, and to document the completeness of the internal examination. The quality of documentation required of both the external and the internal examinations is that sufficient for another pathologist to reach a reliable independent interpretation of the findings. Special techniques
Some types of trauma and complications of trauma require special autopsy techniques. In cases of suspected assault the muscles of the anterior shoulders, the anterior abdominal wall and the back are examined. If these muscles are not exposed and dissected then bruises within them may escape detection, particularly since there is often no visible injury on the skin surface. Venous air embolism is a potentially lethal condition and can cause sudden death in association with abortion, labour or penetrating injuries to the neck, such as stab wounds. The diagnosis may be suspected from the circumstances of the death but ultimately rests upon the observation of air in the right side of the heart and great veins at the time of autopsy. This air may be seen on a chest or abdominal X-ray of the decedent. Careful exposure of the inferior vena cava and the opening of the heart under water at the very beginning of the dissection of the body is essential if it is to be visualized. If not considered at the outset, air embolism is easily missed and the evidence destroyed by the routine dissection procedure. Deaths related to abortion, labour or violent sexual assaults require the removal of the internal genitalia in continuity with the external genitalia and perineum. The most important special dissection technique used in forensic pathology is the dissection of the neck. Pathological findings in the neck are of crucial importance in deaths from hanging, ligature strangulation, manual strangulation and impacts to the head and neck. In these cases the physical evidence of injury may be very little when contrasted with the fatal outcome. The forensic dissection technique allows for examination of the neck structures in situ, layer by layer, in a bloodless field, i.e. after draining the neck of blood. In this way the creation of false hemorrhages as a result of the dissection technique is avoided, and even tiny areas of true hemorrhage can be identified. Failure to use this technique may result in the production of false hemorrhages, which are then erroneously interpreted as evidence of trauma in life. Ancillary investigations
Ancillary investigations, which support the medicolegal autopsy, include a potentially large range of hospital laboratory tests and forensic laboratory
examinations. In practice, the most important of these is toxicology because of the prevalence of prescribed and illicit drug usage, which may represent a cause or contributory factor in a death. Approximately one-third of all unnatural deaths have evidence of recent alcohol ingestion, and consequently alcohol analysis is the most common toxicological investigation. Specimens for toxicological analysis should include peripheral blood (and not blood from the torso), vitreous fluid, urine and liver, as well as stomach contents where there is suspicion of recent ingestion. The original volume of the gastric contents should be recorded so that the drug concentration found in a sample on toxicological analysis can be used to calculate the mass of drug in the stomach. Stomach contents may also be relevant to estimation of time of death. Biochemical studies can be performed on blood, urine, cerebrospinal fluid and vitreous fluid, although potential testing is more limited than in the living because of interfering postmortem biochemical changes. Samples from all major organs should be preserved in formaldehyde for possible histological examination, the extent of which is at the later discretion of the pathologist. Histological examination may identify disease states not apparent during autopsy dissection and assist in aging injuries and natural diseases, such as myocardial infarction. Samples for microbiological analysis are taken in accord with hospital autopsy practice and are of particular importance in the forensic setting of a sudden infant death, when occult infection is a common cause. Increasingly, DNA samples are obtained at autopsy for purposes of identification, archiving or the deletion of decedents from DNA criminal databases.
Report and Certification The endproduct of the autopsy is the written and signed report submitted to the legal authority instructing the examination. The pathologist should retain a duplicate signed original. The report should contain all relevant administrative information, such as the time, date and place of examination, the authorizing legal authority and the method of identification of the body, as well as the examination findings, results of ancillary investigations and chain-of-custody details. The report should always include a section offering an opinion on the interpretation of the autopsy findings in the light of the other available investigative information. Only the pathologist is in a position to advise the legal authorities on the significance of the autopsy findings, and to fail to do so through a permanent written record defeats the purpose of the autopsy. In some jurisdictions a pathologist may omit this opinion in a contentious
PATHOLOGY/Histopathology
case, such as a death in custody or an alleged extrajudicial killing, because of fear of reprisals or because of political sympathy with the state authorities. The absence of a full, fair and frank opinion at the conclusion of an autopsy report is always a matter of concern, but particularly in these cases. In those countries where the practice of offering no interpretative opinion in such contentious deaths has become institutionalized, it serves as a marker for the corruption and lack of independence of the medicolegal death investigative system. In addition to the autopsy report, the death certificate provides a documentary record of the death. The person who signs the death certificate records not only the cause of death but also the identity of the person and the time and place of death. In some death investigative systems this responsibility rests with the legal authority, such as the coroner, but in other jurisdictions it may lie with the autopsy pathologist. Formulation of the cause of death on the death certificate is in accordance with international rules approved by the World Health Organization. These rules were established primarily to allow for the classification and coding of deaths with a view to acquiring community-based statistics for health monitoring and planning purposes. A cause of death formulated according to these rules cannot express the complexities which may be of interest in legal proceedings, so that, in the courtroom, the certified cause of death represents only the starting point for comment. See also: Causes of Death: Scene of Death. Pathology: Post-mortem Interval.
Further Reading Randall BB, Fierro MF and Froede RC (1998) Practice guideline for forensic pathology. Archives of Pathology and Laboratory Medicine 122:1056±1064.
Histopathology M A Green, University of Sheffield, Sheffield, UK Copyright # 2000 Academic Press doi:10.1006/rwfs.2000.0588
Histology (the microscopical examination of tissues) forms an integral part of modern pathological investigation. In 1991, the British Royal College of Pathologists issued guidelines for the performance
1161
and reporting of hospital autopsies in which it was stated that `an autopsy is incomplete without histological examination of all major organs'. The same is true of the forensic autopsy. Histology is essential to confirm the nature of any natural disease noted during the naked eye examination, to identify those not visible to the naked eye (e.g. myocarditis) and is also applied in an endeavor to age injuries and natural disease processes such as myocardial infarction. Over the last half century, advances in histopathological techniques such as enzyme histochemistry have been applied to forensic studies, but with very limited success. Like temperature recordings as a method for estimating postmortem interval, changes in tissues, whether due to disease or injury, are subject to numerous variables, and any conclusion drawn from such studies must be hedged about with qualifications. General histopathology has made great strides in recent years. Immunocytochemistry, tumor markers, aspiration techniques and flow cytometry are routinely used in diagnosis. They have proved of limited value to the forensic pathologist. Even so, this is no excuse for limiting the amount or failing to take histology as a routine. Formalin-fixed organs and tissues can be kept for weeks or months, and once appropriately embedded in paraffin wax, they can be stored more or less permanently. Ideally, blocks from the major organs, heart, lung, liver, kidney, spleen and brain, should always be taken, and hematoxylin± eosin (H & E) stained sections should be examined. Unfortunately, in many jurisdictions such comprehensive practise is limited by both cost and time. In the investigation of unexpected infant deaths, the collection of tissue should be even wider. The British Confidential Enquiry into Sudden Death in Infancy (CESDI) lays down a protocol that requires the examination of more than 40 blocks selected from specific sites within a wide range of organs. The selection and preparation of blocks in itself poses problems. Blocks taken `at the table' from the brain are of little value; the brain should be fixed for at least 8 weeks, and preferably 12 weeks, before `blocking out' is undertaken. Similarly, the hearts of middleaged or elderly subjects should not only be formalin fixed, but decalcified if an adequate examination of the coronary artery system is to be made. Every forensic pathologist should have access to a laboratory capable of cutting frozen sections, providing sledge microtome facilities for cutting large tissue blocks, and employing technicians skilled in the selection and use of special stains. Furthermore, pathologists should conform to standard site selection protocols, for example for the examination of the brain and heart, so that their work can be subjected