Interpreting bruises at necropsy

Abstract

The accurate interpretation of bruising at necropsy is essential to understanding how a victim has been injured and assists the pathologist in a reliable reconstruction of the events leading to death. It is essential not only to assess the mechanism of production of a bruise, taking into account the type of impacting surface and the magnitude of force used, but also to estimate when the injury was caused. An account is given of the various methods used in the examination of bruises, particularly with respect to aging, as well as the factors that may aVect their appearance. DiVerentiation from artefacts resulting from postmortem changes is also discussed in some detail. (J Clin Pathol 2001;54:348-355) Keywords: bruising; necropsy; time of death; cause of death The interpretation of bruising for forensic purposes requires the pathologist to bear in mind the following three fundamental questions: + Is the discolouration seen a bruise? + When was it caused? + How was it caused?A succinct definition of a bruise is that it is a collection of blood, visible to the naked eye as an area of discolouration, which has extravasated into the surrounding tissues after vascular disruption, principally as a result of trauma or occasionally spontaneously, as a result of a disease process. Typically, bruises are caused by blunt trauma, although they may be associated with any type of impact and can accompany many diVerent types of wounds. Thus, they can provide much information with regard to their causation and can assist with the reconstruction of events leading to death.Furthermore, when an injury is inflicted and blood extravasates from injured blood vessels the resultant bruising may be: + Located at the area of impact and visible shortly after infliction of the injury. + Located at the area of impact area but delayed in appearance. + Located at a site away from the impact area and result from tracking of blood from the impact area. The word bruise is often used synonymously with the term haematoma and ecchymosis (or ecchymoma). Contusion is also another frequently used term, particularly in relation to internal trauma.Although bruising is most often thought of as an extravasation of blood intradermally or subcutaneously, bruises can occur almost anywhere in the body. Factors that influence the development and appearance of bruisesThere are many variables that influence the development and absorption of bruises, as well as their appearance and extent of spread, thus adding to the diYculty in their interpretation.Bruising occurs more easily where there is loose tissue-for example, over the eyebrowrather than where the skin is more strongly supported. It also occurs more readily where there is an excess of subcutaneous fat. Because there is a greater skin deposition of fat in women, they tend to bruise more easily than do men.The type of surface and force that impacts on the body will have a great eVect on the intensity, size, shape, and pattern of the resultant bruising.In infants and the elderly bruising tends to o...

Blunt Force Trauma in Veterinary Forensic Pathology

“…24 Slight or absent hemosiderin deposits cannot provide information on the time of wound infliction. 77 Erythrophagia precedes formation of hemosiderin within a contusion; however, only scarce information is available regarding the time when erythrophages first appear (Fig. 52); one report describes their appearance in hemorrhagic lungs within 30 minutes, 59 likely due to the constant presence of alveolar macrophages, while they have been shown to first appear in the skin within 15 hours.…”

“…74,77 However, this approach has been criticized for its unreliability. 26 In domestic animals, with the exception of poultry, 52 similar attempts have so far not been made, and the hair coat of most animals would likely hamper this determination.…”

“…In this area, neutrophils predominate over macrophages (approximate neutrophil/macrophage ratio of 4:1) at 12 to 16 hours, whereas at 16 to 24 hours, the ratio changes in favor of the macrophages (neutrophil/macrophage ratio of 1:2.5). Such studies 37,63,64 led to the development of a scheme for the histological assessment of open wounds 24,77 (Table 5). Consecutive phases of wound healing are histologically evident as an early phase of acute hemorrhage (Fig.…”

“…52); one report describes their appearance in hemorrhagic lungs within 30 minutes, 59 likely due to the constant presence of alveolar macrophages, while they have been shown to first appear in the skin within 15 hours. 77 Hematoidin is the final hemoglobin breakdown product (Figs. 50 and 54) and can be detected in animal tissues after 7 to 11 days.…”

Origin and assessment of bruises in beef cattle at slaughter

“…'Pseudo-bruises' that resemble true bruisesoriginated by machinery or handling of carcass at the slaughter line -such as hypostasis, congestion of blood or post-mortem injuries are artefacts. Artefacts from after death can lead to misinterpretation and require careful interpretation (Vanezis, 2001).…”