Case 1 -
The Pathology of Decomposition
Gregory G. Davis
Associate Professor, Forensic Division, Department of Pathology
University of Alabama at Birmingham
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When death occurs, the body begins undergoing a combination of autolysis, putrefaction, and
depredation by scavengers as it returns to the dust from which it came. Decomposing remains no longer
retain the subtle cytologic detail desired for diagnosis in surgical pathology, but careful examination
of even skeletal remains often reveals pathological changes sufficient to make a diagnosis of the cause
Decomposition begins with autolysis and proceeds to putrefaction at some point, depending on the
circumstances surrounding death and the environment surrounding the body.
Autolysis (fresh) Autolysis is a minor component of decay commonly seen in hospital autopsies.
Autolysis accounts for the softening of the pancreas and adrenal glands familiar from hospital autopsies.
Autolysis does not contribute to the next phase of decomposition, in which bacteria begin the process of
decay known as putrefaction.
Putrefaction the stage of decomposition in which the body stinks of decay until all soft
tissues are gone and only bones remain. Putrefaction occurs when the endogenous intestinal flora begin
to spread through the body from the gut. Exogenous bacteria and insects such as maggots begin to
colonize the body, primarily through the orifices, but most of the bloating caused by gas production is a
result of endogenous bacteria. The onset of putrefaction depends upon the condition of the decedent at
the time of death. For example, a patient who is septic at the time of death can begin to putrefy within
minutes, particularly in a hot room in summer. In contrast, in a case of a stillborn infant who is
wrapped and discarded in trash, putrefaction will be greatly slowed because the fetal gut contains no
endogenous bacteria. Times associated with decomposition thus vary widely. As a guide, for the body of
an adult left indoors at room temperature and with 50% relative humidity, the timing for putrefaction is
|Bloated stage (ends with expulsion of gases through orifices)
|•||Skin slip epidermolysis, skin slough, begins roughly 24 hours post mortem.|
|•||Marbling roughly 36 hours post mortem, bacteria grow in blood within veins of body|
|•||Bloating roughly 48 hours post mortem; body swells and fills with gases from bacteria|
|•||Discoloration roughly 48-72 hours; skin may turn green or black|
|Active decay begins when gases from bloating are expelled through orifices, anywhere from 3 days to several weeks depending on temperature; major tissue breakdown by carrion insects and bacteria|
|Dry/skeletal stage as quick as 2 weeks in the summer in the humid south, as long as months or years if body is buried in snow or if body preserved by special changes described below.|
|Animal activity may be on land or sea, by wild animals or by pets|
As mentioned above, a body sometimes undergoes changes which preserve it. Cold preserves, of course,
but other special environments, such as peat bogs in the British Isles, can also preserve remains. Two
preserving changes seen in North America are mummification and adipocere.
|Mummification drying of body, usually develops in warm, dry climates; skin is preserved but internal organs often are not. This finding would be more common in the deserts of the American Southwest.|
|Adipocere waxy change of fat, usually develops in high humidity or in water; bacterial enzymes of Clostridia (whether from intestines or environment) convert unsaturated fatty acids to saturated fatty acids. Tissue becomes greyish white with a soft, greasy consistency of clay. Adipocere tends to occur in water, whether fresh or salt, so it tends to occur along the coasts or in rivers.|
Identification of Remains
Regardless of the state of decomposition, the charge to a forensic pathologist remains
identify the remains and determine the cause and manner of death. Identification of unknown remains is
most easily accomplished by fingerprint comparison. In the absence of fingerprints there are other means
of establishing identification, but in that case identification will depend upon a combination of clues
and comparison of antemortem and postmortem records of the decedent.
|•||Visual identification by relatives or friends|
|•||Location of body (in home, for example)|
|•||Identification cards in pocket|
|•||Distinctive feature (ring, necklace, dog tag)|
|Scientific identification can be established by comparison of antemortem and postmortem
|•||Radiographs of bony structures|
Note that identification by either dental records, radiographs, or DNA comparison require that the
investigators have some inkling of who the decedent is, and thus clues are an essential first step in
trying to establish identification of remains.
Pathological Diagnosis in Setting of Decomposition
It is impossible to render a diagnosis such as mild cervical dysplasia on a body that has entered the
putrefactive stage of decomposition. The good news is that mild cervical dysplasia will not be the cause
of death in a case. Things that do cause death, such as bullets and knives, tend to leave some mark on
bony structures. Even strangulation can cause bony injuries detectable despite decomposition. Accidents
such as car wrecks leave bony fractures and the physical evidence of the wrecked car. In cases of
suicide by hanging the noose will still be evident, possibly with bony injury. Even natural diseases can
be detected in putrefying remains. Scar tissue is relatively resistant to decomposition, so extensive
myocardial scar and hepatic cirrhosis will both be detectable grossly and microscopically. The
persistence of crystals makes it possible to detect talc granulomas in sections of the lungs or oxalate
crystals in glomeruli from ethylene glycol consumption.
- DiMaio VJM, DiMaio DJ. Forensic Pathology, 2nd ed. New York: Elsevier, 2001.
- Spitz WU. Medicolegal Investigation of Death, 3rd ed. Springfield, IL: Charles C. Thomas, 1993.