What are the typical postmortem findings in cases of drowning?

Postmortem Findings of Drowning

The diagnosis of drowning in postmortem examination relies primarily on a combination of circumstantial evidence and specific pathological findings, as there is no single pathognomonic sign that definitively confirms drowning as the cause of death. 1

External Findings

• External foam around the mouth and nostrils ("foam cone" or "mushroom") is present in approximately 17% of drowning cases, but is not specific to drowning 1
• Cutis anserina (goosebumps) may be observed on the skin 2
• Washerwoman skin (wrinkling of palms and soles) occurs after prolonged immersion but indicates only that the body was in water and not necessarily that drowning was the cause of death 2
• Paltauf spots (subpleural hemorrhages) may be visible externally in some cases 3

Internal Findings

Respiratory System

• Frothy fluid in the airways is found in approximately 46.5% of drowning cases 1
• Fluid in the airways (trachea and bronchi) is present in all drowning cases, typically showing central aspiration 4
• Emphysema aquosum (overinflated, ballooned lungs that meet at midline) due to bronchospasm is characteristic, with overlap of anterior lung margins observed in 42.1% of cases 1, 4
• Mosaic pattern of lung parenchyma on imaging due to regions of hypo- and hyperperfused lung areas from aspiration (60% of cases) 4
• Pulmonary edema, congestion, hemorrhage and emphysema on histological examination 3

Cardiovascular System

• Hypodensity of blood in the heart chambers (hemodilution) due to resorption of fresh water in the lungs 4
• Possible presence of air in the heart and major vessels in some cases 5
• Dilated right side of the heart may be observed 2

Gastrointestinal System

• Distended stomach and duodenum from swallowed water 4
• Fluid in the digestive tract is common but not universal 5

Head and Sinuses

• Water in the paranasal sinuses (100% of drowning cases) 4
• Fluid in mastoid air cells may be present 6

Diagnostic Challenges

• No single finding is pathognomonic for drowning, and the diagnosis relies on a constellation of findings 1, 6
• The association of external foam and overlap of lung margins is exclusive to drowning but observed in only 11.1% of cases 1
• Up to 60.6% of drowning cases may have no circumstantial data or macromorphologic findings that allow a definite diagnosis of drowning 1
• Many findings in drowning can also be present in non-drowning asphyxiation, making differentiation challenging 6

Advanced Diagnostic Methods

• Postmortem CT imaging can detect most typical drowning findings except Paltauf spots 4, 3
• Diatom testing of lung tissue samples compared with water samples from the scene can provide supportive evidence 3
• Combined approach using postmortem imaging and endoscopic autopsy can provide comprehensive findings while being minimally invasive 3

Important Considerations

• Precipitating events should be noted as they may confound the diagnosis, including:

  • Syncope or seizure
  • Impairment from drugs, alcohol, or hypothermia
  • Trauma
  • Cardiac events 2

• Duration of submersion is an important factor to document when possible 2

• Differentiation between drowning and other causes of death is crucial, especially in cases with evidence of trauma or preexisting medical conditions 2, 5