Nonfracture-associated fatal fat embolism in a case of child abuse

Fatal fat embolism is usually thought of as a sequel to long-bone fracture, although cases secondary to soft tissue injury and atraumatic conditions have been infrequently reported. In this case of a two-year-old child-abuse victim who sustained multiple blunt traumatic injuries without skeletal fractures, pulmonary and systemic (brain and kidney) fat emboli were identified. At autopsy, all thoracic and abdominal viscera were intact; cranial contents exhibited only diffuse symmetrical petechial hemorrhages of the white matter. Because of the severe and widespread nature of soft tissue hemorrhage, and the absence of a grossly discernible cause of death, fat embolism was suspected. Using a combination of frozen section with oil red O staining and formalin-fixed osmium stained tissues, the immediate cause of death was determined to be diffuse fat embolism. Review of the literature reveals a pathophysiologic basis for fat embolism in the absence of fracture, both as a consequence of an acute increase in local pressure at the site of trauma and an alteration of the emulsification of blood lipids during shock. In light of these findings, we present this case to remind the forensic science community to consider fat embolism as the cause of death in cases of blunt-force injury without fracture.