An unusual case of pulmonary fat embolism following blunt trauma

Fat embolism is markedly underdiagnosed, even though it is a well-known phenomenon following fractures of the long bones, injury to subcutaneous fat tissue, rupture of a fatty liver, surgical operations on fatty tissues, septicemia, burns and barotrauma. Forensic pathologists tend to "simplify" autopsy report conclusion in cases with multiple injuries where fat embolism and exsanguination could be considered to be the concomitant causes of death. Herein we present a case of 24-year-old male who was beaten with a metal rod by several persons. On admission to hospital his vital signs and laboratory findings indicated hemorrhagic shock with gradual respiratory failure; he died 17 h after injury. On internal autopsy examination the subcutaneous tissue of the limbs and back was severely bruised, corresponding to about 35% of the body surface area. He had fractures of several small bones. Injuries of the internal organs were absent, there was no free blood in the body cavities, and all other autopsy findings were unremarkable but suggestive of a significant blood loss. Microscopic examination showed a massive pulmonary fat embolism (grade III according to Sevitt), without systemic fat embolism. The cause of death was attributed to pulmonary fat embolism combined with severe blood loss, following extensive and severe bruising of the subcutaneous tissues and bone fractures.