Occasionally, the fragile orbital roofs and ethmoid bone are so severely fractured as to allow pulpified brain tissue to be forced into the nasal sinuses and out the nostrils. This 34-year-old man was ejected during a motor vehicle accident. He sustained a crush injury of the anterior calvarium which extended through the orbital roof. Note the brain parenchyma extruding through the nostrils. Note the periorbital ecchymosis (raccoon eye).
Raccoon eye or periorbital ecchymosis is caused by blood tracking into periorbital tissues (the area around the eye), which is frequently observed after head trauma but is also observed in systemic diseases, such as amyloidosis, neuroblastoma, and surgical interventions.