Fatal bone marrow embolism.

A 45-year-old man presented to the emergency department with fever, hypotension, respiratory distress, and altered mental status. Imaging revealed a femoral fracture and arterial blood gas showed severe metabolic acidosis. He died soon after admission. An autopsy revealed bone marrow particles in the lumen of numerous pulmonary arteries as well as fat emboli with admixed scattered hematopoietic cells in small vessels of the heart and liver. A clinical diagnosis of bone marrow embolism may be challenging due to its obscure presentation with possible multiorgan involvement. A definitive diagnosis is usually established postmortem with histopathological analysis of tissue collected during autopsy.