[Intra-alveolar hemorrhage: rare presentation of fat pulmonary embolism]

Fat embolism syndrome is a severe complication of long bone fractures, corresponding to the obstruction of small vessels by microdroplets of fat, originating from medulla ossium. Pulmonary involvement, present in 90% cases, makes the severity of the disease.

We report the case of a 22-year-old man who presented, two days after industrial accident causing an opened tibial fracture, acute dyspnea with hemoptysis. Angio-CT-scan didn't show any proximal vascular obstruction, but parenchymal sections showed diffuse, bilateral and multifocal hyperdensities predominating at the periphery. Broncho-alveolar lavage brought a hemorrhagic liquid, with a high macrophage content and lipid inclusions in macrophages. Exams for the etiologic diagnosis of intra-alveolar hemorrhage were negative: renal function, 24-hour proteinuria, antinuclear antibodies, antineutrophil cytoplasmic antibodies. The diagnosis of intra-alveolar hemorrhage secondary to fat embolism was established. The outcome was spontaneously favorable.

The occurrence of intra-alveolar hemorrhage in the course fat embolism is rarely reported. Its pathogenic mechanisms are not understood. It is mandatory to eliminate the other causes of alveolar hemorrhage before holding the diagnosis of fat embolism. Treatment is only symptomatic, based on respiratory reanimation.