Unusual intravascular material in the brain. Autopsy findings in a patient treated with antihemophilic factor concentrates.

Widespread vascular occlusion caused by unusual particulate material in the brain of a patient who was intensively treated with antihemophilic factor (AHF) concentrates prior to death is described. The intravascular particles were seen partially or completely occluding both veins and arteries of small caliber in the brain and also to a much lesser extent in other organs. The resultant small focal infarcts were predominantly distributed in the cerebral white matter. The pathogenesis of this apparently unique vascular occlusive phenomenon and its relationship, if any, to the massive AHF concentrate infusion in this patient remain unknown.