Acute hemorrhagic leukoencephalitis with a positive transfusion-related antibody screening test

A 65-year-old female patient visited the emergency department with a confusional mentality.The symptoms of the patient were initially suspected to be due to an overdose of her usual antipsychotics, and we planned to instantly discontinue her medications.However, her hemoglobin was observed to be 5.5 g/dL.Although the transfusion-related antibody screening test was positive, the patient received 1 point for packed red blood cells because of severe anemia.The same antibody screening test performed 10 years previously yielded negative results.She returned to the emergency department a day later with recurrent seizures.Brain magnetic resonance imaging (MRI) showed multiple patches of high signal intensity in the fluid-attenuated inversion recovery image and multiple leptomeningeal enhancements on contrast-enhanced T1-weighted imaging (Fig. 1).Cerebrospinal fluid analysis showed no pleocytosis, but the consciousness of the patient deteriorated to semicoma within 3 days.Follow-up brain MRI showed multiple diffusion-restrictive lesions with diffuse punctuated hemorrhages and extensive mass effect (Fig. 2).Posterior reversible encephalopathy syndrome (PRES) was considered as a differential diagnosis, but concomitant massive edema,