C51-23 A Rare Case of Leukemic CNS Vasculitis in Recurrent Refractory Acute Myeloid Leukemia

Abstract Introduction Neurologic manifestations of acute myeloid leukemia (AML) are rare in adults, encountered most often in severe refractory cases. We report a case of a 44-year-old female with recurrent refractory AML with worsening hyperleukocytosis and blast crisis. Head imaging revealed cortical ischemia with hemorrhagic transformation, suspicious for leukemic vasculitis, with subsequent neurologic deterioration and patient demise despite cytoreduction and emergent chemotherapy. Case Report A 44-year-old female with prior intravenous polysubstance use and recurrent refractory AML was transferred from an outside hospital for hyperleukocytosis 100,000 cells/µL.She endorsed persistent headaches with photophobia, nausea, and periorbital eye swelling. Labs revealed WBC count 63,150 cells/µL, blast count 23.37k/µL, hemoglobin 8g/dL, and platelets 22µL. Head CT/MRI revealed remote microhemorrhages, frontal scalp epidural leukemic infiltration, and thickened frontoparietal pachymeninges without parenchymal/leptomeningeal leukemic involvement. Given low suspicion for leukostasis, cytoreduction with hydroxyurea was initiated as a bridge to induction chemotherapy. On day 7, she became agitated, diaphoretic, and hypertensive (SBP 180 mmHg), with preserved neurological exam. Head CT revealed acute right subdural hemorrhage. Labs showed WBC count 29,140 cells/µL, peripheral blasts 11,360 cells/µL, and platelets 23 cells/µL. She became progressively encephalopathic, requiring intubation for airway protection. Head CT revealed new bifrontal subarachnoid hemorrhage. WBC increased to 128,710 cells/µL with blast count 82,560 cells/µL. Access complications delayed leukapheresis, prompting emergent chemotherapy with cladribine, idarubicin, cytarabine, and venetoclax. MRA head/neck revealed intracranial vasculitis with areas of ischemia and hemorrhagic transformation. Given rapid deterioration, further intervention was forgone, and she was terminally extubated. Discussion Central nervous system (CNS) complications in acute leukemia, though rare, are most often seen in relapsed or refractory disease and can lead to severe neurological impairment. One study reported an incidence of 0.6% on initial presentation and 2.9% in advanced or relapsed cases. Limited screening in the absence of concerning clinical features and a varied diagnostic modalities may lead to underdetection.Cerebral vasculitis in AML is exceedingly uncommon, with little published data regarding incidence or prevalence. In this case, initial imaging suggested intracranial hemorrhage likely related to thrombocytopenia and leukostasis. However, later development of cerebral edema, vessel caliber change, and widespread cerebral infarction with secondary hemorrhagic conversion strongly suggested CNS vasculitis. Conclusion This case emphasizes the importance of early recognition of CNS involvement in AML and serial brain imaging when suspicion arises. Despite timely detection, neurologic compromise remains likely. Delineation of leukostasis versus small-vessel vasculitis on imaging may be limited, and further investigation is warranted. This abstract is funded by: None