Seizures and Hyperleukocytosis Revealing New-Onset Acute Myeloid Leukemia During Acute COVID-19 Infection.

Acute myeloid leukemia (AML) with hyperleukocytosis is a hematologic emergency associated with high early mortality. Viral infections, including SARS-CoV-2, have been proposed as potential factors that may unmask previously undiagnosed leukemia or accelerate disease progression in predisposed individuals. We report the case of a previously healthy 61-year-old man who presented after recent travel with progressive fatigue, dizziness, fever, and multiple generalized seizures. Initial evaluation revealed COVID-19 infection with profound cytopenias and hyperleukocytosis, including a white blood cell (WBC) count of 132.9 × 10⁹/L, hemoglobin of 5.4 g/dL, and platelets of 11 × 10⁹/L. Peripheral smear demonstrated 36%-40% circulating myeloblasts with Auer rods, consistent with AML. Neuroimaging showed no intracranial hemorrhage. Laboratory evaluation revealed hyperuricemia, markedly elevated lactate dehydrogenase, hyperlactatemia (6.5 mmol/L), and acute kidney injury, concerning for early tumor lysis physiology. The patient was admitted to the intensive care unit and treated with hydroxyurea for cytoreduction, tumor lysis prophylaxis with allopurinol, transfusion support, and COVID-19-directed therapy. His leukocyte count decreased from 132.9 × 10⁹/L to 32.5 × 10⁹/L within 72 hours, with clinical stabilization. After initial cytoreduction and metabolic improvement, he was transferred to a tertiary oncology center for definitive induction therapy. This case raises the possibility that COVID-19-associated immune dysregulation may contribute to the clinical presentation of previously undiagnosed leukemia and underscores the importance of rapid cytoreduction, tumor lysis prevention, and multidisciplinary management in patients presenting with hyperleukocytic AML.