Diagnosis and Management of Polycythemia Vera Complicated by Cerebral Infarction and Subdural Hematoma: A Case Report

ABSTRACT Myeloproliferative neoplasms are hematologic disorders associated with increased thrombotic and hemorrhagic risk. However, they are often underrecognized in patients presenting with cerebrovascular events. We report the case of a 70‐year‐old man who developed an acute cerebral infarction in the left temporal lobe accompanied by limb weakness. Neuroimaging revealed multiple cerebrovascular stenoses and widespread atherosclerotic vascular disease. During follow‐up, he developed a subdural hematoma. Further evaluation demonstrated persistent blood count abnormalities and splenomegaly. Bone marrow biopsy revealed a hypercellular marrow with trilineage proliferation (panmyelosis), characterized by prominent erythroid, granulocytic, and megakaryocytic lineages. Molecular testing revealed the Janus kinase 2 ( JAK2 ) Valine 617 Phenylalanine mutation. Combined with elevated hemoglobin levels, these findings fulfilled the diagnostic criteria for polycythemia vera in the fifth edition of the World Health Organization Classification of Haematolymphoid Tumors. This case highlights that coexisting ischemic and hemorrhagic cerebrovascular events with unexplained hematologic abnormalities or splenomegaly should prompt JAK2 mutation screening and bone marrow examination to enable early diagnosis of MPN and prevent further complications.