To review and report a case of sporadic cerebral amyloid angiopathy (CAA) with essential thrombocythemia (ET) with a JAK2 gene mutation and deep venous thrombosis (DVT), in order to provide clinical insights and discuss the treatment options.

The clinical data of a CAA patient with ET, caused by JAK2 gene mutation, and lower extremity DVT, admitted to the Department of Neurology of Peking Union Medical College Hospital in February 2024, were summarized and the diagnosis and treatment process with multidisciplinary collaboration were analyzed. We also reviewed previous reports about CAA complicated with ET and summarized the clinical characteristics, treatment conflicts, antithrombotic therapy decisions, and prognosis of these patients.

The patient was a 74-year-old female, who complained of cognitive decline for 1 year. Magnetic resonance imaging revealed multiple lobar cerebral microbleeds, cortical hemosiderin deposition, multiple white matter hyperintensities, and lacunes. According to the Boston 2.0 diagnostic criteria, the patient met the diagnostic criteria for probable CAA and was at high risk of spontaneous cerebral hemorrhage. Meanwhile, the patient was complicated with ET and DVT, which had indications for anticoagulant therapy. There was a dilemma in the therapy decision. After multidisciplinary discussion, a prophylactic dose of Rivaroxaban (10 mg/d) was given on the basis of a cytoreductive agent in combination with Hydroxyurea, and the risk factors of vascular disease were strictly controlled. The DVT was improved without cerebral microbleeds increasing in three-month follow-up, which may suggest the safety and effectiveness of our treatment. Previous research reported only one case of CAA with ET, in which the risk of bleeding was higher than the risk of thrombosis, antithrombotic therapy was discontinued to prevent bleeding.

In patients with CAA complicated by thrombotic diseases, it is necessary to weigh the risks of bleeding and thrombosis and make individualized decisions. For CAA patients with ET and DVT, if the risk of thrombosis outweighs the risk of bleeding, a prophylactic dose of anticoagulant therapy can be used on the basis of cytoreductive agent and controlling cardiovascular risk factors. A non-vitamin K antagonist oral anticoagulant is suggested. Close follow-up, dynamically evaluating, and adjusting the treatment are essential.