Background Cardiac myeloid sarcoma is a rare extramedullary tumor of acute myeloid leukemia, and its optimal treatment strategy has not been established such as avoiding conventional anthracycline-containing induction chemotherapy because of unwanted cardiotoxicity. Recently, venetoclax combined with azacitidine was approved for newly diagnosed acute myeloid leukemia patients who are not unsuitable for intensive chemotherapy. To the best of our knowledge, there have been no reported cases of cardiac myeloid sarcoma treated with this combination regimen.Case presentation A 63-year-old man presented with progressive dyspnea on exertion. Echocardiography showed a massive pericardial effusion. Computed tomography of the chest revealed an infiltrative mass at the right atrioventricular groove with thickened epicardium and pericardium, and multifocal lymphadenopathy. Initially, he was suspected to have IgG4-related disease and Erdheim-Chester disease, based on elevated serum lgG4 levels and histopathological findings of axillary lymph node and endomyocardial biopsy. Despite treatment, his left ventricular systolic dysfunction rapidly deteriorated. Peripheral blood blasts were unexpectedly observed later, and subsequent bone marrow examination confirmed acute myeloid leukemia. Retrospective review of the endomyocardial biopsy specimen verified the diagnosis of cardiac myeloid sarcoma. To minimize the risk of chemotherapy-induced cardiotoxicity, we chose venetoclax plus azacitidine as induction therapy, followed by high-dose cytarabine consolidation and allogeneic hematopoietic stem cell transplant, which lead to a complete remission.Conclusions Although extremely rare, cardiac myeloid sarcoma can cause fulminant heart failure and should be included in the differential diagnosis of cardiac tumors, even without a prior history of hematologic disorders. Our report demonstrates for the first time that the combination of venetoclax and azacitidine is an effective and safe induction therapy for cardiac myeloid sarcoma.
