Background <p>Primary cardiac angiosarcoma is a rare and malignant tumor that most often arises in the right atrium causing significant inflow obstruction and circulatory disruption. Owing to its location, it is most often associated with symptoms similar to heart failure including lower extremity swelling, dyspnea, and chest pain. Other symptoms of venous congestion, including superior vena cava syndrome, are possible but symptoms vary widely depending on the location and size of the tumor and are rarely isolated.</p> Case presentation <p>In this case, a 69-year-old Filipino American female presented to our facility with isolated findings of superior vena cava syndrome that were ultimately secondary to cardiac angiosarcoma. The patient developed recurrent pericardial effusions that necessitated drain placement. She was managed with medical, chemotherapeutic, and radiation therapy in the outpatient setting. She subsequently was found to have worsening of metastatic disease that resulted in her passing.</p> Conclusion <p>Patients with cardiac angiosarcoma may present with atypical or nonspecific symptoms, such as with our patient presenting with isolated superior vena cava syndrome, and an atypical presentation may further delay the diagnosis. Late presenting cardiac angiosarcoma contributes to a worse prognosis and higher likelihood of metastasis at the time of diagnosis. Treatment typically includes chemotherapy and radiation but surgical excision, alone or in combination with other therapies, can provide the best prognosis. Early detection of cardiac angiosarcoma is crucial for improving outcomes.</p>