Cardiac sarcomas are exceptionally rare, with an incidence of only 0.02% and comprising less than 1% of all primary cardiac tumors. Consequently, diagnosis of the disease can be challenging due to non-specific presenting symptoms and diverse clinical manifestations. We present a unique case of cardiac sarcoma that highlights these challenges. A 70-year-old man with a history of hypertension, hyperlipidemia, and latent tuberculosis presented with palpitations, chest pain, and dyspnea, was found to have hemorrhagic pericardial effusion with tamponade. Pericardial fluid studies were negative for malignancy, and echo not suggestive of cardiac mass or pericardial abnormalities. He presented several months later with hemoptysis and was found to have innumerable pulmonary nodules on CT chest and a mediastinal mass adjacent to the right atrium. Bronchoscopy was negative for infection or malignancy. Ultimately the patient underwent CT-guided lung biopsy, which showed a malignant spindle cell neoplasm with a positive stain for vimentin and vascular markers suggestive of angiosarcoma of unknown primary. Given unclear relation of his mediastinal mass, cardiac MRI was done which showed a rapidly enhancing bulky neoplasm with abnormal contrast enhancement arising from the lateral right atrium (Figure 1) consistent with metastatic cardiac angiosarcoma. Patient was started on systemic anthracycline-based chemotherapy; however the overall prognosis remains poor. Given the rarity of cardiac sarcomas, prognosis is generally poor due to the advanced stage at the time of diagnosis. These tumors exhibit aggressive behavior and have a high propensity for metastasis. Due to their infrequency, knowledge and research is limited regarding effective treatments. This case highlights the significance of considering cardiac angiosarcoma in cases of hemorrhagic pericardial effusion even in the absence of obvious cardiac mass or pericardial nodularity on initial presentation.