Abstract Body (Do not enter title and authors here): A 66-year-old male presented with 5 months of worsening left flank and lower back pain. Three weeks prior to this presentation, he was seen at an outside facility where he was found to have a left renal mass that was not further worked up. CT Abdomen and Pelvis showed an enhancing heterogenous lesion at the left superior renal pole, left adrenal gland lesion, and a pulmonary artery filling defect. This defect, along with concern for metastasis, led to a CT chest angiogram that reported small left upper and lower lobe pulmonary emboli. A transthoracic echocardiogram (TTE) was ordered and showed a linear highly mobile mass in the right atrium that was intermittently protruding into the right ventricle and into the main pulmonary artery through the pulmonic valve. There was no visible evidence of tumor extension of the renal mass into the inferior vena cava. Based on this, the highest differential was a clot-in-transit. After collaboration with the pulmonary embolism response team and echo team, the patient underwent aspiration thrombectomy via AngioVac system with transesophageal echocardiography (TEE) guidance. Most of the mass was removed, but there was a residual small portion adherent to the superior vena cava that was not amenable to aspiration. Grossly, the removed mass did not have the classic appearance of thrombus. The specimen was sent to pathology and returned as poorly differentiated carcinoma with spindle cell pattern positive for PAX8, CK7, CD10, pancytokeratin, and vimentin concerning for renal cell carcinoma. Post procedural transthoracic echo found to have new basal septal globular mass with vascularity seen on echo contrast imaging concerning for vascular involvement consistent with myocardial metastatic invasion. Cardiac magnetic resonance imaging could have aided in more precise tissue characterization to differentiate between clot or tumor prior to aspiration thrombectomy. This case demonstrates the significance of a detailed history and physical exam, use of multimodality imaging, and multidisciplinary collaboration to manage a rare cardiac condition.