ANSWER 1: B. Although blood cultures could be considered, there is no history of constitutional symptoms or intravenous drug abuse, and endocarditis is unlikely. In situ thrombus would be unlikely, given the patient does not have atrial fibrillation. A mass should never be ignored, and a TEE will better delineate the structure as to size and attachment and so forth. A valvular lesion would raise suspicion for endocarditis, and a thrombus in transit from a venous leg or pelvic structure could be better identified with the TEE. Additional lesions in other areas of the heart may also be detected and aid in diagnosis. Furthermore, a lesion of this size should be considered for surgical removal, and the surgeons would need to have more information from the TEE before planning the surgery.