A 49-year-old woman with end-stage renal failure who had been maintained on chronic hemodialysis since she was 40 was referred to our hospital for surgical treatment of mitral regurgitation. She had no history of infectious endocarditis. Transthoracic echocardiography (TTE) performed at the referring hospital showed severe mitral regurgitation with severely impaired left ventricular function (ejection fraction, 33%). Both anterior and posterior leaflets of the mitral valve were thickened and the annulus was dilated. No calcification was identified in a cardiac chamber by TTE. Coronary arteriography showed total occlusion of the right coronary artery. Findings on transesophageal echocardiography were extremely unusual. A hyperechoic mass was attached to the inside wall of the sinus of Valsalva (Fig 1). Although the mass was not floating, the patient was transferred urgently to the operating theater for resection of the mass. After cardiopulmonary bypass was established and the heart arrested, the aorta was incised transversely. The mass was attached to the right coronary sinus, just above the right coronary ostium, and resembled an icicle (Fig 2). This mass was dissected carefully from the intima of aorta. It was heavily calcified and friable, although its surface was smooth. The aortic valve and aortic wall were not calcified. The mitral valve was replaced with a bileaflet mechanical valve, and aorto-coronary bypass to the right coronary artery was performed using a saphenous vein graft. The postoperative course was uneventful. Histopathologic examination confirmed that the mass was fibrous tissue with dense calcifications. Address reprint requests to Dr Fukui, Department of Cardiovascular Surgery, Shin-Tokyo Hospital, 473-1 Nemoto, Matsudo City, Chiba 2710077, Japan; e-mail: tm-fukui@gem.hi-ho.ne.jp. Fig 1. Fig 2.