Isolated thrombus-like mass in a patient with multiple myeloma

Abstract

A 55-year-old man was referred to our clinic to investigate the etiology of transient ischemic attack. He had no structural heart disease, atrial fibrillation, stroke, or renal or liver disease. However, he had been treated with thalidomide (200 mg/day) for three months due to multiple myeloma. He had received no antiaggregant or anticoagulant treatment. His physical examination was unremarkable. The electrocardiogram showed normal sinus rhythm. Routine laboratory tests were within the normal ranges. Both transthoracic (Video 1*) and transesophageal (Video 2*) echocardiographic examination demonstrated a pendulous mass suggesting a thrombus (24x12 mm) attached to the wall of the ascending aorta (Figure). The ascending aorta was not dilated, and no aortic dissection was observed. There was no thrombus-like image in the left atrium or left atrial appendage. Other echocardiographic parameters were also normal. No hereditary causes of atherothrombosis, such as factor V Leiden, prothrombin gene mutations, or antithrombin III, protein C and protein S deficiencies were found in the comprehensive hematologic examination. Therefore, the thrombus-like image in the ascending aorta was thought to possibly be due to an adverse effect of thalidomide. Surgical thrombectomy was recommended, but the patient refused this therapy and was lost to followup. The risk of thromboembolic events is increased in patients with multiple myeloma, especially in those treated with thalidomide-based regimens. Although a few cases of arterial thrombosis have been reported in these patients, a thrombus located in the ascending aorta has not been reported previously. Patients with multiple myeloma receiving thalidomide-based regimens with chemotherapy should receive thromboprophylaxis with either aspirin or low molecular weight heparin for lower-risk patients and low molecular weight heparin for higher-risk patients according to the guidelines of the American Society of Clinical Oncology. 413