Abstract
A 72-year-old man came to our hospital complaining of left hemiplegia. Acute ischemic stroke and occlusion of right middle cerebral artery were diagnosed, and conservative medical management was initiated. On the 13th day of hospitalization, echocardiographic examination showed a 0.8 × 0.8 × 3.5 cm mobile hyperechoic mass attached to right ventricular outflow tract (RVOT), but no chest symptoms were presented. While MRI also showed two stalks attaching the mass to the right ventricular outflow tract, we found it difficult to decide between thrombus and tumor. Because the mass was large enough to cause pulmonary embolism, we started administering unfractionated heparin and oral anticoagulant while considering surgical removal of the mass. Perfusion lung scintigraphy showed small defects in right lung fields. Subsequent transesophageal echocardiography showed disappearance of the tumor to be vanishing. The patient had no chest symptoms or thromboembolic complications. Lower leg venous echocardiography showed dilated veins in his left musculus soleus. We considered thrombus with a netlike structure moved from the left musculus soleus to the right ventricular outflow tract. In this patient, echocardiography was useful in making a differential diagnosis and in observing its clinical course.
