The photograph shows a segment of ileum obtained at autopsy of a 74-year-old woman. Histologic examination reveals that the tumor arises from the submucosa and is composed of uniform round cells arranged in trabeculae. The liver shows multiple tan nodules of varying sizes. Electron microscopic studies performed on both the ileal tumor and the liver nodules show the presence of secretory granules. Which of the following cardiac changes would most likely be seen at autopsy?
A. Calcified masses on the aortic valve
B. Endocardial thickening of the right ventricle
C. Massive left ventricular dilation
D. Thrombus formation in the left atrium
E. Vegetations on the mitral valve