An asymptomatic patient undergoes sonography for possible engagement of the spleen on physical examination. The sonogram reveals a splenic length of 11.6cm and a 1.5cm round hyperechoic nodule in the superior aspect. These findings are most likely consistent with which of the following? A. Accessory spleen B. Hemangioma C. Angiosarcoma D. Hamartoma E. Splenomegaly