This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Surgery
Which is the most common primary malignancy of hea ? 
Select and explain. 
A. Rabdomyosarcoma, B. Myxoma, C. Fibroma, D. Lymphoma
B: Myxoma
Answer: B: Myxoma 
Explanation: Myxoma is the most common primary neoplasm of hea (30- 50%). 75% of cardiac myxomas develop in the left atrium. Histologically, it is composed of a myxomatous stroma with large stellate cells mixed with multiWnuleated cells and covered with endothelium. Unusual benign tumors of hea are fibroma, lipoma, angioma, teratoma and cysts. Reference: Schwa'z Principles of Surgery 9e chapter 21.