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: Pathology
Ovarian tumours commonly arises from: March 2005 
Select and explain. 
A. Surface epithelium, B. Germ cell, C. Stroma of the ovary, D. None of the above
A: Surface epithelium
Answer: A: Surface epithelium 
Explanation: Ans. A: Surface epithelium Ovarian tumor arises from one of the tree main components: Surface epithelium Germ cells Stroma of the ovary. Most primary neoplasm in the ovary is epithelial tumours. Factors that decrease the risk for ovarian cancer predominantly reduce the number of ovulation cycles a women encounter, such as the use of oral contraceptives, breast-feeding and multiparity. Long-term use of oral contraceptives has reduced the risk of ovarian cancer by more than 50% in unselected women. Decreased risk of ovarian cancer has also been associated with tubal ligation and hysterectomy.