This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Anatomy
Largest tumour of the ovary is 
Select and explain. 
A. Mucinous cystadenoma, B. Dermoid, C. Serous cystadenoma, D. All of the above
A: Mucinous cystadenoma
Answer: A: Mucinous cystadenoma 
Explanation: Mucinous cystadenoma Ovarian mucinous cystadenoma is a benign tumour that arises from the surface epithelium of the ovary. It is a multilocular cyst with smooth outer and inner surfaces. It tends to be huge in size. They often become very large and can extend up into the abdomen. Of all ovarian tumours, mucinous tumours comprise 15%.As it contains mucinous fluid, its rupture leads to mucinous deposits on the peritoneum (pseudomyxoma peritonei).