This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Carcinoma Ovary, Subject name: Gynaecology & Obstetrics
All of the following are features of Borderline tumors except: 
Select and explain. 
A. Occurs in younger age, B. Mitotic figures <9/10 per high power filed, C. Very good prognosis, D. Stromal invasion seen
D: Stromal invasion seen
Answer: D: Stromal invasion seen 
Explanation: Ans. is d, i.e. Stromal invasionRef: Shaw gynae 15th/ed, p373-374Malignant tumor has 2 characteristics different from borderline tumors:(i) Stromal invasion present (it is absent in borderline tumor).(ii) Mitosis >=4/10 per high power field, (in borderline <4/10 per high power)