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: Gynaecology & Obstetrics
In a case of vesicular mole, all of following are high risk factors for the development of choriocarcinoma, EXCEPT: 
Select and explain. 
A. Serum HCG levels>1,00,000 mIu/ml, B. Uterus size larger than 16 week, C. Features of thyrotoxicosis, D. Presence of bilateral theca lutein cysts of ovary
B: Uterus size larger than 16 week
Answer: B: Uterus size larger than 16 week 
Explanation: High risk factors which indicates the development of choriocarcinoma at the time of diagnosis of a hydatidiform mole are: Maternal age more than 40 years Excessive uterine enlargement Serum hCG levels more than 100,000mIU/ml Theca lutein cysts greater than 6 cm in diameter Toxemia, hypehyroidism and coagulopathy Trophoblastic embolization Previously treated choriocarcinoma Ref: A Practical Approach to Gynecologic Oncology By Basu page 142.