This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Ovarian Tumors, Subject name: Gynaecology & Obstetrics
In a case of Dysgerminoma of ovary one of the following tumor markers is likely to be raised. 
Select and explain. 
A. Serum HCG., B. Serum alphafetoprotein., C. Serum lactic dehydrogenase., D. Serum inhibin.
C: Serum lactic dehydrogenase.
Answer: C: Serum lactic dehydrogenase. 
Explanation: Placental alkaline phosphatase (PLAP) and lactate dehydrogenase (LDH) are produced by up to 95% of dysgerminomas, and serial measurements of LDH may be useful for monitoring the disease. A karyotype should be obtained preoperatively for all premenarcheal girls, paicularly those with dysgerminomas, because of the propensity of these tumors to arise in dysgenetic gonads