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
All of the following are true about medulloblastoma except? 
Select and explain. 
A. It is the most common primary malignant brain tumor in childhood, B. Isochrome 17q indicates poor prognosis, C. Most common site is brainstem (medulla), D. Tumor is highly radio sensitive
C: Most common site is brainstem (medulla)
Answer: C: Most common site is brainstem (medulla) 
Explanation: Medulloblastoma occurs exclusively in the cerebellum.