This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Neuroradiology, Subject name: Radiology
Upstream and downstream hydrocephalus is seen in 
Select and explain. 
A. Ependymoma, B. Pineal germinoma, C. Choroid plexus papilloma, D. Meningioma
C: Choroid plexus papilloma
Answer: C: Choroid plexus papilloma 
Explanation: Most Brain tumors usually produce only upstream hydrocephalus. Choroid plexus papilloma is a CSF producing tumor located in occipital horns of lateral ventricle and produces both upstream and downstream hydrocephalus. CECT axial image showing intensely enhancing lesion in occipital horn of left lateral ventricle s/o Choroid plexus papilloma.