This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General anatomy, Subject name: Anatomy
Most common CNS neoplasm in HIV patient is 
Select and explain. 
A. Medulloblastoma, B. Astrocytoma, C. Primary CNS lymphoma, D. Ependymoma
C: Primary CNS lymphoma
Answer: C: Primary CNS lymphoma 
Explanation: Ref Robbins 9/e p254_255 It is the most common CNS neoplasia in those with AIDS It is of B cell origin and most have caused by EBV in the immunosuppressant persons Histologically reticulon stains demonstrate that the infiltrating cells are separate from one another by silverstraing material .this pattern referred as hopping is characteristics of primary brain lymphoma