This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Intracranial Space Occupying Lesion, Subject name: Medicine
Which is the most common type of primary CNS lymphoma in AIDS Positive patients? 
Select and explain. 
A. Centroblastic large cell lymphoma, B. Immunoblastic Large cell lymphoma, C. Anaplastic B- Cell Lymphoma, D. Lymphoplasmacytic Lymphoma
B: Immunoblastic Large cell lymphoma
Answer: B: Immunoblastic Large cell lymphoma 
Explanation: Primary CNS lymphoma -Immunocompetent patients is diffuse large B cell Lymphoma(DLBCL) -Immune deficient patients with HIV infected or organ transplant recipients on immunosuppression is Immunoblastic Large cell lymphoma(ILCL) Immunoblastic lymphoma is one of 3 morphologic variants of diffuse large B cell lymphoma (DLBCL): Centroblastic lymphoma Anaplastic B-cell lymphoma. Immunoblastic Large cell lymphoma