This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Central Nervous System, Subject name: Pathology
[{'content': 'A 40 year old lady is diagnosed to have brain tumor in frontal lobe. The lesion is characterized by focal necrosis surrounded by ring like enhancement \nSelect and explain. \nA. Glioblastoma multiforme, B. Oligodendroglioma, C. Ependymoma, D. Astrocytoma', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ans. (a) Glioblastoma multiforme(Ref: Robbins 9th/pg 1307, Journal of Neuro-Oncology 108 (1): 11-27)When viewed with MRI, glioblastomas often appear as ringenhancing lesions. The appearance is not specific, however, as other lesions such as abscess, metastasis, tumefactive multiple sclerosis, and other entities may have a similar appearance. But necrosis with ring enhancement Is a f/o Glioblastoma multiforme.Oligodendroglioma usually shows calcifications.', 'role': 'assistant'}]