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: Radiology
[{'content': 'A 20 year female patient with 6th cranial nerve palsy on T2 weighted MRI shows a hyperintense lesion in cavernous sinus which shows homogenous contrast enhancement. Most probable diagnosis is? \nSelect and explain. \nA. Schwannoma, B. Meningioma, C. Cavernous sinus hemangioma, D. Astrocytoma', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Some guides have given schwannoma as the answer. They are wrong. Intense homogenous contrast enhancement is characteristic of meningioma.\n\n"Meningioma usually have similar characteristics to schwannomas, being isointense on T1\xa0image and hyperintense on T2\xa0weighted image. However; Homogeneous and significant contrast enhancement is a characteristic appearance\xa0of meningioma".\n\nSchwannomas show Heterogeneous (non-homogenous) and moderate contrast enhancement.\nRegarding 6th\xa0nerve palsy:-\n\n"Cavernous sinus (paracellular) meningiomas present with retro-orbital pain and sixth cranial nerve palsy". — Tumor neurosurgery: principles & practice.\nAbout option b & d\n\nOptic nerve glioma (Astrocytoma) is seen in children (first decade)\nCavernous hemangioma also shows homogenous contrast enhancement but it is a moderate enhancement (not intense). Further cavernous hemangioma does not cause 6th\xa0nerve palsy.', 'role': 'assistant'}]