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: Pathology
[{'content': 'True about giant aneurysm -a) Rarely ruptureb) Most common in middle cerebral arteryc) Pressure effect is often the presenting symptomd) Thromboembolic phase is present \nSelect and explain. \nA. ab, B. bc, C. cd, D. ac', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Giant intracranial aneurysm\xa0\n\nA giant intracranial aneurysm is defined as one larger than 2.5 cm in diameter.\nGiant aneurysms are thought to represent about 5-8% of all intracranial aneurysms.\nThe three most common locations are:\n\n\nThe terminal internal carotid artery (most common)\nMiddle cerebral artery bifurcation\nTop of basilar artery\n\n\nSeventy to seventy-five percent of patients with giant aneurysm present with mass effect, usually manifest by visual defect, cranial nerve dysfunction, hemiparesis, seizures or headache.\nThrombosis and stroke due to blood clot formation within the aneurysm and subsequent distant embolus, occurs in some 2-5% of patients with giant aneurysm.\nSize does not influence the hemorrhage rate, and approximately 25% of patients present with subarachnoid hemorrhage due to rupture.', 'role': 'assistant'}]