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': 'Which of the following malignancy shows rosette shaped arrangement of cells in histology? \nSelect and explain. \nA. Thecoma ovary, B. Ependymoma, C. Neurofibroma, D. Lymphoma', 'role': 'user'}, {'content': "Answer: B \nExplanation: Ependymomas are derived from ependymal cells, i.e., the cells lining the ventricles of the brain and the central canal of the spinal cord; this is the most common glioma of the spinal cord. These cells have both glial and epithelial characteristics. The most common cerebral site is the fouh ventricle; less often they occur in the lateral or third ventricles. The tumor cells tend to form rosettes with central lumens or, more often, circular arrangements around blood vessels (pseudorosettes). Ref: Ropper A.H., Samuels M.A. (2009). Chapter 31. Intracranial Neoplasms and Paraneoplastic Disorders. In A.H. Ropper, M.A. Samuels (Eds), Adams and Victor's Principles of Neurology, 9e.", 'role': 'assistant'}]