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': 'Cytogenetics for synovial cell sarcoma is - \nSelect and explain. \nA. t (X : 18), B. t (17, 9), C. t (9, 22), D. t (11,14)', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Synovial cell Sarcoma (SCS)\xa0\n\nSynovial cell sarcoma forms about 10% of all soft tissue sarcomas.\nAlthough the name suggests an origin from the synovial linings, less than 10% of them are intra-articular.\nMost synovial sarcomas show a characteristic chromosomal translocation t (X: 18) producing SYT-SS X1 or - SS X2 fusion genes. The specific translocation is associated with poor prognosis.\n60-70% of SCS involve the lower extremities, especially around knee and thigh.\nHistologic hallmark of biphasic synovial sarcoma is the dual lining of differentiation of the tumor cells (eg. epithelial\xa0like and spindle cells).\nCalcified concretions can be present on X-rays.\nThis tumor is positive for\n\n\nKeratin\nEpithelial membrane antigen.', 'role': 'assistant'}]