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': 'Diagnostic feature of parathyroid carcinoma is ? \nSelect and explain. \nA. Cytology, B. Metastasis, C. Clinical features, D. All', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ans. is \'b\' i.e., Metastasis There is general agreement that a diagnosis of parathyroid carcinoma based on cytological detail is unreliable, and invasion of surrounding tissues and metastasis are the only reliable criteria". Robbins', 'role': 'assistant'}]