This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Salivary Glands, Subject name: Surgery
[{'content': "A 60-year-old male patient presents with a parotid lump and facial weakness (House Brackmann grade 6). A fine needle aspiration biopsy is arranged under ultrasound guidance. What is the likely cytology repo? \nSelect and explain. \nA. Pleomorphic adenoma, B. Wahin's tumor, C. Mucoepidermoid carcinoma, D. Oncocytic adenoma", 'role': 'user'}, {'content': "Answer: A \nExplanation: The fact that the elderly man has a facial palsy means that the disease is aggressive and invaded the facial nerve. Pleomorphic adenomas are benign lesions but have a propensity to become malignant (1% per year). These lesions are named carcinoma ex-pleomorphic adenoma. Wahin's tumors tend to occur bilaterally and more common in smokers. Ultrasound guided fine needle aspiration is helpful to get a possible cytological diagnosis. Core biopsy may be required if this in non-diagnostic, or excision of the gland may sometimes be the only way to confirm the diagnosis.", 'role': 'assistant'}]