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: Surgery
[{'content': 'Keratoacanthoma is - \nSelect and explain. \nA. A type of basal cell carcinoma, B. Infected sebaceous cyst, C. Self healing nodular lesion with central ulceration, D. Pre-malignant disease', 'role': 'user'}, {'content': 'Answer: C \nExplanation: • Keratoacanthoma is self healing nodular lesion with central ulceration\n• More common in men, usually found on the face of 50–70 years old.\n• Lesions can grow to 1–3 cm over 6 weeks and typically resolve spontaneously over the subsequent 6 months.\nEtiopathogenesis\n• Classically a cup-shaped growth that exhibits symmetry about its middle.\n• Central crater is filled with a plug of keratin.\n• Unclear etiology (may be caused by HPV infecting a hair follicle)\n• Associated with smoking and chemical carcinogen exposure).\nTreatment\n• Removal of central keratin plug may speed resolution.\n• Excision is recommended for persistent lesions\n• Excision scar is often better than that which remains after resolution.', 'role': 'assistant'}]