This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Respiratory, Subject name: Medicine
[{'content': 'A 25-year-old is seen in the clinic for assessment of an incidental finding on a CXR of a 2-cm solitary pulmonary nodule in the left lower lobe. He feels well and reports no dyspnea, chest pain, or constitutional symptoms. He does not smoke and has never had a previous CXR. The physical examination is completely normal. The nodule has a "popcorn ball"-type calcification pattern. Which of following is the most appropriate next step in management? \nSelect and explain. \nA. left lower lobe resection, B. serial CXRs, C. needle aspiration biopsy, D. left pneumonectomy', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Signs of benignity of a solitary pulmonary nodule are lack of growth over a prolonged period and certain patterns of calcification. "Popcorn" calcification does suggest a benign hamartoma. A search for previous CXRs can provide a definitive diagnosis. In nonsmokers under age 35, 1% of solitary pulmonary nodules are malignant. In this patient, a follow up CXR to demonstrate stability of the lesion is more appropriate than biopsy or resection.', 'role': 'assistant'}]