This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Respiratory system, Subject name: Pathology
[{'content': 'Macrophages with abundant cytoplasm containing dusty brown pigment are seen in \nSelect and explain. \nA. Desquamative Interstitial Pneumonia, B. Pulmonary Alveolar Proteinosis, C. Pulmonary Langerhans Cell Histiocytosis, D. Pulmonary Eosinophilia', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Desquamative interstitial pneumonia is characterized by large collections of macrophages in the airspaces in a current or former smoker. The macrophages were originally thought to be desquamated pneumocytes, thus the misnomer "desquamative interstitial pneumonia."The most striking finding is the accumulation of a large number of macrophages with abundant cytoplasm containing dusty brown pigment (smokers\' macrophages) in the airspaces.Ref: Robbins and Cotran Pathologic basis of DIsease; 9th edition; Chapter 15; The lung; Change 682', 'role': 'assistant'}]