This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Urinary tract, Subject name: Pathology
[{'content': 'All of the following about Xanthogranulomatous pyelonephritis is true Except \nSelect and explain. \nA. On cut section yellowish nodules are seen, B. Associated with tuberculosis, C. Foam cells are seen, D. Giant cells are seen', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Xanthogranulomatous pyelonephritis It is an unusual and rare form of chronic pyelonephritis associated with Proteus infections. MORPHOLOGY Gross: Cut surface shows large, yellowish-orange nodules, which may be confused with renal cell carcinoma. Microscopy: Interstitium shows foamy macrophages, plasma cells, and lymphocytes Clinical Features Chronic pyelonephritis associated with reflux may be a silent onset. Usual symptoms are back-pain, fever, pyuria, and bacteriuria Ref: RAM DAS NAYAK EXAM PREPARATORY MANUAL FOR UNDERGRADUATES 2nd ed. pg no: 619', 'role': 'assistant'}]