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': 'Renal papillary necrosis is seen in \nSelect and explain. \nA. Sickle cell disease, B. Gouty nephropathy, C. Chronic glomerulonephritis, D. Tumor necrosis syndrome', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Necrotizing papillitis (or papillary necrosis): It is one special pattern of acute pyelonephritis and is much more frequent in diabetics Hyaline aeriolosclerosis narrows blood vessels -> reduces the blood supply to the renal medulla -> ischemia ->causes necrosis of the tips of papillae (papillary necrosis). Causes of necrotizing papillitis: Diabetes mellitus Sickle cell anemia Analgesic nephropathy Obstructive uropathy. Ref: RAM DAS NAYAK EXAM PREPARATORY MANUAL FOR UNDERGRADUATES 2nd ed. pg no: 615', 'role': 'assistant'}]