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: Surgery
[{'content': 'Malignant cells in urine cytology are most commonly seen in \nSelect and explain. \nA. Renal cell carcinoma, B. Prostate carcinoma, C. Urothelial carcinoma, D. Bladder carcinoma', 'role': 'user'}, {'content': "Answer: C \nExplanation: Ans. c (Urothelial carcinoma). (Ref. Harrison's Medicine 17th ed. 555)# Urothelial malignancy classically shows polychronotropism & multicentricity.# In urothelial or transitional carcinoma of renal pelvis or ureter, the examination of urine for malignant cells is positive and even may indicate whether tumor is well or poorly differentiated.# There is evidence that those with poorly differentited tumors do better if they have a short course of radiotherapy before surgery.# It is hence useful to obtain cells from tumor/urine by sampling a brush or catheter passes up the ureter under radiological control.", 'role': 'assistant'}]