This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Renal carcinoma, Subject name: Pathology
[{'content': 'Most common histological variant of RCC is: \nSelect and explain. \nA. Clear cell carcinoma, B. Papillary carcinoma, C. Chromophobe carcinoma, D. Collecting duct carcinoma', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Renal cell carcinoma Clear cell carcinoma (70%) Sporadic (mc), Familial Papillary carcinoma (15%) Papillary growth pattern Familial and sporadic forms Chromophobe carcinoma (5%) Prominent cell membranes and pale eosinophilic cytoplasm, Halo around the nucleus. Collecting duct (Bellini duct) carcinoma (<1%) From collecting duct cells in the medulla', 'role': 'assistant'}]