<prompt> A 50-year-old man is found to have blood in his urine during a routine checkup. He is otherwise in excellent health, except for a mild microcytic, hypochromic anemia. An enlarged right kidney is found on X-ray examination, and CT scan reveals a renal mass of irregular shape, measuring 6 cm in diameter. Which of the following is the most likely diagnosis?AngiomyolipomaMetastatic carcinomaNephroblastomaRenal cell carcinoma  <response>: RCC is the most common cancer of the kidney, accounting for 90 of kidney cancers. Most cases of RCC are sporadic, but about 5 are inherited. The 5-year survival is 90 if the RCC has not extended beyond the renal capsule; survival drops to 30 if there are distant metastases. The tumor spreads most frequently to the lung and the bones. Oncocytoma and angiomyolipoma choice A are often difficult to differentiate from RCC by imaging techniques. Tumors such as nephroblastoma choice C and Wilms tumor choice E occur in the pediatric age group.Diagnosis: Renal cell carcinoma 