A 58-year-old man with a left adrenal mass (12 cm on CT) presents for surgical planning. Vital signs: BP 168/94 mmHg, HR 88/min, RR 14/min, temp 37.2°C. Laboratory studies show elevated 24-hour urinary metanephrines. He denies abdominal pain or flank tenderness. The surgeon plans a retroperitoneal approach via twelfth rib resection for tumor removal. Which structure is at greatest risk of iatrogenic injury with this surgical approach?

1. A)Stomach
2. B)Aorta
3. C)Vena cava
4. D)DiaphragmGABARITO
5. E)Pancreas