Surgery to remove large adrenal tumors larger than 10 cm in diameter is extremely risky. Adequate preoperative preparation and skillful surgical technique are required to ensure the safety of surgery. Preoperative preparation Monitor blood pressure, blood glucose, blood potassium, blood sodium, and take alpha-blocker for preoperative preparation if blood pressure is too high, and take phenibutin at a dose of 20-60 mg/d, or take doxazosin controlled-release tablets at 4-16 mg/d for at least 7 days. If preoperative cardiac examination indicates arrhythmia or myocardial ischemia, a combination of antiarrhythmic and myocardial nutritional therapy will be given. If the fasting blood glucose is too high, treat with insulin routinely and maintain blood glucose at about 7 mmol/L. If necessary, intravenous potassium supplementation can be used. For severe hypokalemia, deep venous micro-pump potassium injection can be used to bring the blood potassium to normal values. Anesthesia: Intravenous inhalation complex anesthesia, routine measurement of invasive arterial pressure, opening of multiple veins, and preparation of rapid blood and fluid transfusion. The right tumor was closely located with the hepatic hilum, pancreatic head, duodenum and vena cava; the left tumor was closely located with the spleen, tail of pancreas and abdominal aorta. The huge adrenal tumor had unclear boundary with the surrounding tissues, especially the adhesion with large blood vessels, which made the operation very risky. Therefore, it is crucial to fully reveal the surgical field to determine whether the tumor can be resected. The authors performed the surgery through an abdominal incision without opening the chest in all patients with giant adrenal tumors. The right adrenal tumor is firstly separated from the sickle ligament of the liver, then the coronary ligament of the liver is opened, then the right triangular ligament is separated, and the right half of the liver is freed and held up, so that the upper pole of the right kidney, the right adrenal gland, the hilum, the lower portal vein, the upper vena cava and the posterior side can be exposed under direct vision, avoiding blind operation. In order to prevent accidental hemorrhage, the splenic artery can be ligated before separating the left giant adrenal tumor; the colonic splenic flexure, spleen and stomach can be adequately freed and turned to the left side to fully free the anterior part of the tumor, usually without sacrificing these vital organs. With adequate visualization, ligation of the central adrenal vein is the key to the procedure. If the tumor invades these organs, en block resection should be performed, i.e. planned resection of the tail of the pancreatic body and the spleen. It is important not to forcibly separate the adhesions between the tumor and these organs to avoid hemorrhage and tumor residue during surgery. 64-row CT image of left adrenal tumor (coronal view): showing the relationship between the tumor and kidney, spleen and abdominal aorta 64-row CT image of left adrenal tumor (cross-sectional view): showing the relationship between the tumor and spleen, pancreas and abdominal aorta