A 25-year-old female presented with right lumbago without palpitation, chest distress, and headache for 12 mo. On physical examination, palpation showed a giant mass without tenderness on the right upper abdomen; signs such as purple striae, moon face, and central obesity were not observed. The patient’s blood pressure was stable (120/80 mmHg). The renal function and metabolism of electrolytes were normal. Tumor markers such as carcinoembryonic antigen (3.14 ng/mL), alpha-fetoprotein (1.54 ng/mL), carbohydrate antigen (CA) 125 (12.8 U/mL), and CA199 (0.7 U/mL) and adrenal endocrinological examinations such as cortisol (7.56 µg/dL), aldosterone (162.7 pg/mL), metanephrine (34 pg/mL), and normetanephrine (69 pg/dL) were normal except for elevated serum β2-microglobulin (3986 ng/mL). The abdominal ultrasonography indicated a spherical solid mass (150 mm in diameter) in the right adrenal with a clear border and little blood flow signal. Abdominal magnetic resonance imaging (MRI) revealed a huge right adrenal tumor (181.5 mm × 115.0 mm × 107.2 mm), with diffused intralesional hemorrhage; the right lobe of the liver, right kidney, and inferior vena cava were significantly compressed. Surgery was performed under general anesthesia via a transabdominal L-shaped incision. The hypervascular tumor was adherent to the liver and tightly connected to the right kidney and inferior vena cava. The tumor was successfully removed and vital signs remained stable during operation. Macroscopically, the tumor was 200 mm × 160 mm in diameter and 1262 g in weight. The estimated intraoperative blood loss was 2000 mL. Severe complications were not observed and the patient was discharged 12 d after surgery.