A 48-year-old man presented to our endocrinology department for the evaluation of the left adrenal incidentaloma discovered during fatty liver assessment. Abdominal computed tomography revealed a 1.8 cm left adrenal incidentaloma (Hounsfield units 40). The results of laboratory findings were as follows: serum adrenocorticotropic hormone 54.3 pg/mL, cortisol 6.39 μg/dL, renin activity 0.41 ng/mL/hr, aldosterone 12.8 ng/dL, thyroid-stimulating hormone 4.86 mIU/L, and free thyroxine 1.30 ng/dL. The 24-hour urine collection results were as follows: epinephrine 12.82 μg/day, norepinephrine 43.71 μg/day, vanillyl mandelic acid 3.10 mg/day, cortisol 39.3 μg/day. The tumor I-131 metaiodobenzylguanidine (MIBG) scan showed no abnormal uptake. The patient was diagnosed with nonfunctioning adrenal incidentaloma, and was recommended for regular follow-up. The adrenal mass continuously increased from 1.8 cm in size at baseline to 2.7 × 2.3 cm at month 15, and finally to 8.0 × 4.3 cm after 6 years of follow-up suggesting a high possibility of malignancy (Fig. 1). No hormonal change was observed during follow-up. However, the patient refused surgical management several times for personal reasons. At last, after 6 years of follow-up, he received the surgery. The pathology revealed adrenal cortical carcinoma (ACC) with 4–5/10 high-power field (HPF) mitotic rate (Fig. 2). After surgery, the patient went through several systemic chemotherapy but expired due to recurrent multiple ACC metastasis.