Hypertension for 2 years, palpitations, chest tightness, and a mass in the left retroperitoneal space found 5 months ago. Female, 35 years old. The patient reported that her blood pressure was found to be high 2 years ago, reaching a maximum of 220/180 mmHg, accompanied by excessive sweating, occasional dizziness, headaches, and palpitations but no fever, no cold extremities, and no fatigue. The patient was treated with oral medication for primary hypertension at a local hospital, but the blood pressure control was not satisfactory. In November 2020, the patient suddenly experienced palpitations and chest tightness without any obvious cause. She went to a local hospital for a checkup, and after completing CT, MRI, and other imaging examinations, a mass about 7 cm in size was found in the left retroperitoneal space, with uneven enhancement seen in the enhanced scan (Figs. 1, 2, and 3). The patient came to our outpatient clinic for further diagnosis and treatment and completed related endocrine tests, and 24-h urinary catecholamines showed NE 2113.15 μg/24 h, E 26.10 μg/24 h, and DA 580.08 μg/24 h; NMN 58.54 nmol/L. Considering the high possibility of pheochromocytoma, the patient was started on oral phenoxybenzamine 30 mg q 8 h at the end of November 2020. During the medication period, the patient’s general condition was good, and her blood pressure and heart rate were well controlled.