We present the case of a 20-year-old male who consulted for hypertensive crises of one year's duration, accompanied by profuse sweating, generalised flushing, headache and, occasionally, lumbar pain. Blood pressure levels reached 230/110 mmHg, often triggered by physical exertion. Physical examination revealed malar and palmar erythema, which disappeared with acupressure. Laboratory tests showed elevated 24-hour urinary catecholamines and metanephrines: noradrenaline excretion 7515.77 nmol/24 h (< 504), dopamine 4298.84 nmol/24 h (< 3237) and normetanephrines 39676 nmol/24 h (< 2424).
An abdominal ultrasound was performed, showing a retroperitoneal mass of about 8 cm, with heterogeneous echogenicity and marked vascularisation. In view of this finding, abdominal-pelvic computed axial tomography (CT) was performed, confirming the existence of a retroperitoneal mass measuring 8 x 4 cm above the aortic bifurcation, which infiltrated the inferior vena cava and bordered the aorta at 180o, encompassing the inferior mesenteric artery. Given the CT findings, cavography was performed to assess resectability, and an infrarenal intracaval repletion defect of 2 cm in diameter was observed.

Given the suspicion of paraganglioma of the organ of Zuckerkandl, beta and alpha-adrenergic blockade was performed, followed by surgical intervention with en bloc resection of the tumour; the anterior aspect of the cava was partially sectioned to remove the intracaval tumour. The postoperative period passed without complications, the clinical symptoms disappeared and the plasma and urine levels of catecholamines and metanephrines normalised.
The anatomopathological diagnosis confirmed the suspicion of a well-demarcated capsulated paraganglioma, with a low proliferative index (ki 67: 5-7 %). He was referred to Medical Oncology, where a 123I-MIBG scan was requested, which showed no signs of residual or distant disease. In the absence of data justifying adjuvant chemotherapy treatment, periodic follow-up was decided.