The authors report the case of a 46-year-old woman who presented with a 4 month history of paroxystic and recent hypertension accompagned by headaches, tachycardia and sweating. The patient had decreased appetite with epigastric discomfort and abdominal distension. Physical examination was initially normal with mainly normal tension and no abdominal or lombar mass in palpation. While hospitalised, she developed paroxystic crisis of flush, headaches and hypertension of 190/100 mmHg. Biological findings revealed hypokaliemia and normal kaliuria on 3 day samples, with normal glycaemia and normal creatininaemia. Hormonal investigation revealed elevated metanephrines (3 mg/24 hours). Magnetic resonance imaging showed an 11 cm x 8.5 cm retroperitoneal mass with an enhanced signal in T2, a hypotrophic non-functional left kidney and no adrenal adenoma. Clinical and hormonal features suggested a diagnosis of pheochromocytoma. After preoperative medication, open excision, including left radical nephrectomy and adrenalectomy, normalized the catecholamine urinary level, resolved hypokalemia, and improved hypertension. Pathologic examination revealed a well-differentiated liposarcoma, without any pheochromocytoma component, and left adrenal hyperplasia. The tumour cells were immunonegative for chromogranin A. No metastatic lesion was identified by thoraco-abdominal computed tomography.