[Pheochromocytoma--apropos a clinical case].

A case of a 43-year-old woman with severe sustained hypertension resistant to many antihypertensive drugs, frequent hypertensive crisis and symptoms suggestive of pheochromocytoma (symptomatic triad) is presented. Three of the four determinations of the urinary catecholamines metabolites have been normal as it was the only determination of plasmatic catecholamines. Abdominal sonography and CT scan detected a left adrenal mass, that have been histologically confirmed, after surgery, to be a pheochromocytoma. After adrenalectomy, the patient symptoms disappeared but she maintained mild hypertension easily controlled with drugs. The finding of normal plasmatic and urinary catecholamines values in a patient with sustained hypertension may suggest that we are handling with a case of essential hypertension and a superimposed pheochromocytoma with paroxysmal secretion. Some considerations are made essentially about specificity and sensitivity of diagnostic tests.