Multiple venous sampling for catecholamine assay in the diagnosis of malignant pheochromocytoma.

Malignant pheochromocytoma is a rare cause of hypertension and still has a high mortality rate. The most accurate way to localize a malignant pheochromocytoma is by a combination of scans, both CT and scintigraphy. Selective sampling of venous blood from multiple sites for plasma catecholamine levels is a safe and reliable technique and may be used successfully in some patients. A case is presented where venous sampling proved to be useful in preoperatively localizing a malignant pheochromocytoma and its metastatic lesions which both CT and ultrasound had failed to demonstrate.