Renal artery stenosis, pheochromocytoma and erythrocytosis

Abstract

We present a patient with renal artery stenosis, pheochromocytoma and erythrocytosis. Erythrocytosis preceded the history of hypertension by five to six years and was characterized by an increased red blood cell mass. The plasma volume was normal, as were the white blood cell count, reticulocyte count, platelet count, pulmonary function studies and leukocyte alkaline phosphatase. Erythropoietin assays were negative on blood and urine. The diagnosis of renal artery stenosis was made on the basis of abnormal intravenous pyelogram, abdominal aortogram, renal vein renins, split renal function studies and, ultimately, the response of the blood pressure to nephrectomy. Two urinary vanillyl mandelic acid (VMA) levels during the evaluation were normal. Surgery to correct the renal artery stenosis resulted in a hypertensive crisis and subsequently the diagnosis of pheochromocytoma. Confirmatory evidence included urine metanephrine and free catecholamine levels determined during surgery, and histopathology compatible with a pheochromocytoma. The blood pressure remained elevated after excision of the pheochromocytoma but returned to normal after nephrectomy for the atheromatous renal artery stenosis. The erythrocytosis has persisted. The possible relationships between these conditions are discussed.