ORIGINAL ARTICLES

PHÆOCHROMOCYTOMA WITH HYPOTENSION AND POLYCYTHÆMIA

539 cases of pheochromocytoma were reviewed with specific attention to those cases presenting with shock at initial evaluation. Eleven such cases were discovered, for an incidence of 2%. A 12th such case is reported here. The literature is discussed with consideration for diagnosis and management of the patient in unexplained shock, suggesting that such patients may be experiencing cardiovascular collapse secondary to massive catecholamine release from a previously undiagnosed pheochromocytoma. Therapeutic considerations are also discussed.

Polycythemia is rarely associated with pheochromocytoma. A patient with a 22-year history of malignant pheochromocytoma is presented in whom major complications developed as a result of long-standing polycythemia, apparently due to secretion of erythropoletin by the tumors. Despite attempts to reduce tumor burden by surgery, chemotherapy, and large doses of 1-131-metalodobenzyl guanidine, polycythemia persisted. Extensive venous thrombosis developed requiring hospitalization and anticoagulation. Thus, polycythemia itself may be a cause of major morbidity in patients with pheochromocytoma, and prophylactic measures may be warranted. Review of the 130 patients with benign and malignant pheochromocytoma studied since the introduction of I-131-metaiodobenzylguanidine in 1980 revealed another six patients with hematocrits over 50 but only one had a hematocrit greater than 55 and required regular phlebotomy. In contrast, anemia (hematocrit less than 35) due to variety of causes was present in 18 cases.

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.