EXTENSIVE LABORATORY STUDIES OF A PATIENT WITH PHEOCHROMOCYTOMA BEFORE AND AFTER SUCCESSFUL OPERATION: With a Note on the Trial of Piperidylmethyl Benzodioxane to Differentiate Such Conditions from Essential Hypertensive Vascular Disease

PHEOCHROMOCYTOMAS are tumors resulting from the abnormal proliferation of pheochromocytes, or mature cells of the endocrine series that arise from the primitive sympathogonia and normally form the endocrine portion of the adrenal medulla. These tumors may occur wherever there is chromaffin tissue but usually are observed in the medulla of the adrenal gland or in other retroperitoneal locations, such as the aortic chromaffin bodies (organ of Zuckerkandl) on the anterior surface of the aorta near its bifurcation. Characteristically they are localized benign tumors, although occasionally they undergo morphologic changes suggestive of malignant transformation. 1 Their most interesting characteristic is their ability to produce physiopathologic changes, presumably through their excessive hormonal secretions. Therefore, their clinical manifestations are such that the patient frequently is thought to be suffering from a metabolic disease, and an erroneous diagnosis of thyrotoxicosis or diabetes mellitus is likely to be made. In some patients with pheochromocytoma hypertensive