Sporadic unilateral adrenomedullary hyperplasia with hypertension cured by adrenalectomy

Adrenomedullary hyperplasia (AMH) with increased urinary excretion of epinephrine is regarded as the earliest adrenal manifestation in familial pheochromocytoma; however, pathogenetic mechanisms and morphogenesis involved in the development of sporadic adrenomedullary diseases are unknown as yet. We present 4 patients with clinical, biochemical, imaging, and morphological findings of sporadic unilateral adrenomedullary hyperplasia cured by unilateral adrenalectomy. All patients were hypertensive with intermittent hypertensive crises, and with increased catecholamine concentrations in urine and serum. Correct unilateral localization was achieved by 123-I-BG-scan (planar and SPECT) (n = 2) or cavovenous blood sampling with selective catheterization of both suprarenal veins (n = 2). Histomorphometric analyses revealed diffuse adrenomedullary hyperplasia in all 4 specimens with significant increase of relative volume to 17.6% (controls, 8.7%), and of estimated medullary weight to 0.95 g (controls, 0.45 g); corticomedullary ratio (C:M) was decreased to 5.4 (controls, 11.2). DNA histograms showed euploidy in all cases. In 3 patients, DNA analysis revealed evidence of cell proliferation, but without increase to grade of malignancy indices (0.101-0.523). Adrenalectomy was performed preferentially by a translumbar approach; the operative and postoperative course was uneventful in all 4 patients. Blood pressure without antihypertensive drugs returned to normal in 3 patients, in 1 patient to the upper normal limit.