ADRENAL-CORTICAL TUMORS CLINICALLY MIMICKING PHEOCHROMOCYTOMA

The authors report five patients with adrenal cortical tumors in whom the preoperative diagnosis of pheochromocytoma was made. All patients had biochemical evidence of elevated catecholamine secretion in serum or urine. Clinically, two patients presented with symptoms suggestive of pheochromocytoma, and one patient had systemic hypertension that re solved following surgical excision of the tumor. Histologically, the f indings were typical of adrenal cortical tumors: two adrenal cortical carcinomas and three adrenal cortical adenomas. Nevertheless, the immu nohistochemical studies showed evidence of neuroendocrine differentiat ion in four tumors. Three tumors were positive for neuron-specific eno lase and synaptophysin and a fourth tumor was positive for synaptophys in only. All neoplasms were negative for chromogranin. Electron micros copic studies in three tumors showed abundant endoplasmic reticulum an d tubulovesicular cristae consistent with adrenal cortical cell origin . Neurosecretory granules, 150-300 mu in diameter, were found in one t umor. This current series of patients provides evidence that adrenal c ortical neoplasms may be associated with clinical findings that simula te pheochromocytoma (so-called pseudo-pheochromocytoma). These clinica l findings may be mediated by the presence of neuroendocrine features in these tumors.