A malignant aldosteronoma

To describe a case of primary aldosteronism due to an adrenocortical carcinoma (ACC) and highlight the need for thorough long-term follow-up. We present the clinical, laboratory, radiologic, and pathologic findings in a patient with ACC and review the related literature. A 52-year-old woman with a history of hypertension and hypokalemia was referred for evaluation of a 6-cm adrenal mass. Her biochemical studies revealed a serum aldosterone-to-renin ratio of 52 without evidence of cortisol, catecholamine, or androgen excess. She underwent surgical resection of this mass, and histologic analysis showed a focally brisk mitotic rate but no evidence of capsular or vascular invasion. In light of these findings, the biologic nature of the tumor was difficult to predict. Thus, it was thought to be an adrenocortical neoplasm. The patient underwent follow-up clinically, biochemically, and with interval computed tomography. Nine years later, hypertension and hypokalemia redeveloped, and she was found to have metastatic ACC. ACC can generally be reliably diagnosed; however, in some cases, the true biologic behavior is difficult to predict. We emphasize the importance of careful clinical, biochemical, and radiologic surveillance in these difficult cases because surgical resection provides the best opportunity for cure in patients with adrenal cancer.