Coexistence of Pheochromocytoma and Primary Aldosteronism due to Multiple Aldosterone-producing Micronodules in the Ipsilateral Adrenal Gland

A 46-year-old woman was referred for hypertension and a right adrenal tumor. Primary aldosteronism (PA) was suspected because of the high plasma aldosterone concentration-to-plasma renin activity ratio. However, a subsequent evaluation revealed coexistent PA and pheochromocytoma. We performed laparoscopic right adrenalectomy. Histology of the resected adrenal gland confirmed pheochromocytoma and multiple aldosterone-producing adrenocortical micronodules. Following adrenalectomy, the urinary catecholamine lev-els normalized, and hyperaldosteronism improved but persisted. Hypertension also improved but persisted and was normalized with spironolactone. The clinical course indicated that the PA lesions were likely bilateral. This was a histologically proven case of coexistent pheochromocytoma and PA due to multiple aldosterone-producing micronodules.