Adrenocortical carcinoma manifesting pure primary aldosteronism: A case report and analysis of steroidogenic enzymes

Adrenocortical carcinoma manifesting pure hyperaldosteronism is extremely rare. We report here a 61-year-old woman with biochemically proven primary aldosteronism due to right adrenocortical carcinoma. Computed tomographic scan showed 4.5×5.3 cm lobulated mass with tiny calcification, while there was no significant uptake of 131I-iodomethyl norcholesterol in the tumor. Immunohistochemical analysis demonstrated expression of steroidogenic enzymes in the tumor tissue: P-450scc, P-450c21, 3β-hydroxysteroid dehydrogenase, P45017α, and P-45011β. In addition, we could demonstrate mRNA expression of aldosterone synthase (P-450aldo: CYP11B2) in the tumor by specific ribonuclease protection assay. This is the first report of a case of primary aldosteronism due to adrenocortical carcinoma, in which expression of all sets of steroidogenic enzymes required for aldosterone synthesis was proven.