Ectopic cortisol-producing adrenocortical adenoma in the renal hilum: histopathological features and steroidogenic enzyme profile.

Ectopic cortisol-producing adrenocortical adenomas (CPA) are extremely rare, and only four cases have previously been reported so far but the tumors were not ultrastructurally studied. Presented in this paper is the fifth case with ectopic CPA which was extensively examined to gain deeper insights in terms of the histopathological features and steroidogenic enzyme profile of the tumor. A 53-year-old woman complained of accidental discovery of left renal mass. She had a 5-year history of hypertension, weight gain, moon face, thin skin and systemic edema. These symptoms completely relieved after the tumor removal. Two years later, the above symptoms recurred, and a recurrent tumor was revealed in left renal hilum. The tumor was removed completely with relief of her symptoms of Cushing's syndrome. Histologically and ultrastructurally, the tumor was composed of compact cells and clear cells, and the former was prominent, suggesting an active secretory function of the tumor. The adenoma tissue showed a strong immunostaining for Melan-A, 3beta-hydroxysteroid dehydrogenase (HSD3B2) and 17alpha-hydroxylase1 (CYP17A1). Expression pattern for 11beta-hydroxylase 1 (CYP11B1), 11beta-hydroxylase 2 (CYP11B2), CYP17 and HSD3B2 mRNA in ectopic CPA was similar to that in the adrenal CPA. In conclusion, in terms of histopathological characteristic and steroidogenic enzyme profile, ectopic CPA is similar to adrenal CPA, suggesting that they are of identical cell origin.