A patient with preclinical Cushing's syndrome and excessive DHEA-S secretion having unilateral adrenal carcinoma and contralateral adenoma.

We report a case of preclinical Cushing's syndrome in a 54-year-old male associated with bilateral adrenocortical tumours. Physical findings and general laboratory data were unremarkable except for mild hypertension (158/90 mmHg) and impaired glucose tolerance. Endocrinological evaluation revealed the presence of autonomous cortisol secretion including unsuppressible serum cortisol by 8 mg dexamethasone test (11 microg/dl), high serum DHEA-S (3580 ng/ml, normal: 400-3500) and increased urinary 17-KS excretion (31.0-35.8 mg/day, normal: 5.8-21.3). CT scan demonstrated the presence of tumours in both adrenals and bilateral adrenalectomy was subsequently performed. Histological examination of the resected specimens revealed an adrenocortical carcinoma on the right side and an adenoma on the left side with noticeable cortical atrophy in non-neoplastic adrenals. Immunohistochemical study of steroidogenic enzymes demonstrated that all the steroidogenic enzymes involved in cortisol biosynthesis were expressed in both right and left adrenal tumours. Enzymatic activities of 21, 17alpha, 18, 11beta-hydroxylases were detected in both right and left adrenals except for the absence of 11beta-hydroxylase activity in the left adrenal adenoma. Results of in vitro tissue steroidogenesis examined in short-term tissue culture of the specimens revealed no significant differences between carcinoma and adenoma in cortisol production, but the production of adrenal androgens in carcinoma was significantly higher than that in adenoma, which may indicate the importance of evaluating adrenal androgen levels in patients with adrenocortical neoplasms.