UTILITY OF PLASMA DEHYDROEPIANDROSTERONE-SULFATE DETERMINATION IN ADRENAL INCIDENTALOMAS

To evaluate whether low DHEA-S levels are predictors of cortical origi n, benignity and hormonal activity in incidentally detected adrenal ma sses, thirty-five patients with adrenal incidentalomas were studied. A ll patients were operated on and the diagnosis was histologically conf irmed. Basal endocrine workup included plasma determination of cortiso l before and after dexamethasone (1 mg overnight), plasma ACTH (08:00 h), 17-OH-progesterone, testosterone and potassium, standing plasma re nin activity and aldosterone, supine and standing plasma noradrenaline and adrenaline. If necessary, we performed dexamethasone suppression tests at low (2 mg) and high (8 mg) doses, or the loperamide test (16 mg os) for evaluation of glucocorticoid activity and the glucagon test (1 mg iv) for exploring adrenal medulla function. Plasma DHEA-S was m easured in all patients and the results were compared to those obtaine d in controls matched for age, sex and menopausal status. Suppression of DHEA-S was found in 11 out of 35 patients (31.5%). However, this ho rmonal finding occurred in 50% of the extracortical adrenal lesions, w hile in proven cortical adenomas (no.=19) it was detected in only 5 pa tients (26.3%). Sensitivity, specificity, diagnostic accuracy and posi tive predictive value of low DHEA-S in indicating a cortical origin of the mass were 0.27, 0.0, 0.25, and 0.80. In malignancies (no.=6) low DHEA-S levels were found in 1 out of 2 metastases and never in cortica l carcinomas. Sensitivity, specificity, diagnostic accuracy and positi ve predictive value of low DHEA-S in indicating a benign form were 0.3 4, 0.83, 0.42, and 0.91. Six out of 19 patients with cortical adenomas showed signs of hypothalamic-pituitary adrenal (HPA)-axis dysfunction . Low DHEA-S levels were found in 50% of adenomas with HPA-axis abnorm ality and in 15.3% of adenomas without hormonal activity. Sensitivity, specificity, diagnostic accuracy, and positive predictive value of lo w DHEA-S levels in indicating hormonal activity of the mass were 0.50, 0.84, 0.73, and 0.60. Our data indicate that the association between low DHEA-S levels and adrenal incidentalomas is frequent. Low DHEA-S a ppears to be a poor predictor of hormonal activity with low sensitivit y and specificity in respect of cortical origin and benignity of the m ass. In conclusion, our results show that DHEA-S measurement does not offer relevant clinical information in the management of adrenal incid entalomas. (J. Endocrinol. Invest. 21: 365-371, 1998) (C)1998, Editric e Kurtis.