Steroid secretory characteristics of a virilizing adrenal adenoma in a woman

Abstract

Abstract A tumour of the left adrenal gland was identified in a woman who presented with virilization and secondary amenorrhea. Preoperatively, the plasma levels of dehydroepiandrosterone sulphate, dehydroepiandrosterone, androstenedione, testosterone, 5α-dihydrotestosterone and 5-androstene-3β,17β-diol were elevated two- to fourfold whereas those of urinary 17-ketosteroids were elevated more than tenfold. The production rate of dehydroepiandrosterone sulphate was more than 16 times that in normal women whereas those of dehydroepiandrosterone, testosterone and androstenedione were approximately twofold greater; plasma testosterone was derived almost entirely from the peripheral conversion of androstenedione. Blood was obtained by catheterization of the ovarian veins, left adrenal gland vein and inferior vena cava (at two different sites) and plasma steroid levels were determined: testosterone and cortisol levels were elevated in all blood samples whereas those of androstenedione, dehydroepiandrosterone sulphate and 11-desoxycortisol were approximately six- to eightfold, 1·5-fold and nine- to 22-fold higher in the effluent of the left adrenal gland/tumour compared with the levels in the other compartments. Blood was collected hourly for 24 h to determine steroid levels under basal conditions and, also, after ACTH treatment. Plasma cortisol levels increased markedly upon ACTH administration and fell to very low levels 11 h later, but those of androstenedione, testosterone, dehydroepiandrosterone, 5-androstene-3β,17β-diol and dehydroepiandrosterone sulphate were not affected by ACTH treatment. A histological diagnosis of cortical adenoma of the extirpated tumour was made. Tissue explants and adenoma cells were maintained in culture to characterize the steroid-metabolizing properties of the tumour. The secretion of dehydroepiandrosterone sulphate by tissue explants was high initially, but declined to almost undetectable levels after 5 days in culture. In the presence of ACTH, dehydroepiandrosterone sulphate secretion remained elevated throughout the entire study up to 5 days. Basal secretion of dehydroepiandrosterone sulphate, androstenedione, 11-desoxycortisol, cortisol, testosterone and 11β-hydroxyandrostenedione by adenoma cells was either very low or undetectable. In the presence of ACTH, dibutyryl cyclic AMP or cholera toxin the secretion of dehydroepiandrosterone sulphate, androstenedione and 11-desoxycortisol increased markedly with time in culture up to 3 days, whereas the other steroids were undetected in the medium. A homogenate of adenoma tissue metabolized testosterone to androstenedione, but the conversion of androstenedione to testosterone was minimal. The findings of this study served to establish that virilization in this woman was due, at least in part, to excess testosterone – and testosterone-derived 5α-dihydrotestosterone – produced at extra-adrenal tissue sites almost exclusively through metabolism of tumour-secreted androstenedione. The excess production of steroid prohormones in this woman was due to autonomous tumour steroidogenesis. The remarkable feature was the degree of virilization resulting from a modest increase in biologically potent androgens. Journal of Endocrinology (1994) 140, 297–307