Increased 17β-Hydroxysteroid Dehydrogenase Activity in a Masculinizing Adrenal Adenoma in a Patient with Isolated Testosterone Overproduction

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Abstract
The patient studied had noted the onset of virilization shortly after menopause. Urinary 17-ketosteroid levels were normal, as were fractionated 17-ketosteroid levels by gas liquid chromatography, but for 3 yr, serum testosterone levels had been greater than 490 ng/dl. The ovaries were found to be normal by laparoscopy. Abdominal exploration revealed a 1-cm adenoma in the right adrenal. A part of the adenoma excised from our patient was homogenized and incubated with 5 µCi ;14C=androstenedione. Five percent of the 14C was converted by the tumor homogenate to a metabolite with the same mobility as testosterone on LH-20 chromatography. After thin layer chromatography, the radiolabeled material together with 3H-labeled authentic testosterone were crystallized to a constant specific activity. The net rate of testosterone synthesis by the tumor was 26 pmol⁄mg wet tissue wt.h us. 0.56 pmol/mg-h by a control adrenal homogenate. Thus, the tumor demonstrated a 50-fold increase in 17β-hydroxysteroid dehydrogenase activity compared to normal adrenaltissue. This is the first report to identify altered activity of a specific enzyme system in this syndrome of isolated adrenal testosterone overproduction.