Selective peripheral tissue response to high testosterone levels in an infertile woman without virilization signs

Total testosterone, which is peripherally converted to its biologically active form dihydrotestosterone (DHT), is the first-line hormone investigation in hyperandrogenic states and infertility in premenopausal women. Polycystic ovary syndrome (PCOS), the most common cause of hyperandrogenism and infertility in young women, is often associated with mild elevations of total testosterone. Whereas very high levels of total testosterone (>2–3 SD of normal reference), are most often associated with hyperandrogenic signs, menstrual irregularity, rapid onset of virilization, and demand a prompt investigation. Herein, we report a case of a 32-year-old woman who was referred to the endocrinology outpatient clinic due to secondary amenorrhea and extremely high testosterone levels without any virilization signs. We initially suspected pitfalls in the testosterone laboratory test. Total serum testosterone decreased after a diethyl-ether extraction procedure was done prior to the immunoassay, but testosterone levels were still elevated. An ovarian steroid-cell tumor (SCT) was then revealed, which was thereby resected. Twenty-four hours post surgery, the total testosterone level returned to normal, and a month later menstruation resumed. This case emphasizes that any discrepancy between laboratory tests and the clinical scenario deserves a rigorous evaluation to minimize misinterpretation and errors in diagnosis and therapeutic approach. Additionally, we describe a possible mechanism of disease: a selective peripheral target-tissue response to high testosterone levels that did not cause virilization but did suppress ovulation and menstruation.