8354 Ovarian Hyperthecosis: An Uncommon Cause of Hyperandrogenism in a Postmenopausal Woman

Abstract Disclosure: M.D. Severino: None. F.P. Silva: None. M.V. Lopes: None. C. Nunes: None. M.I. Alexandre: None. M.J. Bugalho: None. Introduction: Severe hirsutism in postmenopausal women demands a careful clinical evaluation to exclude a malignant cause, such as adrenal or ovarian androgen-secreting tumors. Ovarian hyperthecosis is an uncommon and benign cause of hyperandrogenism and, consequently, hirsutism. It is caused by persistent testosterone synthesis due to proliferation of ovarian stromal cells and nests of luteinized theca cells. It occurs more often in postmenopausal women, as aromatization of testosterone to estradiol decreases due to the loss of granulosa cells. It is also frequently associated with obesity and insulin resistance. Clinical case: We present the case of a 61-year-old woman, with a history of hypertension and dyslipidemia, referred to Endocrinology Clinic due to a year long history of hirsutism, most severe on her face, chest, and abdomen. She also mentioned slight clitoromegaly. She had no other virilization symptoms such as acne, male-pattern alopecia, voice deepening or mammary atrophy. Her menarche occurred at the age of 14 and she had regular menses until menopause, at the age of 51. She had a BMI of 32 kg/m2 and an uncharacteristic phenotype. At observation, she had a mild hirsutism (Ferriman-Gallwey score of 9). This contrasted with the biochemical findings of severe androgenism - total testosterone of 366 ng/dL (reference values RV for women between 5-48) with free testosterone 7.8 pg/mL and SHBG 74 nmol/L (RV 32-128), resulting in a Free Androgen Index of 17,16 (RV 6.6). DHEAS, androstenedione, 17-hydroxyprogesterone and prolactin were normal, and gonadotropins were in the menopausal range. Blood tests also showed hyperinsulinemia and pre-diabetes with HbA1c 6,2%. She denied exposure to steroids in the form of new medication, supplements, or creams/gels (including second-hand exposure through her partner) and she had no exposure to other drugs with androgenic effect. Abdominal and pelvic CT scan, as well as transvaginal ultrasound, showed no adrenal or ovarian lesions. An ovarian cause was deemed the most likely and laparoscopic diagnostic bilateral salpingo-oophorectomy was performed. Gross pathology revealed ovaries of regular size, while histology showed bilateral ovarian stromal hyperthecosis. Testosterone levels returned to normal one month after surgery (14,2 ng/dL). Conclusion: Benign, ovarian causes of hyperandrogenism are uncommon in postmenopausal women, requiring a high index of suspicion. The diagnosis is difficult, and laparoscopic bilateral salpingo-oophorectomy is essential as both a diagnostic and therapeutic tool. Presentation: 6/2/2024