SAT-161 - An Elusive Source of Hyperandrogenism: Imaging-Negative Bilateral Ovarian Fibrothecomas in A Postmenopausal Woman

Background: Postmenopausal hyperandrogenism is uncommon and warrants evaluation for androgen-secreting tumors. Ovarian fibrothecomas are rare benign sex cord-stromal tumors that are typically hormonally inactive; however, a small subset may produce androgens and remain occult on imaging, delaying diagnosis.

Case: A 72-year-old postmenopausal woman with type 2 diabetes and hypertension presented with longstanding hirsutism (>20 years) refractory to cosmetic therapies. Laboratory testing showed marked hyperandrogenism with total testosterone 160.72 ng/dL (reference range: 0.00-35.92 ng/dL) and free testosterone 4.86 pg/mL (reference range: 0.50-3.90 pg/mL), with normal DHEA-S (82.0 µg/dL) and androstenedione (1.50 ng/mL), suggesting a non-adrenal source. Abdominopelvic CT and MRI demonstrated no adrenal abnormalities. Pelvic MRI revealed no suspicious adnexal mass. Tumor markers were within normal limits.

Intervention/

Results: Given persistent biochemical hyperandrogenism despite negative imaging, laparoscopic bilateral salpingo-oophorectomy was performed. Histopathology confirmed bilateral ovarian fibrothecomas characterized by a biphasic proliferation of spindle-shaped stromal cells with intermixed theca-like cells. Total testosterone normalized to 21.67 ng/dL at 8 weeks and remained normal at 16 weeks (25.99 ng/dL). Free testosterone decreased to 1.58 pg/mL at 8 weeks and 1.02 pg/mL at 16 weeks. At 9-month follow-up, both total testosterone (22.5 ng/dL) and free testosterone (1.74 pg/mL) remained within the reference range, alongside progressive clinical improvement.

Conclusion: This case highlights that negative imaging does not exclude ovarian androgen-secreting tumors in postmenopausal women. Persistent biochemical hyperandrogenism with normal adrenal markers should prompt consideration of occult ovarian pathology. When clinical suspicion remains high, bilateral salpingo-oophorectomy provides definitive diagnosis and durable biochemical remission.

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