PMON227 Rare ovarian luteinized fibrothecoma as cause of severe hyperandrogenism in a pre-menopausal woman.

Ovarian fibromas and fibrothecomas constitute up to 4.7% of ovarian sex cord stromal tumors (OSCSTs). Luteinized fibrothecomas (LFs) are a histological subvariant of OSCSTs. Typically benign and rare, LFs are mostly diagnosed in post-menopausal women with only 30% in women <30. Only 11% of LFs present with androgen excess (AE). We describe a case of severe hyperandrogenism from an ovarian LF in a young woman with primary amenorrhea and infertility.A 23-year-old woman presented for evaluation of hyperandrogenism. Iatrogenic menarche occurred at age 22, induced by letrozole and medroxyprogesterone (MP). BP was 133/86 mm Hg and BMI was 52 kg/m(2). Exam revealed diffuse obesity, severe hirsutism (Ferriman Gallwey score 29), and severe acanthosis nigricans, but no scalp alopecia, deep voice, violaceous striae or bruising. Total testosterone (TT) was 108 ng/dl (2-45), free testosterone (FT) 24.7 pg/ml (0.1-6.4 dialysis), prolactin 13.2 ng/ml (<30), DHEAS 2308 ng/ml (240-4330), and TSH 1.29 µIU/mL (0.45-5.33). FSH, LH and estradiol could not be interpreted due to unclear timing in cycle. 17-hydroxyprogesterone after MP challenge was 73 ng/dl (<200). Pelvic ultrasound (US) gave normal endometrial stripe of 3.82 mm. Pelvic US and MRI showed polycystic ovarian morphology without masses. CT abdomen showed normal adrenal glands. Ovarian and adrenal vein sampling (OAVS) lateralized AE to the left ovary (LO). LO TT was 5743 ng/dl with associated IVC sample of 139 ng/dl, ratio of 41, and right ovarian TT was 381 ng/dl with associated IVC sample of 32 ng/dl, ratio of 1.18. Just prior to left oophorectomy, preoperative TT was 103 ng/dl, FT 27.8 pg/ml (0.1-6.4 dialysis), and androstenedione (A4) 212 ng/dl (mid-follicular 51-213). Two days post-operatively, TT dropped to 55 ng/dl, FT 11 pg/ml (0.2-5), and A4 105 ng/dl. Pathology revealed a 3.8 cm LF. Six weeks post-operatively, TT and FT normalized to 18 and 3.6 (0.2-5), respectively.Features atypical for PCOS, including presentation outside age 15-25, rapid progression, TT >2× upper limit of normal (ULN), and free androgen index >4× ULN should prompt thorough evaluation. Adherence to guidelines for TT threshold >150 in a pre-menopausal woman and focus on PCO morphology would have provided false reassurance. Maintaining a high degree of suspicion for an androgen-secreting tumor (AST) is paramount when clinical presentation is atypical. OAVS is usually performed when imaging fails to reveal an abnormality, as small ovarian tumors cannot be excluded. Our patient presented with symptoms atypical for PCOS including severe hirsutism and TT >2× ULN, raising concern for an AST. OAVS lateralized AE to her LO. Resection resulted in testosterone normalization and finding of a rare LF. Identifying the source of AE is especially important in women of reproductive age to restore normal reproductive function. Presentation: Monday, June 13, 2022 12:30 p.m. - 2:30 p.m.