ESPE Abstracts

Introduction: Testicular regression syndrome (TRS) is a rare disease characterized by testicular dysfunction that causes varying degrees of virilization defect according to the emergence period in fetal life. The majority of cases present with normal male external genitalia. However, ambigious genitalia or, more rarely, female external genitalia can be found depending on the extent and timing of the intrauterine accident. Here, we present a case of TRS with normal female external genitalia, mullerrian remnants and streak gonad.

Case: Fifteen-year old female patient was admitted to our outpatient clinic due to primary amenorrhea and absence of breast development. She was born after uneventful pregnancy with birthweight of 2250 gram at 38 gestational weeks. There was no remarkable family history and she has two healthy brothers. The parents were relatives (first-degree cousin). On physical examination, weight was 53.3 kg (-0.28 SDS), height 160.9 cm (-0.12 SDS), blood pressure 100/60 mmHg, and the rest of systemic examination was unremarkable. According to Tanner stage, pubic hair was stage 3-4 and breast development was stage 1. She has normal female external genitalia with separate vaginal and urethral openings and there was no cliteromegali or palpable gonad. Laboratory examination revealed normal kidney-liver-thyroid function tests, ions, morning cortisol / ACTH, and DHEA-S. In addition, LH (39.4 mIU / mL) and FSH (83.0 mIU / mL) were markedly high; estrogen, anti-mullerian hormone, and inhibin B levels were low. Pelvic ultrasonography and MRI showed no uterus or gonads. The lumbar region bone mineral density was decreased (L1-4 0.554 g / cm²; -4.46 SDS). Karyotype was 46, XY and SRY was positive. Further genetic analysis by next generation sequencing of genes involved in the development of gonad revealed no mutation. Laparoscopic evaluation showed mullerian structures (rudimentary uterus and fallopian tubes) and streak gonads. Bilateral gonadectomy was performed. The pathological examination revealed spermatic cord, immature seminiferous tubules, and leydig cell groups in the stoma. There was no evidence of neoplasia. Estradiol treatment for pubertal progression was started.

In conclusion: Antenatal or perinatal vascular thrombosis or torsion are thought to be the causes of TRS; however, the precise etiology has yet been identified. Patients with TRS present with different phenotype depending on the occurrence period of testicular dysfunction. However, female external genitalia are rarely reported. TRS should be kept in mind in cases with female external genitalia but male karyotype with 46,XY, elevated gonadotropins, and mullerian remnants.