Swyer Syndrome With Coexisting Germ Cell Neoplasia In Situ and Gonadoblastoma

Background: Swyer syndrome-46,XY complete gonadal dysgenesis-is characterized by defective gonadal development and manifests as primary amenorrhea and poor breast development in an unambiguous female.Individuals with complete gonadal dysgenesis harbor streak abdominal gonads and are at high risk of developing germ cell tumors, including germ cell neoplasia in situ, gonadoblastoma, and dysgerminoma.Case Report: A 15-year-old patient born of a nonconsanguineous marriage and assigned female at birth presented for evaluation of primary amenorrhea.She had spontaneous breast development during the prior year, but her mother perceived the development to be inadequate.On examination, the patient had Tanner stage 3 breast development, unambiguous female external genitalia, and a normal feminine voice.Investigations revealed hypergonadotropic hypogonadism (follicle-stimulating hormone » luteinizing hormone), 46,XY karyotype, normal female-range testosterone, prepubertal uterus, and bilateral abdominal streak gonads, prompting a clinical diagnosis of complete gonadal dysgenesis.Clinical exome sequencing was unremarkable, and fluorescent in situ hybridization did not reveal SRY gene deletion.Considering the increased risk of gonadal malignancy, prophylactic laparoscopic gonadectomy was performed.Histopathology revealed germ cell neoplasia in situ in the left gonad and gonadoblastoma in the right gonad; close follow-up is planned.Hormone replacement with estradiol valerate was initiated, with a plan to monitor pubertal progression, escalate to adult doses over a period of 1 to 2 years, and add progesterone once breasts reach Tanner stage 5. Conclusion: This case highlights the variability of pubertal development in patients with complete gonadal dysgenesis; the neoplastic potential of dysgenetic gonads; and the importance of early diagnosis, counseling, and multidisciplinary care.