Introduction/Background Swyer’s syndrome or pure gonadal dysgenesis with XY karyotype (PGD), is a rare disorder of sexual development. It is characterized by a female phenotype with 46,XY karyotype. The risk of degeneration of dysgenic gonads is high. Dysgerminomas are among the tumors that can develop in patients with Swyer’s syndrome.

Results We report a case of a 22 year-old patient with Swyer’s syndrome associated with bilateral dysgerminoma. She was referred for exploration of primary amenorrhea. She has a female morphotype with signs of virilization. She has no turner syndrome dysmorphic features. Secondary sexual characteristics are present and rated S5, P4 and A4 according to Tanner’s classification. She has external female genitalia.

A pelvic ultrasonography showed a small uterus with bilateral heterogeneous adnexal masses. Pelvic MRI revealed a prepubertal uterus, associated with two adnexal masses classified as O-RADS 4. Imaging did not show adenomegaly.

The hormonal assessment showed high levels of FSH and LH, and the genetic test revealed 46, XY karyotype.

Laparotomy confirmed the imaging findings A bilateral adnexectomy was performed and the uterus was preserved. Peritoneal washing cytology and biopsies of the peritoneum were done.

Pathology revealed bilateral ovarian dysgerminoma, staged as Ib according to FIGO classification. Peritoneal cytology was negative.

The decision of the multidisciplinary consultation meeting (PCM) was to complete the treatment with adjuvant chemotherapy. Lombo-aortic and pelvic lymphadenectomy was not recommended.

Disclosures The association of Swyer’s syndrome with bilateral dysgerminoma is extremely rare but it should be diagnosed early. The management of this entity must be multidisciplinary