Perspective on postoperative hormone replacement therapy and fertility preservation in Swyer syndrome with dysgerminoma: a case series and literature review.

[BACKGROUND] 46,XY complete gonadal dysgenesis (Swyer syndrome) is a rare disorder of sex development. Affected individuals present with a female phenotype but have streak gonads. They are at high risk of developing malignant germ cell tumours, such as dysgerminoma. Long-term hormone replacement therapy (HRT) is required after gonadectomy, but the safety of HRT in patients with malignant tumours is not clear.

[METHODS] Case series and long-term follow-up of two phenotypic female adolescents with Swyer syndrome (46,XY karyotype) and dysgerminoma/gonadoblastoma (treated with fertility-sparing surgery + adjuvant bleomycin, etoposide and cisplatin chemotherapy + individualized oestrogen-progestogen HRT). Outcomes (tumour recurrence, uterine development, safety of HRT) were assessed over 6 and 10 years. A systematic review of 17 published studies (24 patients with Swyer syndrome, 30 pregnancies) was also conducted to analyse pregnancy-related outcomes.

[RESULTS] Neither of the two patients experienced tumour recurrence or significant HRT-related adverse events; uterine dimensions increased to near-normal adult size (Case 1: 3.2 × 3.1 × 1.6 cm → 4.4 × 3.6 × 2.1 cm; Case 2: 3.4 × 2.5 × 1.9 cm → 3.6 × 2.9 × 3.8 cm) with preserved secondary sexual characteristics. The systematic review revealed: high maternal comorbidity [83.3 % of pregnancies with complications, including 11 major events such as uterine rupture and haemolysis, elevated liver enzymes, low platelet count (HELLP) syndrome]; elevated preterm birth (35.7 %) and caesarean delivery (89.3 %) rates; and generally favourable neonatal outcomes (mean ± standard deviation birth weight 2704 ± 733 g, two fetal losses).

[CONCLUSIONS] Long-term postoperative HRT (6 and 10 years) in adolescents with Swyer syndrome and dysgerminoma (following curative surgery + chemotherapy) is safe, facilitates near-normal uterine development, and supports potential fertility without recurrence. Fertility-sparing surgery is feasible, and individualized HRT dosing is warranted. The systematic review further confirms high pregnancy-related complications but favourable neonatal outcomes in patients with Swyer syndrome. Vigilant long-term surveillance and large-scale prospective studies are needed to validate long-term safety.