Pathology for Urologists
Mixed Gonadal Dysgenesis
- "Asymmetric gonadal differentiation" characterized by a testis on one side and a streak gonad on the other.
- Müllerian derivatives (fallopian tubes) are usually associated with streak gonads (95%) or with testis (74%).
- Hypoplastic uterus and a poorly developed vagina are common findings.
- Clinical: Patients may have clitoriform penis, scrotal testis, and perineal urethral meatus (generally are raised as males) OR they may have cryptorchid testes (more often raised as females).
- 81% of the patients are missing one of their Y chromosomes (45XO/ 46XY) and therefore may show some features of Turner's syndrome.
- Risk of germ cell neoplasia reaches 50% by the 3rd decade, usually beginning with gonadoblastoma. Therefore, testes should be removed prophylactically after puberty.