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Ovary - nontumor

Gonadal dysgenesis


Reviewer: Mohiedean Ghofrani, M.D. (see Reviewers page)
Revised: 6 November 2011, last major update November 2011
Copyright: (c) 2002-2011, PathologyOutlines.com, Inc.


● A disorder of sex development (DSD) in which one or both gonad(s) is/are undeveloped (streak gonad)
● Disorders of sex development are either female pseudohermaphroditism (46XX with 2 ovaries), male pseudohermaphroditism (46XY with two testes), true hermaphroditism (ovotestis present) or gonadal dysgenesis (either pure with normal 46XX or 46XY chromosomes and bilateral streak gonads, or mixed with streak gonad)


● Pure gonadal dysgenesis (PGD): Both gonads are streak gonads (i.e., dysfunctional gonads without germ cells)
● Mixed gonadal dysgenesis (MGD): Patient has a testis on one side and a streak gonad on the other


● Chromosomal abnormality: may be 46XX, 46XY or 45XO

Clinical features

● Patients with pure gonadal dysgenesis have underdeveloped müllerian organs (sexual infantilism), sometimes with clitoromegaly, while patients with mixed gonadal dysgenesis have ambiguous or female genitalia
● 46XX and 46XY patients present with primary amenorrhea and delayed secondary sexual development; 45XO present with typical Turner syndrome features

Prognostic factors

● Patients with pure gonadal dysgenesis are raised as female since there is no sexual ambiguity at birth; however, gender assignment in patients with mixed gonadal dysgenesis is variable and depends on the degree of virilization
● Approximately 20% of patients with gonadal dysgenesis develop a gonadal neoplasm within the first two decades of life, usually gonadoblastoma; almost all cases of gonadoblastoma have been reported in patients with pure or mixed gonadal dysgenesis or male pseudohermaphroditism
● Other neoplasms include seminomatous germ cell tumors such as seminoma and dysgerminoma, nonseminomatous germ cell tumors such as embryonal carcinoma and choriocarcinoma, as well as non-germ cell tumors such as Wilms tumor


● Given the higher risk of malignancy in dysgenetic gonads, early surgical removal is indicated

Molecular/cytogenetics description

● Pure gonadal dysgenesis: 46XX, 46XY or 45XO
● Mixed gonadal dysgenesis: 45XY/45XO (mosaic)

End of Ovary - nontumor > Gonadal dysgenesis > General

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