title: [Gonadal dysgenesis and agenesis: anatomical expression].
abstract: The term of gonadal dysgenesis designates generically any anatomical alteration due to abnormal embryological development of a gonad. The spectrum of these gonadal abnormalities is large and includes the following entities: The gonadal agenesis is characterized by a rudimentary streak gonad. It is composed of a dense, hyalinized fibrous tissue in which the germ cells or the germ structures are entirely missing. Usually the gonadal dysgenesis is a bilateral and symmetrical lesion. The gonadal dysgenesis is characterized by the presence of residual germ structures (follicles or tubules). These structures can be more or less easily identified within a dense fibrous tissue. The gonadal dysgenesis alterations are often unilateral and always asymmetrical. Usually the ipsilateral gonad is a testis. The ovotestis is characterized by the coexistence within the same gonad of differentiated germ structures. Most commonly, the gonadal dysgenesis are associated with sexual chromosome abnormalities and an increased risk of neoplastic change (gonadoblastoma). This risk can reach 30% in the asymmetrical gonadal dysgenesis.
authors.affiliation: Groupe de Pathologie Pédiatrique, Hôpital Necker-Enfants Malades, Paris.
authors.forename: C
authors.initials: C
authors.lastname: Nezelof
mesh_terms: D005260:Female; D006059:Gonadal Dysgenesis / Q000145:classification / Q000473:pathology*; D006066:Gonads / Q000002:abnormalities*; D006801:Humans; D008297:Male
vernacular_title: Dysgénésies et agénésies gonadiques expression anatomique.