dysgenetic gonad

Digital cases

 HPC:271 : 46,XY Pure gonadal dysgenesis. Streak gonad.
 HPC:384 : Gonadoblastoma in 46,XY gonadal dysgenesis

The detection of Y chromosome material in a dysgenetic gonad is extremely significant, due to the high risk of malignant transformation.

Types

 46,XY gonadal dysgenesis
 46,XX gonadal dysgenesis

See also

 gonadal dysgenesis

• pure gonadal dysgenesis
• mixed gonadal dysgenesis

Synopsis

 primitive sex cord components

Etiology

 mixed gonadal dysgenesis
 complete gonadal dysgenesis (pure gonadal dysgenesis)

Tumoral predisposition

Because 20%–30% of children with XY complete gonadal dysgenesis (CGD) and 15%–20% with mixed gonadal dysgenesis (MGD) develop a gonadal tumor within the 1st or 2nd decade of life, streak gonads should be removed.

The presence of a well-defined part of the Y chromosome (GBY or gonadoblastoma locus on the Y chromosome) is implicated in the development of malignant neoplasms in dysgenetic gonads.

Gonadoblastoma is the most common tumor, usually arising from intraabdominal dysgenetic gonads, and is considered to be a precursor to the development of type 2 germ cell tumors seen in these patients.

Type 2 germ cell tumors include:
 (a) seminomatous tumors such as seminoma and dysgerminoma,
 (b) nonseminomatous tumors such as embryonal carcinoma and choriocarcinoma.

The presence of an echogenic focus at US associated with the pelvic organs or found in ectopic gonadal tissue within the inguinal canals or labioscrotal folds should be regarded with suspicion, since gonadoblastomas often calcify.

There is increased risk of developing Wilms tumor, when XY gonadal dysgenesis is associated with glomerulopathy in Denys-Drash syndrome. The average patient age at the time of development of Wilms tumor in Denys-Drash syndrome is 3 years.

Screening for Wilms tumor with renal US every 6 months to 1 year up to school age has been recommended in children with dysgenetic gonads.

See also

 disorders of sex development (DSDs)
 Prader 3-4 external genitalia
 palpable structure in the inguinal canal
 gonadal tissue
 streak-like gonad
 dysgenetic testis
 ambiguous genitalia
 dysgenetic gonad
 sex chromosome mosaicism
 45,X/46,XY mosaicism
 malignant transformation
 primitive sex cord