Cryptorchidism

Cryptorchidism - Cryptorchidism One of the most common male...

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Unformatted text preview: Cryptorchidism One of the most common male developmental abnormalities 27,000 orchidopexies annually in USA 89% of untreated males with bilateral cryptorchidism develop azospermia Lifetime risk of neoplasia 2-3% 4 fold higher than average risk Issues Definitions & epidemiology Normal testicular development and descent Causes of cryptorchidism Consequences Azospermia Increased risk for neoplasia Treatment Medical/hormonal Surgical Definitions Cryptorchid: testis neither resides nor can be manipulated into the scrotum Ectopic: aberrant course Retractile: can be manipulated into scrotum where it remains without tension Gliding: can be manipulated into upper scrotum but retracts when released Ascended: previously descended, then ascends spontaneously Epidemiology Frequency 3.4 % in term boys By 1 yo, incidence 0.8% Is the incidence of cryptorchidism increasing? Literature controversial Cryptorchidism, hypospadias, micropenis Decreasing semen quality Increasing testicular cancer Increasing demand for assisted reproduction Impact of environmental xenoestrogens Herbicides, pesticides, PCBs, polystyrenes Environmental antiandrogens Linuron, vinclozolin, ppDDE, polyaromatic hydrocarbons Risk Factors Hjerkvist 1989 IUGR, prematurity Incidence in premies 30% First-or second-born Perinatal asphyxia C-section Toxemia of pregnancy Congenital subluxation of hip Seasonal (especially winter) Issues Definitions & epidemiology Normal testicular development and descent Causes of cryptorchidism Consequences Azospermia Increased risk for neoplasia Treatment Medical/hormonal Surgical Testicular development 6 wk primordial germ cells migrate to genital ridge 7 wk testicular differentiation 8 wk testis hormonally active Sertolis secrete MIF 10-11 wk Leydig cells secrete T 10-15 wk external genital differentiation Testicular descent 5-8 wk processus vaginalis Gubernaculum attaches to lower epididymis 12 wk transabdominal descent to internal inguinal ring 26-28 wk gubernaculum swells to form inguinal canal, testis descends into scrotum Insulin-3 (INSL3) effects gubernacular growth INSL3 Member of the insulin/relaxin superfamily Highly expressed in Leydig cells In mice, targeted INSL3 deletion associated with bilateral cryptorchidism, abnl gubernaculum development INSL3 Tomboc 2001 DNA analysis of 145 cryptorchid males, 36 controls Found 2 mutations (2/145, 1.4%), several polymorphisms Baker 2002 DNA from 118 cryptorchid boys, 48 controls Several polymorphisms No specific mutations Important in descent but mutations an uncommon cause of cryptorchidism Germ cell maturation 8 wk: gonocytes (fetal stem cells) 15 wk: spermatogonia 3 mo of age: adult dark spermatogonia (adult stem cells) appear and remain Neonatal surge in LH, FSH, T 4 yo: primary spermatocytes Puberty: spermatogenesis Issues...
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Cryptorchidism - Cryptorchidism One of the most common male...

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