title: Cryptorchidism.
abstract: OBJECTIVE
  Cryptorchidism remains a major cause of male infertility and can be associated with germ cell tumors. Recent reports regarding cause, diagnosis, treatment and outcome of this disorder continue to inform our understanding of this common and important problem. The frequency of the problem makes cryptorchidism an area where diagnostic knowledge is particularly important for healthcare professionals.
  
  
  RESULTS
  The literature reviewed in this article approach cryptorchidism from multiple aspects. Reports regarding cause include studies of molecular genetics, endocrine chemical disruptors, the association with galactosemia, the association with low birth weight, and for acquired cryptorchidism, the relationship to infant feeding. In regard to treatment, the benefit of surgical repair at 9 months of age and compliance with recommendations is demonstrated. Further reports continue to document the cryptorchidism's negative impact on fertility, the higher risk of future gonadal malignancy and the lack of function of the unrepaired unilateral cryptorchid testis in adulthood. Management considerations such as the benefit of testicular biopsy at orchiopexy are also reviewed. It was concluded from an analysis of data from the Danish national registry that this can be a valid research tool for future evaluation of the outcome after cryptorchidism.
  
  
  CONCLUSIONS
  Early recognition and surgery, before 1 year of age, remain the most important interventions to reduce the negative impact of both unilateral and bilateral cryptorchidism. Further research is needed to better understand causes of cryptorchidism and the mechanisms by which it exerts its negative effects and to clarify outcome factors to direct the best clinical management of cryptorchidism.
authors.affiliation: Department of Pediatrics, Penn State College of Medicine, The Milton S. Hershey Medical Center, Hershey, PA 17033-0850, USA. plee@psu.edu
authors.forename: Peter A
authors.initials: PA
authors.lastname: Lee
authors.forename: Christopher P
authors.initials: CP
authors.lastname: Houk
mesh_terms: D003131:Combined Modality Therapy; D003456:Cryptorchidism / Q000175:diagnosis / Q000453:epidemiology / Q000503:physiopathology / Q000628:therapy*; D042241:Early Diagnosis; D019317:Evidence-Based Medicine; D006801:Humans; D007231:Infant, Newborn; D007248:Infertility, Male / Q000209:etiology / Q000517:prevention & control; D008297:Male; D008875:Middle Aged; D056126:Orchiopexy; D012307:Risk Factors; D013733:Testicular Diseases / Q000175:diagnosis / Q000209:etiology / Q000503:physiopathology / Q000628:therapy*