Nondescended testes.
Found in approximately 1% of 1 year old males.
2-4% of full term male births.
Occurs in 30% of premature infant boys, but 80% descend by the first year of life.
Can be a complete or incomplete failure of the intraabdominal testes to descend into the scrotal sac.
Usually an isolated process but may be seen with other malformations of the genitourinary tract.
Regulators of testicular descent are the Leydig cell derived hormones insulin like factor 3 and testosterone.
Without intervention undescended testes are often associated with infertility reduction, increased risk of testicular germ cell tumors, mainly of the seminoma type, torsion, and psychological problems in adulthood.
RXFP2 (relaxin family peptide 2) and AR (androgen receptor) are receptors for insulin-like factor 3 and testosterone for testicular descent.
There is an association in a small number of boys with genetic alterations in the insulin-like 3 receptor gene (RXFP2) and Klinefelter’s syndrome.
Patients have a 4-8 fold increase in the risk of developing a germ cell tumor.
Orchipexy reduces the incidence of germ cell tumors to a slight degree.
The most common germ cell tumor of the testicle is a seminoma in patients with an undecided testicle.
For patients that have undergone orchipexy the most common germ cell tumors are non seminomas.
In 10% of patients that develop germ cell tumors, the lesion is found in the normal descended testicle.
Biopsy of non enlarged cryptorchid testicle may demonstrate intratubal germ cell neoplasms.