Undescended testes or cryptorchidism occurs when one or both testicles fail to move into the scrotum prior to birth. The testicles develop before birth in the abdominal cavity and normally descend into the scrotum before birth. The testicles are the male sex gonads which produce sex hormones (such as testosterone which produces male secondary sex characteristics) and sperm for reproduction. Cryptorchidism by definition suggests a hidden testicle: a testicle that is not within the scrotum and cannot be manipulated into the scrotum by several months of age.
Statistics on Undescended Testes
Undescended testes is a relatively common condition affecting approximately one in twenty term males and one in three pre-term males. However, around 65% of the testicles will descend by 9 months of age. By the age of one year most will have descended and the prevalence falls to less than one percent which is similar to that seen in adults. Cryptorchidism can affect one or both testes and approximately 10% of cases are bilateral. For unilateral cases the left testicle is more commonly affected. Studies have shown that the prevalence of cryptorchidism varies geographically but it is not clear whether this is due to genetics or environmental factors. (e.g. endocrine disrupters and lifestyle) is unclear. Cryptorchidism occurs more commonly among patients with congenital disorders of testosterone secretion or action (e.g. Kallmann syndrome- where there is a defect in the development of certain nerve pathways in the brain that help testosterone secretion), abdominal wall defects, neural tube defects, cerebral palsy, and various genetic syndromes including trisomy 18 (three copies of chromosome 18) and Noonan syndrome.
Risk Factors for Undescended Testes
Undescended testes may occur for several reasons. While prematurity is a leading cause, other causes may include hormonal disorders, spina bifida, retractile testes (a reflex that causes a testicle to move back and forth from the scrotum to the groin), or testicular absence. The mechanisms responsible for normal testicular descent are not well understood, which therefore makes it difficult to understand the reason why undescended testes occur in some males. There is some genetic component, as one study has concluded that 6% of fathers of males with undescended testes also had the condition.
Progression of Undescended Testes
Most testicles that are undescended at birth complete their descent within the first few months of life. Those that do not descend themselves will require surgical manipulation to get them into and attached to the scrotum (orchiopexy, orchidopexy). Research suggests that changes related to fertility occur in the undescended testicle in a child as young as one year of age. Thus it is best to treat the condition surgically before these changes occur. In addition, since spontaneous descent rarely occurs after the child is six months of age, the optimal time for surgical correction is as soon as possible after he is six months of age. Men with a history of undescended testes are at greater risk of infertility, malignancy, trauma and tortion later in life.
Symptoms of Undescended Testes
Crytorchidism is usually assymptomatic (no pain or problems urinating) and diagnosed when you or a physician notices an empty scrotum on one or both sides. However, you may also have features of other congenital or chromosomal abnormalities such as hypospadias (abnormal openings of the urethra onto the surface of the penis). Furthermore several other conditions may be associated with the disorder including: Other conditions are commonly associated with cryptorchidism:
- Infertility- Adult males with cryptorchidism may report fertility problems because the testicle is not located in its ideal normal environment for sperm production.
- Poor self image
- Inguina hernias- Where part of the intestines bulges through a defect in the abdominal wall.
- Trauma- An undescended testicle is at higher risk of injury.
- Cancer- The risk of testicular cancer is 10 times higher for males with undescended testicles than for the general male population. The risk of testicular cancer in both testicles exists regardless of whether corrective surgery is performed.
Clinical Examination of Undescended Testes
Diagnosis of undescended testes is made based on a complete medical history and physical examination. Your doctor may ask you specific questions about your family history, early life, puberty and fertility. Examination confirms that one or both of the testicles are not present in the scrotum. Your doctor therefore must carefully examine your genitalia. The undescended testicle may or may not be felt in the abdominal wall above the scrotum.
How is Undescended Testes Diagnosed?
To determine whether the testicle is present or absent, and to determine the possible cause of the undescended testis, your child’s doctor may want to perform a number of tests. These may include karyotype (examination of your chromosome make-up), an ultrasound of the pelvic structures, and a blood test to measure levels of electrolytes, luteinizing hormone (LH), follicle stimulating hormone (FSH), testosterone, mallerian inhibiting substance (MIS), and adrenal hormones and metabolites (e.g. 17-hydroxyprogesterone). These are all special hormones that play a role in testicular development, descent and function.
Prognosis of Undescended Testes
The majority of cases resolve spontaneously, without any treatment. Medical or surgical correction of the condition is usually successful. About 5% of patients with undescended testicles do not have testicles that can be found at the time of surgery. This is called a vanished or absent testis. If one or both testicles do not descend, a man may be infertile later in life. Men who have an undescended testicle at birth are at higher risk of developing testicular cancer in both testes.
How is Undescended Testes Treated?
Undescended testes usually resolves without any intervention by the time that the infant is 6 months old. Resolution occurs as the testicles (or testes) descend from the inguinal canal (a small internal passageway that runs along the abdomen near the groin) into the scrotal sac. If the testicles (or testes) have not descended by 6 months of age, the testicles may not descend at all. Specific treatment for undescended testes will be determined by your child’s physician based on:
- your child’s age, overall health, and medical history
- the extent of the condition
- your child’s tolerance for specific medications, procedures, or therapies
- expectations for the course of the condition
- your opinion or preference
Treatment may include:
- Hormonal therapy: administration of certain hormones may stimulate the production of testosterone, which helps the testes descend into the scrotal sac. This is not routinely used for treatment of truly undescended testes.
- Surgical repair: a surgical repair to locate the undescended testicle and advance it to the scrotal sac may be recommended by your child’s physician. This surgery, called orchiopexy, is usually performed between months 6 and 18 and is successful in 98% of children with this condition.
Undescended Testes References
- Andrology Australia, Undescended testicles, State Government of Victoria, Australia, 2006. Available [online] from URL: http://www.betterhealth.vic.gov.au/bhcv2/bhcarticles.nsf/pages/Undescended_testicles?OpenDocument
- Coller J, Longmore M & Scally P. Oxford Handbook of Clinical Specialties, 6th edition. Oxford University Press, New York, 2004.
- Cooper CS & Docimo SG, Undescended Testes (Cryptorchidism). UptoDate, Web MD, 2004. Available [online] from URL: http://www.utdol.com/application/topic.asp?file=gen_pedi/16379&type=P&selectedTitle=15~25
- Cotran, Kumar, Collins. Robbins Pathological Basis of Disease. 6th edition. W.B. Saunders Company, 1999.
- National Library of Medicine 2004. MedlinePlus Medical Encyclopaedia, Undescended Testicle. Available [online] from: URL: http://www.nlm.nih.gov/medlineplus/ency/article/000973.htm
- Neonatal Handbook- Undescended Testes (Cryptorchidism), RWH, 2005. Available [online] form URL: http://www.rwh.org.au/nets/handbook/?doc_id=660