Undescended testis could be intra-abdominal, inguinal or high scrotal in its location. The retractile testis is a testis which has completed its descent till scrotal sac but retracts back due to a hyperactive cremasteric reflex. A retractile testis can be manipulated back to the base of scrotum temporarily.
Documentation of testis in newborn period is important – In newborns, cremasteric reflex is absent so if one cannot feel a testis in the scrotum it is unlikely to be a retractile testis.
In older children, the best way of differentiating the retractile testis from undescended testis, is to make them sit in squatting position which relaxes the cremasteric reflex and brings retractile testis down.
A good clinical examination is required to locate the position of undescended testis. Ultrasound is not reliable for locating intraabdominal testis. MRI is a sensitive test but cost and sedation are limiting factors for its routine use. The gold standard for locating the testis is diagnostic laparoscopy.
When to treat an undescended testis – Spontaneous descent of testis is seen only till 3 to 6 months of age. It is recommended that surgery should be done between 6 months to one year of age as beyond this age there is a progressive loss of germ cells and Leydig cells. Delay or failure in treatment can result in reduced fertility and increased risk of testicular malignancy in adulthood.
Bilateral undescended testes needs to be evaluated by pediatric endocrinologist