Undescended testis is a result of testis getting arrested in its path of descent which could be intraabdominal, inguinal, or high scrotal. The retractile testis is a testis which has completed its descent and is a result of hyperactive cremasteric reflex and when manipulated it stays at the base of scrotum temporarily.
The best way of differentiating clinically the retractile testis from undescended testis in older children is to make them sit in squatting position which relaxes the cremasteric reflex and brings the retractile testis down while an undescended testis remains there itself.
In newborns, cremasteric reflex is absent and absent testis in hemi-scrotum is a true undescended testis. So, a documented undescended testis in newborn is always a true undescended testis.
Spontaneous descent of testis is possible only till 3 to 6 months of gestational age. Histological examination of undescended testis has revealed a progressive loss of germ cells and Leydig cells. Hence it is recommended that surgery should be done between 6 months to one year of age.
A good clinical examination is required to locate the position of undescended testis. Imaging studies cannot determine with certainty whether a testis is absent or present. Ultrasound can help to locate the testis in inguinal area, but it is not a good test for locating intraabdominal testis. MRI is a sensitive test to locate testis but not routinely recommended as it is expensive, needs sedation for child and does not change the course of management. The gold standard for locating the testis is diagnostic laparoscopy.
A testis which is palpable requires open orchidopexy. This also requires ligation of patent processes vaginalis.
A testis which is non- palpable can be intraabdominal or atrophic or sometimes difficult to palpable in an obese child. Laparoscopy is the best answer for these testes as it is not only diagnostic as well as therapeutic. It can locate the testis and at the same time testis can be brought down to its normal position.
Intra-abdominal testis