Ectopic testis

Ectopic testes are a rare congenital anomaly, differing from undescended testis (cryptorchidism) in that ectopic testis is a congenitally abnormally located testis, that has descended from the abdominal cavity away from the normal path of descent while undescended testis are congenitally abnormally located testis within the normal path of descent.

Epidemiology

It is very rare when compared with the incidence of undescended testis, for example ectopic perineal testis has a prevalence of 1% of all undescended testes cases.

Clinical presentation

Empty scrotal sac +/- soft tissue nodule/mass elsewhere (see location below).

Unlike an incompletely descended testis it cannot be pushed into scrotum, and it is liable to injury.

Pathology

Ectopic testis has a deviated normal path to settle in unexpected location outside the abdominal cavity.

Location

The most common region in descending order:

• superficial inguinal pouch which lies anterior to the external oblique aponeurosis
• perineum / anterior to root of penis
• femoral triangle / upper thigh
• contralateral scrotum

Radiographic features

Usually detected by ultrasound examination, which shows an empty scrotal sac with evidence of oval shape structures outside scrotal sac (with similar ultrasound characteristics).

Treatment and prognosis

Treatment is by orchidopexy.

Differential diagnosis

• undescended or incompletely descended testis
• absent or markedly atrophic testis