Torsion of an undescended testis is a diagnostic challenge as well as a surgical emergency.
The presentation depends on the location of the undescended testis:
(1) location in the inguinal canal may mimic an incarcerated hernia
(2) a more intra-abdominal location may mimic acute abdomen
Since the condition is rare there may be a delay in diagnosis.
Aids to diagnosis:
(1) failure to detect a testis in the scrotal sac
(2) color Doppler ultrasonography
MRI can be diagnostic but may involve a delay in surgery.
Early surgery may preserve viability of the affected testis
