Utility of computed tomography in the localization of the undescended testis.

Computed tomography (CT) was accurate in localizing the undescended testis in eight cryptorchid patients. In three patients the testis was in the lower abdomen, and in five it was in the inguinal canal. In one patient delineation of an unusually large intra-abdominal testis alerted the surgeon to its possible malignant transformation. The advantages and potential pitfalls of CT in preoperative localization are discussed.