Objective: To differentiate undescended testis into a congenital and an acquired form using earlier information on testis position.
Design: Descriptive.
Setting: Paediatric outpatients' clinic, Medical Centre Alkmaar, the Netherlands.
Method: In a 3-year period (1991-1994), 77 boys were referred to the paediatric outpatients' clinic for non-descended testis. The testis positions in their earlier years were documented. The undescended testis was defined according to these data as a congenital or an acquired condition.
Results: In 23 boys (age: 2.2-12.7; mean: 7.6 years) the testis turned out to be retractile. In 25 boys (0.1-14.3 years; mean: 3.1) the diagnosis was congenital undescended testis; 21 of these underwent orchidopexy. In 29 boys (1.9-14.3 years: mean: 9.9) the non-descent was an acquired condition. Ten of these boys were treated with orchidopexy as initial therapy. In eleven hormonal therapy was given (human chorionic gonadotrophin administered by intramuscular injection) resulting in a fully descended position of the testis in 8 boys.
Conclusion: The phenomenon of acquired non-descended testis is frequent. Incidence and aetiology are insufficiently known. There is no general agreement whether the condition should be treated and which treatment should be favoured. Very likely, the relatively high incidence of orchidopexy operations in the Netherlands is mainly due to operative treatment of the acquired undescended testis.