In this article, state of the art on undescended testis (UDT), a common urogenital abnormality in boys, is presented.
An UDT is defined as a testis, which can not be brought into a stable scrotal position. At present, congenital and acquired forms are recognised. A congenital-UDT is defined as an UDT which has never since birth been descended. An acquired-UDT is defined as an UDT which has been fully descended previously.
Congenital-UDT should be treated surgically between 6 to 12 months of age. The treatment of acquired-UDT is still heavily under debate. Awaiting spontaneous descent at (early) puberty seems to be the most proper treatment.
In the Netherlands, a large number of (late) orchidopexies is due to surgery on acquired-UDT. In order to reduce this large number, the conclusions of the Dutch Development Conference on ‘non-scrotal testis’ should be revised. Likewise, recognition of congenital-, and acquired-UDT as separate entities should lead to a reduced orchidopexy (ORP)-rate in other countries.