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The paper by Nah et al1 that highlights late referrals for undescended testes is reflected in many similar epidemiological studies from around the world over recent years, including New Zealand, Canada, Austria and the UK. There continues to be a wide variation in age at diagnosis and age at operation of boys with an undescended testis (UDT). The reasons for this are undoubtedly multifactorial and include the variability of screening programmes, and the different diagnostic possibilities occurring at different ages of a boy's development.
An UDT may be congenital or acquired.
The incidence of a congenital undescended testicle is about 1–6% in term newborns. As stated in the paper, by the age of 1 year, only about 1–2% are undescended. Unilateral incomplete descent is 4× commoner than bilateral. The complications of a congenital UDT include an increased risk of torsion because of abnormal fixation, a 4–8× increased risk of malignancy if the testis is intra-abdominal at birth and reduced fertility if the testis remains undescended. Bringing the testis into the scrotum affects these in various ways depending on the age of orchidopexy, and undoubtedly the risks have to be weighed against the risk of the orchidopexy itself.
A further diagnostic entity is that of an acquired UDT which is defined as a testis that was once in the bottom half of the scrotum but has changed position and ascended out of the scrotum either because of inguinal surgery, for example herniotomy or spontaneous non-surgical ascent. A number …