Incidence

Incidence

About 3% of full-term and 30% of premature male infants are born with one or both testes undescended. About two-thirds of these reach the scrotum during the first 3 months of life, but full descent after that is uncommon. The incidence of testicular maldescent at the age of 1 year is around 1%. The condition is sometimes missed in the neonatal period and only discovered later in life. The presence of a hernia, testicular pain or acute torsion may direct attention to the abnormality . Cryptorchidism occurs in approximately 1.5–4% of fathers and 6% of brothers of individuals with cryptorchidism.

Abdominal (15%) Inguinal (25%) High scrotal (60%) Prepenile Transverse scrotal Testicular and scrotal infections • Testicular tumours • Male factor infertility • Testicular trauma •

Incidence

/uni00A0 Testicular torsion a ff ects 3.8 per 100 000 males younger than 18 years annually . It accounts for 10–15% of acute scrotal disease in children. Incidence

Varicoceles are common, a ff ecting 10–20% of adult males. About 90% are left sided, reflecting the proximal venous anatomy – the left testicular vein empties into the relatively high-pressure left renal vein while the right empties into the low-pressure inferior vena cava below the right renal vein. If a left varicocele is identified, there is a 30–40% probability that it is a bilateral condition. They are unusual in boys and typically develop during late childhood and adolescence. Varicoceles occur in around 15–20% of all males but are found in about 40% of infertile males. Incidence

Hydroceles a ff ect an estimated 1% of adult men. More than - 80% of newborn boys have a patent processus vaginalis, but most close spontaneously within 18 months of age. Incidence

Testicular cancer represents around 1–1.5% of male neoplasms and there is clear evidence of an increased incidence of these tumours in the past 30 years with 3–10 new cases per 100 /uni00A0 000 males/per year in western societies. The predominant histol ogy is germ cell tumours (GCTs) (90–95% of cases). The peak incidence of seminomas is in the fourth decade of life, with the non-seminomatous germ cell tumours (NSGCT) being more common in the third decade of life. They are the commonest form of tumour in young men. A specific genetic marker – an isochromosome of the short arm of chromosome 12 (i12p) – is pathognomonic of all types of adult GCTs as well as germ cell neoplasia in situ (GCNIS). Epidemiological risk factors include cryptorchidism, male factor infertility (including Klinefelter syndrome), familial history of testicular tumours among first grade relatives and the presence of a contralateral tumour or GCNIS.