Testicular carcinoma in situ in subfertile Danish men.

Carcinoma in situ (CIS) testis is the precursor stage for the majority of testicular germ cell tumours (TGCT). Infertility is one of the conditions known to predispose to TGCT, but based on scarce existing data, the prevalence of CIS in this risk group was estimated at only approximately 1%. To establish more objective data, we investigated retrospectively the prevalence of CIS based on testicular biopsies performed in a well-defined group of subfertile males. We included 453 patients who had testicular biopsies performed for infertility reasons during 1995-2005 at the Copenhagen University Hospital (Rigshospitalet). Biopsies were evaluated by two experienced observers independently. CIS was detected in 10 individuals, of whom three had bilateral CIS, corresponding to a prevalence of 2.2% (95% CI 1.1-4.0%). This is greater than the estimated risk of 0.45% for the age- and birth cohort-matched general Danish population. All patients with CIS testis had severe oligozoospermia (</=2.06 million/mL). We confirmed that a thorough examination of men suffering from subfertility/infertility can identify those with an increased risk for testicular neoplasia and recommend performing bilateral biopsies, especially in the subpopulation of men with atrophic testicles, severe oligozoospermia and/or irregular ultrasonic pattern of their testicles.